What should a computer mouse be like? Computer mouse repair. Computer mouse
Have you ever wondered how things work, what path they take from idea to implementation, how simple simple things are? How easy is it to make a comb? What about a computer mouse? What about a wooden computer mouse made from a single block of mahogany with an LCD screen, with its own electronic filling and a cable made and braided especially for it? I think you will be interested in my journey that I went through during the 2.5 years of creating my mouse.
Design, construction, modeling
Since I was a complete zero in design, I approached the matter as a complete layman. I bought plasticine and started sculpting the mouse of my dreams.
First, I built a mouse that is ideal for me to use on a desktop. She is big and dark gray in the photo. Then I made a mouse that would suit me as a mobile mouse (small dark gray). And then I took the piece of plasticine I had stolen from the children to work, and my colleagues sculpted a mouse that claimed to be the “folk mouse.” It fit perfectly into the hands of the majority of the male population of our team (multi-colored in the photo). And what? The result is banal and dull forms that we twitch with our hands in every possible way day and night. Apparently, among the three standard mice, any user will find a comfortable one. The triumph of the ideal?
As a result, a mouse was modeled behind the computer, which, from my point of view, pretended to be elegant and beautiful.
At that moment I really liked her. And without thinking twice, I divided the computer model into parts. Elements of fastening and interfacing with electronic filling were thought out. It sounds simple, but in reality hundreds of hours of painstaking work were spent.
After this, the resulting parts were grown on a 3D machine to test assembly.
Material - polyamide. It fits well in the hand, like a glove. All parts fit together, technological assembly also went without problems
The next stage is milling in wood. I probably purchased a dozen different species of mahogany trees, but I started with the sapele tree, the rest of the species are waiting in the wings.
I didn't like the design in real life. The vertical gaps between the buttons and the case looked bad and untidy. Technological “sores” when working with wood are visible - chipping and removal of wood. Well, and most importantly, the keys did not bend, there was no click.
I thought about the design for a long time. Something was confusing, and there was no feeling of satisfaction. Then I realized that the mouse lacks solidity. I decided to return to the original version of the mouse, which I sculpted at the very beginning, only at a professional level and using sculptural plasticine. There are two design options in one mouse. Convenient for comparison and decision making.
After receiving the final version, 3D scanning was done and the surfaces were transferred to SolidWorks.
The second model turned out not much more successful than the first. The buttons were not being pressed and there was no way to fix this in the current model. The model's marriage was laid down at the DNA level. We need a more comprehensive approach with simultaneous control of both design and technology. Otherwise nothing will work. There will be either technological excellence or good design, but not all at once. These characteristics sit on opposite sides of the seesaw. So I throw everything in the trash and start over. Sketch-design-sculpting-testing-growing and so on, but with technological control of critical parameters on the one hand, and design on the other. We are looking for a middle ground.
The third model was made within the framework of the classic product design cycle. I started with a sketch.
Contours are drawn.
And finally, the approved design.
Plasticine model.
3D scanner, surface acquisition.
Computer model.
Then the process of finishing the body began. The body was cut out on a CNC machine, tested, modified, and then cut out again. As a result, only the tenth version of the case turned out to be functional. The biggest problem was making the keys comfortable to press. As a result, in some places the thickness of the wood decreased to 0.7 mm! It took me a year to refine the body.
The wheel and connector were also made of wood.
I laser engraved the wheel with the Clickwood brand.
The eleventh version of the case is coming, to which I will make minor changes. I also started developing a wireless version of the mouse. The wireless module is based on Bluetooth technology, the optosensor is laser. AAA size batteries, 2 pieces, replaceable. When recharging, the mouse will continue to work. All the elements are arranged very tightly, so I had to rack my brains quite a bit when assembling them. A cavity specially cut into the wooden body of the mouse serves as a container for batteries.
Wooden parts
Working with wood begins with the selection of wood. The boards must have the correct geometry, have a minimum of knots and defects, and have the required moisture content.
First, the boards are dried at home. At least six months.
After this, the board is sawn into small bars, which are dried for several weeks at the site of their further processing. At all stages, humidity is controlled by a special device. If the drying process is neglected, the wood loses geometric stability, and the manufacture and operation of the mouse becomes impossible.
The prepared bars are processed on a CNC machine using a specially created program.
From the very beginning of creating a part until the final assembly of the mouse, the parts are rigidly fixed to metal equipment so that at no stage does the part change its shape and geometric dimensions.
The processing of the upper part of the mouse has to be done with pinpoint precision, since its profile is designed for a soft click and is very thin in some places. I control the pressing force with a grammeter. In normal mice it ranges from 50 to 75 GS. I'm trying to achieve 50 GS.
Wood is the biggest challenge in my project. Not only is this the most significant part of the cost, but the percentage of defects here is very high. Wood is an anisotropic material. It may fail, there may be defects, chips may occur, and simply an error in the finishing technology can lead to the mouse body being thrown into the trash. I admit that I am still improving the processing technology, and I am not completely sure that I have found the right one. For statistics: in the first batch of ten cases, only three reached the finished product. Therefore, the part of the technological chain related to wood is critically important for the cost and quality of the finished product. It is constantly being worked on.
In the future I plan to work with bone. In particular, I am already creating a wheel from bone.
Electronic part
I developed the first mouse design myself. The sensor was a top-end optical sensor ADNS-3090 from Avago, the brains were an Atmel controller, and the rest were components from brand companies like Murata, Yageo, Geyer, Omron and Molex.
I paid special attention to the high-quality nutrition of the mouse, here, in my opinion, I reached the absolute level with my perfectionism
The first working breadboard.
In black version, final.
There were also experiments with different buttons. I always tried to choose a quiet mouse among others. Well, since I’m making it myself, I decided to conduct an experiment and make such a mouse and try it out. To do this, I replaced the clicking left and right “micrics” with soft and quiet ones used for the central button (have you noticed that the central button always clicks quieter?). A special version of the board was created, on which all three identical “micrics” were mounted.
I selected and bought a batch of gold-plated connectors for the mouse. As usual, in China. I don’t know about “better contact”, but they harmonize perfectly with the wood.
Screen, firmware
Fascinated by the idea of placing a display in a mouse, I began searching for it among hundreds of suppliers. The requirements were simple: strict dimensional restrictions and the ability to at least symbolically display at least eight familiar places. While I was selecting it, I learned almost everything about displays. They differ by type: symbolic and graphic, by technology: TAB, COG, TFT, OLED, LCD, E-Paper and others. Each type or technology has a lot of varieties, sizes, colors, lighting, etc. In general, there was a lot to dig into.
After surfing half the internet, I found out that the size I needed was made by only one company in the whole wide world. All other options are definitely larger in size. And even the display I found barely fit inside the mouse. As an option, a custom display was considered, which could be made for me according to my requirements, but this is a very expensive option for me (about one hundred thousand rubles). For the first model, a graphic display with a resolution of 128 by 64 pixels is quite suitable, which is what I chose.
In order to figure out how the display actually looks and fits with my mouse, I had to order all varieties of this display from the manufacturers. What do these varieties mean? The model name consists of unpronounceable alphanumeric combinations like FP12P629AU12. All of them are assembled from various blocks and are clearly deciphered in the specification. For example, the example given can be assembled from blocks FP.12.P.629A.U12, where the type, size, voltage, controller, operating temperature range and other information about the model are encrypted. And the last block is the trickiest. It can have several dozen values, each of which means one or another combination of such characteristics as the presence and color of the backlight, background color, symbol color, and the range of degrees from which information can be clearly read. These are the parameters that were interesting to me.
As a result, “for testing” I ordered 18 different modifications. The manufacturer agreed, but said that the minimum order was 5 displays for each modification. There was nowhere to go, and I had to agree, knowing that 90% would go into the trash can. And then, one cloudy day, the express delivery service brought me home a huge box in which a homeless person of average build could live. The box contained 18 smaller boxes, each of which comfortably accommodated 5 displays, securely secured for a long trip to cold Russia. There was so much accompanying packaging that it was enough for my mother-in-law to cover several beds for the winter.
As a result, after thorough tests on a specially assembled stand, two displays turned out to be suitable for the series. They differ only in background: gray and yellow-green. These are the ones I will offer to complete the mouse. By default I plan to set it to yellow-green, but two more options will be available: a display with a gray background and a mouse without a display at all.
But the main intrigue was what information can be shown on the screen? I was offered different ideas: ambient temperature, indication of the arrival of letters, something else that was not very original.
My train of thought followed a different path. Let's start with the fact that there are two significant restrictions on displaying operational information: the presence in front of the user of a huge and high-quality source of any information (monitor) and the need to turn the mouse over to obtain information. In addition, the screen is small, the resolution is low, and the LED interferes with normal reading. Therefore, I came to only one conclusion: the information should be of an entertaining nature only, the practical value of which tends to zero, but at the same time the WOW! effect should be killer.
What kind of information can have such properties in a device of mediocre complexity? There is not much of it: mileage, time of use, speed of movement, number of clicks and scrolling of the wheel. I decided to abandon the last parameter, since it seemed uninteresting to me. All other parameters are tied to the session (the last time the mouse was used from the moment power was supplied to it, i.e. connecting to the computer or turning on the computer itself) and to the entire lifetime of the mouse. For example, the user can find out at any moment how many times he pressed the left mouse button or how many meters his mouse has traveled in meters today or since the time of its purchase. The information is absolutely useless, but it will help those who are especially curious to understand how much he torments the mouse. If other interesting ideas appear, they can be implemented with new firmware.
I also added general information about the mouse (model, mouse and firmware number, month of manufacture) and a settings screen. You can choose the language and system of measures (English or metric). To store all this information, we had to add permanent storage flash memory to the circuit.
To fit this amount of information, I had to break everything down into screens. Each screen displays one type of information and shows session and all-time parameter values. There are six screens in total, which can be changed using the mouse wheel.
The first option was implemented in a purely textual manner, for which several font options were even developed.
I made a firmware to evaluate how the text looks using the created font on the mouse screen. It looks terrible, what can I say.
Now it has become obvious that the screen needs graphics, and not a set of symbolic information. Therefore, I brought a designer into the work, and together we prepared three graphic options; in the end, the second option was recognized as the most successful.
Of course, this design required higher resolution, so it had to be adapted.
But that's not the end of the story. After I selected the mouse screen, I ordered a trial batch for breadboards. As a result, screens arrived, but for some reason the number of pins differed from what was indicated in the specification (datasheet). In response to the request, the manufacturer received an answer that everything was fine, this was a minor modification, and it would not affect the performance in any way. Meanwhile, the missing two wires were responsible for the brightness of the displayed graphics.
It was all very suspicious. And just like he was looking into the water. We remade the board for a modified screen, soldered it, and then it turned out that the screen was completely dim. It's as if the device's batteries are dead. And this became clear after a long and painstaking work of searching and selecting screens, purchasing a trial batch of all modifications and testing them. Time, money, and so on.
But the story turned out to have a good ending. After correspondence with the Chinese, it turned out that the screen can now adjust its contrast directly from the firmware. We repaired the firmware, and everything started to show just fine!
Everything is shown as planned: mileage, speed, number of clicks, etc.
Subsequently, the firmware also changed several times: a setting for changing the language appeared. Two languages on one screen are bad - readability deteriorates, Cyrillic abracadabra will only irritate an English-speaking user, and support for other languages may be needed in the future. The difficulties began when I tried to adjust the mouse travel. It seems that there is something complicated: the optical sensor transmits the increment in two coordinates, which must be converted to a system of measures and added modulo to the current value. That's the whole mileage.
But, as it turned out, not everything is so simple. Two people with mice with the same sensor installed can get radically different results! The thing is that the resolution of the sensor (sensitivity) very much depends on the surface on which the mouse is rolling. The best results are obtained when the mouse rolls on white paper. Slightly worse on wood and fabric. It's really bad for laminate and film. The declared sensitivity is achieved only on ideal, from the point of view of the sensor, surfaces.
This makes no difference to the end user. He connects the mouse and, through trial and error, sets the operating system to a comfortable cursor speed. The system remembers this coefficient and uses it to increase or decrease the movement coordinate increment values.
But it’s a completely different matter if you plan to read these parameters directly from the mouse. The mouse on one surface will show the result of running one meter, on the other - one and a half. Speed will also lie. And something needs to be done about this.
To solve this problem, we had to introduce the “Sensitivity” parameter, which allows you to individually select the coefficient for each surface. By default it is equal to one, which corresponds to the surface of white paper. It can be increased or decreased in the settings. You don’t have to touch it at all, everything will work just fine as is. But for true perfectionists, the leaflet included with the mouse will contain a table from which you can select a coefficient for the existing surface and instructions on how you can independently configure the mouse to show the exact mileage.
During the development of the firmware, another side effect of the sensor was discovered. If you take the mouse and simply wave it in the air, the mileage readings will also change. This is due to the fact that the sensor detects the surrounding space as a certain surface and also tries to obtain mouse offset values. Therefore, you can observe the following effect: you turn the mouse over, look at the mileage parameters and are surprised that they change upward right before your eyes. Of course, you can install a tilt angle sensor in the mouse that turns off the sensor while it is turned over, but doing this only for the situation described is unreasonable. Perhaps it will appear in the next version, but not now. After all, the mouse is raised only to look at the indicators, and 99.9% of the time it is on the surface and receives the correct information.
Cable
I decided to make the cable as flexible as possible so that it would not interfere with the movement of the mouse and would be “invisible” for kinematics. Well, I personally don’t like the “spring” cable.
Sometimes it seems that when creating a product, the cable is the most insignificant part of the product. What's easier is to buy the required amount of cable in the store and unsolder it. No big deal. But, alas, not here in Russia. Sometimes it seems that our industry is no longer capable of making anything more complex than cast iron irons. Attempts to find a cable resulted in a three-week search and shaking up the assortment of absolutely all manufacturers of Russian cable products. It turned out that our standards do not describe a cable suitable for modern electronic devices. For example, a four-core microphone cable with a KMM 4x0.12 mm2 braid has an outer diameter of 5 mm. That's a lot. Older mice and keyboards have a seemingly thick cable that is only 3.5mm in outer diameter. The closest analogue on sale was a cable from the German company Lapp Kabel, but its outer diameter was just 3.5 mm. Now imagine the braid on such a cable. Introduced? I'll tell you that I saw a similar cable on power cords for irons
So, it turned out: you can’t buy such a cable in Russia. Dot. Well, we are not used to retreating. I go to production and try to order, fortunately they still make cables in Russia. And to do this, let’s define my requirements. So what do I need:
The cores are copper, made of braided wires (for flexibility).
Number of cores - 4.
Screen - yes.
Flexibility - maximum.
The outer diameter of the cable is strictly no more than 3 mm.
Color - Pantone 4625 C.
Bottom line: I tried to contact probably a dozen possible manufacturers of cable products; no one is interested in messing with my order. They didn’t even ask what mileage I needed. Bottom line: such a cable cannot be purchased or produced in Russia. Sad. But we are not used to retreating.
I go to Alibaba.com. I find the first Chinese manufacturer I come across, write a letter and literally within a few hours I receive an answer: we will make any cable for you! I'm shocked. I send him the specification, money for delivery, and a week later I receive a sample. Wow! And I lost almost three months, trying to patriotically place an order in Russia. It turned out that the Chinese could easily make me a cable with an outer diameter of 2.5 mm.
As a result: I ordered 4 different samples from China. At first I was not satisfied with the scratchability and dullness of the outer shell, then I was not satisfied with the flexibility of the cable, then again I was not satisfied with the flexibility, and in the end I settled on the last sample sent, which I was ready to order. They couldn't be more flexible. The cable has memory. As a result, I accidentally received a cable with memory, although I wanted one that was as flexible as a rope
I ordered a kilometer, two weeks later I had the cable. Total time spent: six months.
Braided my kilometer of cable. There were two options.
Approximately 10% of the cable was rejected. This is the beginning of the bays, where the braid is unraveling and the machine has not yet entered operating mode. And some places where, for some reason, loops and knots of braiding threads formed.
If the end of the cable is not sealed with heat shrink, it will fluff up immediately, the threads are synthetic! Therefore, the installation of the cable assembly is complicated by the preventive attachment of heat shrink.
The outer diameter of the braided cable was 3.2 mm, i.e. The braid added 0.7 mm to the cable diameter. It doesn’t seem like much, but a regular mouse usually has a cable with a diameter of 3.5 mm, and in the era of wireless mice it seems thick and heavy. Recently, non-budget mice have begun to be equipped with cables with a diameter of 3 mm, and they no longer interfere so much during work; they are almost invisible. But the keyboard cable can have an outer diameter of 4 mm. And even more. But this doesn't matter for the keyboard.
Plastic parts
No matter how much I would like to make the body parts of the mouse entirely from wood, I cannot do without plastic. You need legs, an axle for the wheel, a support for the axle and a piece of glass for the display.
Therefore, I had to order a mold from the Chinese.
After each test casting, the Chinese sent me a dozen samples, which I tested on my mouse.
As a result, I modified the mold three times until the quality began to satisfy me. The problems were different. For example, after assembly I got a problem with dust that formed between the display and the protective glass. It looks untidy. Moreover, the mouse will scratch on the surface, and dust will gradually accumulate there. I had to convert the glass into a container with sides where the display would be placed, after which the contour would be sealed.
The result is something like this.
Refining a mold is not an easy task at all, and changes can only be made in the direction of making the part larger. Therefore, any inaccuracy or error can ruin the entire work. For reference: each revision means a month and a half of waiting for new samples. And the change itself could be microscopic, but necessary.
I won’t dwell on plastic parts; this technology is now leading, and I can’t tell you anything new or interesting here. I’ll just say about the legs, for which I spent a long time selecting a material with reduced friction, after which I conducted tests and “races” of mice in order to determine the winner with minimal friction.
Processing and coating
First, careful work is carried out with the removal of lint, sanding and polishing of the surface.
I had a difficult task ahead of me. It was necessary to stabilize the wood so that the geometry of the mouse did not change depending on humidity, and to protect the wood from working in an aggressive environment (sweat and grease from the hand).
From the very beginning I refused varnish. Varnish is a surface film that eventually cracks and breaks down, leaving the wood bare. Sweat and fat penetrate the pores, the wood darkens, and the irreversible process of its degradation begins. Therefore, it was decided to use oil as impregnation and protection, and wax to give a commercial look.
To make it clear: the tree is completely saturated with pores, which contain either air or the oil of the tree itself (if the tree is a rubber tree). Our task is to fill the pores as much as possible with our oil, which should then polymerize and protect the wood.
In order not to prolong the story, I will say that I tried a lot of oils: linseed, teak, tung, Vaseline, Danish. Each oil has its own character. For example, wax is very difficult to apply to teak oil, while linseed oil takes a very long time to polymerize. Therefore, it is necessary to introduce a catalyst into it - a drier.
I ended up developing two technologies. The first is the technology of vacuum impregnation of wood. It works like this: I create a vacuum in an environment with oil and wood. Air begins to escape from the pores. After removing the vacuum, the pores are filled with oil. As a plus, the tree is well stabilized. The downside is that it gets very dark. Looks good, but not for everyone.
The second technology is surface coating with oil. The oil is applied 1-2 or more times with a non-woven cloth.
Apply carnauba wax.
And rub with a muslin circle.
Then, using a hair dryer, I “dissolve” the dry wax residues in narrow and difficult places. In the case of “insoluble” debris, I pick up a toothbrush with stiff bristles, remove the debris, and then repeat the waxing procedure locally again.
If we evaluate the labor costs of processing, then manual labor for one mouse is about four hours.
Assembly
Next comes the installation operation, but before it you still need to remove traces of processing from the technological holes. Then, using a special 3M tape, I adjust and glue the legs (the body can move by a fraction of a millimeter, and this will be immediately noticeable: it will wobble like a lame stool). Then I lay the cable, mount the board, support, install the wheel and also, if necessary, adjust the buttons (there should be no chatter) and pressing force. This operation can also take up to four hours.
In this article, we will look at the principles of operation of optical mouse sensors, shed light on the history of their technological development, and also debunk some myths associated with optical “rodents”.
Who invented you...
Optical mice that are familiar to us today trace their origins back to 1999, when the first copies of such manipulators from Microsoft, and after some time from other manufacturers, appeared on mass sale. Before the appearance of these mice, and for a long time after that, most of the mass-produced computer “rodents” were optomechanical (the movements of the manipulator were tracked by an optical system connected to the mechanical part - two rollers responsible for tracking the movement of the mouse along the × and Y axes; these rollers, in in turn, rotated from the ball rolling when the user moves the mouse). Although there were also purely optical mouse models that required a special mouse pad for their operation. However, such devices were not encountered often, and the very idea of developing such manipulators gradually faded away.
The “type” of mass-produced optical mice familiar to us today, based on general operating principles, was “developed” in the research laboratories of the world-famous Hewlett-Packard corporation. More precisely, in its division Agilent Technologies, which only relatively recently was completely separated into a separate company within the structure of HP Corporation. Today, Agilent Technologies, Inc. - a monopolist in the market of optical sensors for mice; no other companies develop such sensors, no matter who tells you about the exclusive technologies IntelliEye or MX Optical Engine. However, enterprising Chinese have already learned to “clone” Agilent Technologies sensors, so by buying an inexpensive optical mouse, you may well become the owner of a “left-handed” sensor.
We will find out where the visible differences in the operation of the manipulators come from a little later, but for now let us begin to consider the basic principles of the operation of optical mice, or more precisely, their movement tracking systems.
How computer mice “see”
In this section, we will study the basic principles of operation of optical motion tracking systems that are used in modern mouse-type manipulators.
So, an optical computer mouse gains “vision” through the following process. Using an LED and a system of lenses that focus its light, an area of the surface under the mouse is illuminated. The light reflected from this surface, in turn, is collected by another lens and hits the receiving sensor of the microcircuit - the image processor. This chip, in turn, takes pictures of the surface under the mouse at a high frequency (kHz). Moreover, the microcircuit (let's call it an optical sensor) not only takes pictures, but also processes them itself, since it contains two key parts: the Image Acquisition System (IAS) and the integrated DSP image processing processor.
Based on the analysis of a series of consecutive images (representing a square matrix of pixels of different brightness), the integrated DSP processor calculates the resulting indicators indicating the direction of mouse movement along the × and Y axes, and transmits the results of its work externally via the serial port.
If we look at the block diagram of one of the optical sensors, we will see that the chip consists of several blocks, namely:
- the main block is, of course, ImageProcessor- image processing processor (DSP) with built-in light signal receiver (IAS);
- Voltage Regulator And Power Control- voltage regulation and energy consumption control unit (power is supplied to this unit and an additional external voltage filter is connected to it);
- Oscillator- an external signal is supplied to this chip block from a master quartz oscillator, the frequency of the incoming signal is about a couple of tens of MHz;
- Led Control- this is an LED control unit that illuminates the surface under the mouse;
- Serial Port- a block that transmits data about the direction of mouse movement outside the chip.
We will look at some details of the operation of the optical sensor chip a little further, when we get to the most advanced of modern sensors, but for now we will return to the basic principles of operation of optical systems for tracking the movement of manipulators.
It should be clarified that the optical sensor chip does not transmit information about mouse movement via the Serial Port directly to the computer. The data goes to another controller chip installed in the mouse. This second “main” chip in the device is responsible for responding to mouse button presses, scroll wheel rotation, etc. This chip, among other things, directly transmits information about the direction of mouse movement to the PC, converting data coming from the optical sensor into signals transmitted via PS/2 or USB interfaces. And the computer, using the mouse driver, based on the information received through these interfaces, moves the pointer across the monitor screen.
It was precisely because of the presence of this “second” controller microcircuit, or more precisely due to the different types of such microcircuits, that the first models of optical mice differed quite noticeably from each other. If I can’t speak too badly about expensive devices from Microsoft and Logitech (although they were not at all “sinless”), then the mass of inexpensive manipulators that appeared after them did not behave quite adequately. When these mice moved on ordinary mouse pads, the cursors on the screen made strange somersaults, jumped almost to the floor of the Desktop, and sometimes... sometimes they even went on an independent journey across the screen when the user did not touch the mouse at all. It even got to the point that the mouse could easily wake up the computer from standby mode, erroneously registering a movement when no one was actually touching the manipulator.
By the way, if you are still struggling with a similar problem, then it can be solved in one fell swoop like this: select My Computer > Properties > Hardware > Device Manager > select the installed mouse > go to its “Properties” > in the window that appears, go to the “Management” tab power supply" and uncheck the box "Allow the device to wake the computer from standby mode" (Fig. 4). After this, the mouse will no longer be able to wake up the computer from standby mode under any pretext, even if you kick it :)
So, the reason for such a striking difference in the behavior of optical mice was not at all the “bad” or “good” installed sensors, as many still think. Don't believe it, this is nothing more than a myth. Or fantasy, if you prefer :) Mice that behaved completely differently often had exactly the same optical sensor chips installed (fortunately, there were not so many models of these chips, as we will see later). However, thanks to imperfect controller chips installed in optical mice, we had the opportunity to strongly criticize the first generations of optical rodents.
However, we are somewhat distracted from the topic. Let's go back. In general, the mouse optical tracking system, in addition to the sensor chip, includes several more basic elements. The design includes a holder (Clip) in which the LED and the sensor chip itself are installed. This system of elements is attached to a printed circuit board (PCB), between which and the bottom surface of the mouse (Base Plate) a plastic element (Lens) is fixed, containing two lenses (the purpose of which was written above).
When assembled, the optical tracking element looks like the one shown above. The operating diagram of the optics of this system is presented below.
The optimal distance from the Lens element to the reflective surface under the mouse should be in the range from 2.3 to 2.5 mm. These are the recommendations of the sensor manufacturer. Here is the first reason why optical mice don’t feel good when “crawling” on plexiglass on a table, all sorts of “translucent” rugs, etc. And you shouldn’t glue “thick” legs to optical mice when the old ones fall off or wear off. Due to excessive “elevation” above the surface, the mouse can fall into a state of stupor, when “moving” the cursor after the mouse is at rest becomes quite problematic. This is not theoretical speculation, this is personal experience :)
By the way, about the problem of durability of optical mice. I remember that some of their manufacturers claimed that, they say, “they will last forever.” Yes, the reliability of the optical tracking system is high, it cannot be compared with the optomechanical one. At the same time, in optical mice there are many purely mechanical elements that are subject to wear and tear in the same way as under the dominance of the good old “opto-mechanics”. For example, the legs of my old optical mouse were worn out and fell off, the scroll wheel broke (twice, the last time irrevocably :()), the wire in the connecting cable frayed, the housing cover peeled off the manipulator... but the optical sensor works normally, as if nothing was wrong happened. Based on this, we can safely state that the rumors about the supposedly impressive durability of optical mice have not been confirmed in practice. And why, pray tell, do optical mice “live” for too long? After all, new, longer ones are constantly appearing on the market? perfect models created on a new element base. They are obviously more perfect and easier to use. Progress, you know, is a continuous thing. Let’s see what it has been like in the field of the evolution of the optical sensors that interest us.
From the history of mouse vision
Development engineers at Agilent Technologies, Inc. No wonder they eat their bread. Over the past five years, this company's optical sensors have undergone significant technological improvements and their latest models have very impressive characteristics.
But let's talk about everything in order. Microcircuits became the first mass-produced optical sensors HDNS-2000(Fig. 8). These sensors had a resolution of 400 cpi (counts per inch), that is, dots (pixels) per inch, and were designed for a maximum mouse movement speed of 12 inches/s (about 30 cm/s) with an optical sensor image rate of 1500 frames in a second. Acceptable (while maintaining stable operation of the sensor) acceleration when moving the mouse “in a jerk” for the HDNS-2000 chip is no more than 0.15 g (approximately 1.5 m/s2). 
Then optical sensor chips appeared on the market ADNS-2610 And ADNS-2620. The ADNS-2620 optical sensor already supported a programmable frequency of “capturing” the surface under the mouse, with a frequency of 1500 or 2300 images/s. Each photo was taken with a resolution of 18x18 pixels. For the sensor, the maximum operating speed of movement was still limited to 12 inches per second, but the limit on permissible acceleration increased to 0.25 g, with a frequency of “photographing” the surface of 1500 frames/s. This chip (ADNS-2620) also had only 8 legs, which made it possible to significantly reduce its size compared to the ADNS-2610 chip (16 pins), which was similar in appearance to the HDNS-2000. At Agilent Technologies, Inc. set out to “minimize” their microcircuits, wanting to make them more compact, more energy-efficient, and therefore more convenient for installation in “mobile” and wireless manipulators.
The ADNS-2610 chip, although it was a “large” analogue of the 2620, was deprived of support for the “advanced” mode of 2300 pictures/s. In addition, this option required 5V power, while the ADNS-2620 chip required only 3.3V.
Coming soon chip ADNS-2051 was a much more powerful solution than the HDNS-2000 or ADNS-2610 chips, although it was also similar in appearance (packaging). This sensor already made it possible to programmably control the “resolution” of the optical sensor, changing it from 400 to 800 cpi. The chip version also allowed for adjusting the frequency of surface images, and allowed it to be changed in a very wide range: 500, 1000, 1500, 2000 or 2300 images/s. But the size of these same pictures was only 16x16 pixels. At 1500 shots/s, the maximum permissible acceleration of the mouse during a “jerk” was still 0.15 g, the maximum possible movement speed was 14 inches/s (i.e. 35.5 cm/s). This chip was designed for a supply voltage of 5 V. 
Sensor ADNS-2030 was developed for wireless devices, and therefore had low power consumption, requiring only 3.3 V power. The chip also supported energy-saving functions, for example, the function of reducing energy consumption when the mouse is at rest (power conservation mode during times of no movement), switching to sleep mode, including when the mouse is connected via a USB interface, etc. The mouse, however, could not operate in power-saving mode: the value “1” in the Sleep bit of one of the chip’s registers made the sensor “always awake,” and the default value “0” corresponded to the operating mode of the chip when, after one second, if. the mouse did not move (more precisely, after receiving 1500 completely identical images of the surface), the sensor, together with the mouse, went into power saving mode. As for the other key characteristics of the sensor, they did not differ from those of the ADNS-2051: the same 16-pin body, movement speed up to 14 inches/s with a maximum acceleration of 0.15 g, programmable resolution 400 and 800 cpi, respectively, picture frequencies could be exactly the same as that of the above-considered version of the microcircuit.
These were the first optical sensors. Unfortunately, they were characterized by shortcomings. A big problem that arose when moving an optical mouse over surfaces, especially those with a repeating small pattern, was that the image processor would sometimes confuse separate similar areas of the monochrome image received by the sensor and incorrectly determine the direction of mouse movement.
As a result, the cursor on the screen did not move as required. The pointer on the screen even became capable of impromptu :) - unpredictable movements in any direction. In addition, it is easy to guess that if you move the mouse too quickly, the sensor could completely lose any “connection” between several subsequent images of the surface. Which gave rise to another problem: when the mouse moved too sharply, the cursor either twitched in one place, or even “supernatural” phenomena occurred, for example, with the rapid rotation of the surrounding world in toys. It was absolutely clear that for the human hand, the limitations of 12-14 inches/s on the maximum speed of mouse movement were clearly not enough. There was also no doubt that the 0.24 s (almost a quarter of a second) allocated to accelerate the mouse from 0 to 35.5 cm/s (14 inches/s - maximum speed) is a very long period of time; a person is able to move the hand much faster. And therefore, with sudden movements of the mouse in dynamic gaming applications with an optical manipulator, it can be difficult...
Agilent Technologies also understood this. The developers realized that the characteristics of the sensors needed to be radically improved. In their research, they adhered to a simple but correct axiom: the more pictures per second the sensor takes, the less likely it is that it will lose the “trace” of the mouse movement while the computer user makes sudden body movements :)
Although, as we see from the above, optical sensors have been developing, new solutions are constantly being released, but development in this area can safely be called “very gradual.” By and large, there have been no fundamental changes in the properties of the sensors. But technological progress in any field is sometimes characterized by sharp leaps. There was such a “breakthrough” in the field of creating optical sensors for mice. The advent of the ADNS-3060 optical sensor can be considered truly revolutionary!
Best of
Optical sensor ADNS-3060, in comparison with its “ancestors”, has a truly impressive set of characteristics. The use of this chip, packaged in a 20-pin package, provides optical mice with unprecedented capabilities. The permissible maximum speed of movement of the manipulator has increased to 40 inches/s (that is, almost 3 times!), i.e. reached a “signature” speed of 1 m/s. This is already very good - it is unlikely that at least one user moves the mouse at a speed exceeding this limit so often that he constantly feels discomfort from using the optical manipulator, including gaming applications. The permissible acceleration has increased, scary to say, a hundred times (!), and reached a value of 15 g (almost 150 m/s2). Now the user is given 7 hundredths of a second to accelerate the mouse from 0 to the maximum 1 m/s - I think that very few people will now be able to exceed this limitation, and even then, probably in their dreams :) The programmable speed of taking pictures of the surface with the optical sensor of the new chip model exceeds 6400 fps, i.e. "beats" the previous "record" almost three times. Moreover, the ADNS-3060 chip can itself adjust the frequency of snapshots to achieve the most optimal operating parameters, depending on the surface over which the mouse moves. The “resolution” of the optical sensor can still be 400 or 800 cpi. Let's use the ADNS-3060 chip as an example to look at the general principles of operation of optical sensor chips.
The general scheme for analyzing mouse movements has not changed compared to earlier models - micrographs of the surface under the mouse obtained by the IAS sensor block are then processed by a DSP (processor) integrated in the same chip, which determines the direction and distance of movement of the manipulator. The DSP calculates the relative magnitudes of the × and Y coordinates relative to the mouse's home position. Then the external mouse controller chip (what it is needed for, we said earlier) reads information about the movement of the manipulator from the serial port of the optical sensor chip. Then this external controller translates the received data about the direction and speed of mouse movement into signals transmitted via standard PS/2 or USB interfaces, which are then sent to the computer.
But let’s delve a little deeper into the features of the sensor. The block diagram of the ADNS-3060 chip is shown above. As we can see, its structure has not changed fundamentally, compared to its distant “ancestors”. 3.3 Power is supplied to the sensor through the Voltage Regulator And Power Control block; the same block is charged with voltage filtering functions, for which a connection to an external capacitor is used. The signal coming from an external quartz resonator to the Oscillator block (the nominal frequency of which is 24 MHz; lower-frequency master oscillators were used for previous models of microcircuits) serves to synchronize all computational processes occurring inside the optical sensor chip. For example, the frequency of images of an optical sensor is tied to the frequency of this external generator (by the way, the latter is not subject to very strict restrictions on permissible deviations from the nominal frequency - up to +/- 1 MHz). Depending on the value entered at a specific address (register) of the chip’s memory, the following operating frequencies for taking pictures with the ADNS-3060 sensor are possible.
| Register value, hexadecimal | Decimal value | Sensor snapshot rate, frames/s |
| OE7E | 3710 | 6469 |
| 12C0 | 4800 | 5000 |
| 1F40 | 8000 | 3000 |
| 2EE0 | 12000 | 2000 |
| 3E80 | 16000 | 1500 |
| BB80 | 48000 | 500 |
As you might guess, based on the data in the table, the frequency of sensor snapshots is determined using a simple formula: Frame rate = (Setting generator frequency (24 MHz)/Value of the register responsible for the frame rate).
Surface images (frames) taken by the ADNS-3060 sensor have a resolution of 30x30 and represent the same matrix of pixels, the color of each of which is encoded with 8 bits, i.e. one byte (corresponding to 256 shades of gray for each pixel). Thus, each frame (frame) arriving at the DSP processor is a sequence of 900 bytes of data. But the “cunning” processor does not process these 900 bytes of the frame immediately upon arrival; it waits until 1536 bytes of information about pixels are accumulated in the corresponding buffer (memory) (that is, information about another 2/3 of the subsequent frame is added). And only after this the chip begins to analyze information about the movement of the manipulator, by comparing changes in successive images of the surface.
With a resolution of 400 or 800 pixels per inch, their implementation is indicated in the RES bit of the microcontroller memory registers. A zero value of this bit corresponds to 400 cpi, and a logical one in RES sets the sensor to 800 cpi mode.
After the integrated DSP processor processes the image data, it calculates the relative displacement values of the manipulator along the × and Y axes, storing specific data about this in the memory of the ADNS-3060 chip. In turn, the external controller (mouse) chip, via Serial Port, can “draw” this information from the memory of the optical sensor approximately once every millisecond. Note that only an external microcontroller can initiate the transfer of such data; the optical sensor itself never initiates such a transfer. Therefore, the issue of efficiency (frequency) of tracking mouse movement largely lies on the “shoulders” of the external controller chip. Data from the optical sensor is transmitted in 56-bit packets.
Well, the Led Control block with which the sensor is equipped is responsible for controlling the backlight diode - by changing the value of bit 6 (LED_MODE) at address 0x0a, the optosensor microprocessor can switch the LED to two operating modes: logical “0” corresponds to the “diode is always on” state, logical “1” switches the diode to the “on only when necessary” mode. This is important, say, when operating wireless mice, as it allows you to save the power of their autonomous power supplies. In addition, the diode itself can have several brightness modes.
This, in fact, is all about the basic principles of operation of an optical sensor. What else can you add? The recommended operating temperature of the ADNS-3060 chip, as well as all other chips of this kind, is from 0 0C to +40 0C. Although Agilent Technologies guarantees the preservation of the operating properties of its chips in the temperature range from -40 to +85 ° C.
Laser future?
Recently, the Internet was filled with praising articles about the Logitech MX1000 Laser Cordless Mouse, which used an infrared laser to illuminate the surface under the mouse. Almost a revolution in the field of optical mice was promised. Alas, having personally used this mouse, I was convinced that the revolution did not happen. But that's not what this is about.
I haven’t disassembled the Logitech MX1000 mouse (I didn’t have the opportunity), but I’m sure that behind the “new revolutionary laser technology” is our old friend - the ADNS-3060 sensor. Because, according to the information I have, the sensor characteristics of this mouse are no different from those of, say, the Logitech MX510 model. All the “hype” arose around the claim on the Logitech website that using a laser optical tracking system, twenty times (!) more details are detected than using LED technology. On this basis, even some respected sites have published photographs of certain surfaces, they say, how ordinary LED and laser mice see them :) 
Of course, these photos (and thank you for that) were not the multi-colored bright flowers with which the Logitech website tried to convince us of the superiority of the laser illumination of the optical tracking system. No, of course, optical mice did not begin to “see” anything similar to the given color photographs with varying degrees of detail - the sensors still “photograph” nothing more than a square matrix of gray pixels, differing from each other only in different brightness (processing information about extended color palette of pixels would place an enormous burden on the DSP).
Let's estimate that to get a 20 times more detailed picture, you need, excuse the tautology, twenty times more details, which can only be conveyed by additional pixels of the image, and nothing else. It is known that the Logitech MX 1000 Laser Cordless Mouse takes pictures of 30x30 pixels and has a maximum resolution of 800 cpi. Consequently, there can be no talk of any twenty-fold increase in the detail of images. Where did the dog go rummaging :), and aren’t such statements generally unfounded? Let's try to figure out what caused this kind of information to appear.
As is known, a laser emits a narrowly directed (with small divergence) beam of light. Consequently, the illumination of the surface under the mouse when using a laser is much better than when using an LED. A laser operating in the infrared range was chosen, probably, so as not to dazzle the eyes due to the possible reflection of light from under the mouse in the visible spectrum. The fact that the optical sensor works normally in the infrared range should not be surprising - from the red range of the spectrum, in which most LED optical mice operate, to the infrared - “at your fingertips”, and it is unlikely that the transition to a new optical range was difficult for the sensor. For example, the Logitech MediaPlay controller uses an LED, but also provides infrared illumination. Current sensors work without problems even with blue light (there are manipulators with such illumination), so the spectrum of the illumination area is not a problem for sensors. So, due to the stronger illumination of the surface under the mouse, we have the right to assume that the difference between the places that absorb radiation (dark) and reflect the rays (light) will be more significant than when using a conventional LED - i.e. the image will be more contrasty.
And indeed, if we look at real photographs of a surface taken by a conventional LED optical system and a system using a laser, we will see that the “laser” version is much more contrasty - the differences between the dark and bright areas of the image are more significant. Of course, this can significantly facilitate the work of the optical sensor and, perhaps, the future lies with mice with a laser backlight system. But such “laser” images can hardly be called twenty times more detailed. So this is another “newborn” myth.
What will the optical sensors of the near future be like? It's hard to say. They will probably switch to laser illumination, and there are already rumors on the Internet about a sensor being developed with a “resolution” of 1600 cpi. We can only wait.
Computer mouse- Probably everyone knows what it is. This is a manipulator or a coordinate input device for controlling the cursor and issuing various commands to the computer. Over time, this device develops various malfunctions: damage to the stranded wire, the sensor often malfunctions, the mouse wheel sometimes scrolls, mouse buttons do not work, etc.
Let's look at do-it-yourself repair of the most popular computer pointing device - the mouse!
The mouse is technically a fairly simple device, so it can be quite easily repaired with your own hands. If you know how to handle a soldering iron even a little, this will allow you to fix almost any damage to the mouse. However, even if you are not comfortable with a soldering iron, you can fix some typical mouse damage with a minimum set of tools:
- crosshead screwdriver,
- pliers,
- scissors,
- scotch.
Basic malfunctions of computer mice
Now there are several types of computer mice that differ in the principle of operation (roller, optical or laser), the number of buttons (3 and above), and the type of connection (PS/2, USB or wireless (with USB adapter)). However, the most common are optical ones with a USB or PS/2 connection.
Such mice are relatively inexpensive (not much more expensive than roller mice, but much cheaper than laser ones) and at the same time have fairly high accuracy, which is enough for most users.
| Np.p. |
Description of the problem |
Possible malfunction |
|---|---|---|
| 1 | The mouse does not respond to connection at all | Broken or chafed wires; violation of the integrity of the printed circuit board; controller failure |
| 2 | The sensor is acting up. The cursor jumps or moves jerkily | Optical sensor clogged; LED fault |
| 3 | The scroll wheel does not work or the scrolling area moves jerkily when scrolling | Loosening of the scroll mechanism; drying of the lubricant inside the mechanism; encoder defects (scroll sensor) |
| 4 | A specific button gets stuck or double pressed | Loosening; failure of the button mechanism; problem with settings or mouse driver |
| 5 | A specific mouse button does not work | Failure of the button mechanism |
Disassembly and device of the mouse
We usually disassemble the mouse using a small Phillips screwdriver. To do this, turn the mouse upside down, find and unscrew one or more screws that hold it together. If the screws are not visible, then they are most often hidden under stickers or foot stands:
Usually the screws only hold the mouse in the back. The front part (where the buttons are), most often, is fixed due to special grooves. To remove the top cover from these grooves, you need to lift it slightly by the freed back part and slowly pull it towards you. You can press it a little more from the front, but the main thing is not too hard, otherwise you will break it! The grooves on the top cover of the mouse and the pins that held them in place:
When you remove the top cover, you will find a small circuit board underneath, which is usually only held in place by small plastic pins (although it can also be screwed to the case). Wires (if the mouse is wired), buttons, a scrolling mechanism, as well as a complex of LED backlight and sensitive optical sensor will be soldered to this board:
To completely disassemble the mouse, we need to remove the printed circuit board from it and disconnect the scroll wheel (it can be easily pulled out of the encoder slots).
Wire inspection and repair
Most often, when connected to a computer, the mouse either does not work at all, or twitches or the cursor movement disappears if one of its wires frays or breaks somewhere (unless, of course, the mouse is wired).
A typical optical mouse usually has 4 to 6 wires of different colors. The colors and number of wires depend on the specific manufacturer, however, there is a standard:
Mouse wiring color scheme
Nutrition– red (other options: golden, orange, blue, white).
Receiving data– white (other options: blue, orange, yellow, green).
Data transfer– green (other options: golden blue, yellow, red, blue).
Earth– black (other options: golden green, green, white, blue).
You can definitely judge the correct wiring by looking at the letter markings of the wires in the place where they are soldered to the printed circuit board (unless, of course, they are torn off from the board). Breakage and chafing of wires most often occurs in places where the wire is bent at the exit from the mouse body. You can indirectly check for a break by pulling out the wire and testing it for bending in questionable places (it will be easier to bend at the break point). However, in order to judge for sure, you will have to remove the insulation by carefully cutting it with a blade.
Having discovered a place where the wiring is broken, you need to restore its integrity by soldering or twisting. I personally prefer twisting :) I’ll give a photo of the finished twist, how it should look:
After splicing the wires, insulate them from each other with electrical tape or tape. You can try it. To avoid burning the port, you need to connect or disconnect the mouse when the computer is turned off! To eliminate any doubts about a break, try ringing all the contacts of the USB (or PS/2) plug using a multimeter. After repair, the mouse should work.
Optical mouse sensor does not work
Often there is also a situation when we cannot accurately move the cursor to a certain point. It constantly trembles and moves on its own. This situation clearly indicates that the optical group of the mouse is clogged. Clogging is most often external. Dust or hair gets into the compartment where the diode light is reflected from the table.
To get rid of such a blockage, you don’t even need to disassemble the mouse. Just turn it over and blow it out. As a last resort, use a small brush to remove stuck debris.
If even after such manipulations the mouse cursor trembles, then, most likely, either the sensor is clogged inside or has completely failed.
In any case, you can try to disassemble the mouse and clean the sensor using a toothpick with a cotton swab soaked in alcohol wrapped around it:
Optical sensor of a computer mouse
Before cleaning the sensor with a cotton swab, you can also try blowing it to remove any fine dust that may stick after it gets wet. After this, carefully, without pressing, insert the toothpick with rotational movements into the sensor hole. After making a couple of turns and without stopping rotating, we take out the toothpick, wait for the alcohol to dry and try to connect the mouse.
If, after all attempts at cleaning, the sensor does not work normally, then if you have another mouse, a soldering iron and straight hands, you can unsolder the non-working microcircuit and replace it with a sensor from another mouse.
Mouse wheel scrolls
It happens that the mouse works fine, but when we try to use its wheel, the page we are scrolling begins to jump up and down, or does not want to scroll at all. Alas, failure of the mouse wheel is a fairly common failure and it was this that prompted me to write this article. First you need to carefully consider how evenly the wheel rotates in the groove. The groove itself and the wheel axle have a hexagonal cross-section, but sometimes one or more sides of this hexagon can become deformed, resulting in the axle slipping in the problem area.
If you have just such a problem, then it can be solved by sealing the edge of the wheel axle with adhesive tape or electrical tape in small quantities. If everything is normal with the movement of the wheel, then the breakdown has occurred inside the encoder (scroll sensor). It may have become loose from prolonged use and should be tightened a little:
We tighten the latches of the mouse scroll mechanism
To do this, take small pliers and press them one by one on the four metal brackets that secure the encoder to the plastic parts of the scroll mechanism. The main thing here is not to overdo it and not break the fragile plastic, but at the same time press harder. Try connecting the mouse and checking whether the negative effect when scrolling decreases after each click. Alas, in my case it was not possible to completely get rid of jerks. Yes, the frequency and spread of page jumps have decreased, but the jumps themselves have not completely disappeared. Then I decided to approach the issue of sealing radically and in a truly Russian way :) I cut out a piece of thin but dense polyethylene from an old battery pack and stuck it inside the mechanism:
Seal inserted inside the mouse scroll mechanism
What’s most interesting is that this manipulation helped! All I have to do is cut off the excess length of the strip and assemble the mouse :)
There are several more options:
- disassemble and clean the mechanism;
- replace the mechanism from another mouse (with a different malfunction).
Mouse buttons don't work
Any button has its own click resource. Usually the contact at the left mouse button disappears. The mouse has several buttons: left, right and under the wheel. They are all usually the same. A non-working button cannot be repaired in any way, but it can be replaced from another mouse.
Bottom view of a soldered mouse button microswitch
The microswitch has three “legs”, the first of which is free, and the other two are contacts that need to be soldered. Sometimes the button still works, but it doesn’t work every time you press it. Such a symptom may indicate that, from frequent use, the edge of the button pusher that presses the microswitch has worn out or there is poor contact inside the contact plate switch.
We disassemble the mouse and carefully examine the problematic button and its pusher. If we see a small dent, then that may be the problem. It is enough to fill the dented area with a drop of epoxy resin or melted plastic. At the same time, while the switch is disassembled, you can clean the contact group.
The last problem you may encounter is that the mouse button makes a double click when you click on it - the so-called contact bounce. This issue can be solved by re-soldering the microswitch or... programmatically!
In any case, before you take up the soldering iron, check that the mouse settings are correct in the Windows Control Panel:
Standard mouse properties, what they should be
By default, the double-click speed slider should be in the center, and the sticky mouse buttons option should be disabled. Try setting these parameters and check if the problem is resolved. If not, another radical software way to “cure” a double click is to remove the mouse driver.
Mice– one of the most actively used computer devices. Therefore, it is not surprising that they often fail. However, due to the simplicity of their design, in most cases anyone can fix a mouse! To do this, you don’t need to know how to solder or understand electronics.
The so-called “mice” are an integral part of a modern computer. With the advent of new ones, old ones that are still functional, but morally obsolete, as a rule, are thrown away or gather dust idle in the pantry. However, they can be used without practically changing the electronic filling. This is not difficult to do.
"RED EYE" TURN ON THE LIGHTS
Today you won’t surprise anyone with original light switches, but the one presented below - an optical computer mouse, in my opinion, is unusual and convenient in a city apartment for several reasons:
Firstly, the miniature mouse fits well into the slot under the standard key switch on the wall;
- secondly, direct contact with the switch is not required - just hold your finger (or other object) at a distance of 1.5 cm from the “red eye” of the backlight;
- thirdly, the device initially has a trigger effect: swipe your finger once - the light comes on, swipe a second time - it turns off;
- a response indicator is also provided - when you move your finger near the “backlight”, it lights up three times brighter.
A simple current amplifier on a transistor with an executive relay in the collector circuit is added to an optical computer mouse so that the signals from the mouse control a lighting lamp with a power of up to 200 W (limited by the relay parameters) - more on this below. Since almost all computer optical mice are built according to the same design and principle of operation, let’s consider one of them - Defender Optical 1330, shown in photo 1.
Photo 1. View of the Defender Optical 1330 optical mouse with the housing cover removed
Photo 2. Printed circuit board of the Defender Optical 1330 optical mouse from the optical lens side
Photo 3. RX-9 transceiver of a set of wireless keyboard and optical mouse manipulator
Photo 4. Installing a wireless mouse to protect a safe
Photo 5. Siren KPS-4519 as an audible alarm
The main coordinate positioning device is a microassembly with the designation U2 A2051B0323, combined with a photodetector (in one housing). From pin 6 of this microassembly, pulses with a frequency of about 1 kHz are constantly sent to the red LED, so even when the optical mouse is motionless on the table, a red, barely flickering “backlight” is visible. However, its significance is not only to highlight the place occupied by the mouse - for beauty. The LED is a transmitter, and the receiver is the microassembly itself with an electronic unit built into its body. When light signals reflected from any surface reach the photodetector, the voltage level at pin 6 of U2 drops to zero and the LED lights up at full power. This is exactly the reaction we see in a mouse on a computer desk when we try to move it.
The LED's full burning time is 1.3 s (if there are no longer impacts on the mouse). One of the main parts of an optical mouse, oddly enough, is not electronics, but a plastic lens, curved to a certain radius (see photo 2), without it the mouse will “go blind”.
The mouse must be installed in a wall niche under a standard switch in an assembled case that reliably fixes the optical lens on the side of the base (substrate) of the mouse.
When a signal reflected from an obstacle (your finger, palm) is received at the photodetector, the logical signal level changes to the opposite at pins 15 and 16 of the U1 microassembly HT82M398A (and, accordingly, at pins 4 and 5 of the U2 microassembly). Moreover, these are not inverse conclusions, but independent of each other. The signal on them changes depending on the vertical or horizontal movement of the mouse. The control signal for the actuator (low level changes to high, pin 15 U1 and pin 4 U2) is connected to the actuator, to point A.
The transistor opens and the relay turns on at a high logical level at point A. Diode VD1 protects the relay winding from reverse current surges. Resistor R1 limits the current in the base of the transistor. The relay can control not only a lighting lamp, but also any load with a current of up to 3 A. The power source is stabilized, with a voltage of 5 V ±20%. The transistor can be replaced with KT603, KT940, KT972 with any letter index, and the executive relay K1 can be replaced with RMK-11105, TRU-5VDC-SB-SL or similar with an operating voltage of 4-5 V.
Rice. 1. Current amplifier with an executive relay that controls the load in a 220 V network
Rice. 2. Adapter diagram for sound alarm for opening a safe
The four-wire cable is partially unsoldered from the board at the junction with the standard connector and two wires are soldered (green and white to pins 15 and 16 of the U1 microassembly from the elements (not printed circuit) side), since otherwise the wires will interfere with installation of the board into the mouse body.
Initial wiring of the connector on the mouse board: 1st pin - common wire, 2nd pin - "+5 V" power supply, 3rd and 4th - output pulses.
If the circuit and printed circuit board of your mouse do not correspond to the one shown in the Defender Optical 1330 example, it is enough to take any oscilloscope or logic probe (indicating at least two main states - high and low) and empirically find points on the board with a control signal.
Any optical mouse for a PC will do, so it doesn’t matter which connector is at the end of the computer mouse connecting cable, it will still have to be removed. You can also use wireless mice (with signal transmission via a radio channel, for example, from the A4 TECH kit - RX-9 5 V 180 mA mouse adapter), in terms of coordinate positioning, they have the same operating principle as wired ones.
MOUSE-WATCHMAN
Now there is a new wave of generational change in a common computer pointing device: “tailed” (with wires) optical mice are giving way to their wireless counterparts. For example, the RP-650Z wireless optical manipulator mice, complete with a wireless keyboard (with an ergonomic arrangement of the main keys and 19 additional reprogrammable buttons), are relevant. The Agilent Technologies sensor used in the RP-650Z mouse is a leader in this market sector.
The optical resolution of the mouse is 800 dpi - this is quite enough for good work. The radio signal transceiver and AA battery charger with a switch for fast charging are located in one housing (photo 3). This unit connects to a USB port.
A4Tech company marks its manipulators with an individual electronic code, thanks to which up to 256 manipulators or keyboards can coexist on one reception channel. Such a technical solution narrows the data transmission bandwidth, but with a maximum reliable reception radius of 2 meters, this is not critical.
An unusual option for using a wireless mouse - as a signal for opening a safe, operating a washing machine, and even... a refrigerator is presented below. All of these options are based on micro-displacement of the object and even on the detonation effect. When you install the mouse on a metal door, you will get an alarm for its opening or impact (another application option).
I should note that a no less effective signaling device can be obtained if a car shock sensor is installed as a mouse on the controlled surface; it is also triggered by detonation or mechanical impact on the controlled surface, and its modern models even have several levels of sensitivity adjustment. A computer mouse does not have this option, by definition, its first and main purpose, but this is not important; after all, we are considering its unusual application.
I installed a wireless mouse RP-650Z (from A4Tes11) on the front wall of the safe in which hunting weapons are stored, although you can store anything in it (photo 4).
The safe is in the built-in closet (a niche in the wall of a city apartment); Thanks to wireless technology, there is no need for wires. Within 2 meters there is a radio signal transceiver (see photo 3), which is connected to an adapter device (diagram in Fig. 2).
The wiring of the connector for the USB port is no different compared to the option considered above. In the RP-650Z wireless mouse, the control signal (when the mouse is moved, the level in this model changes from high to low) is taken from pin 4 of the only microassembly UM1 (designation on the board). Therefore, in this case, a different current amplifier circuit will be required (see Fig. 2). Now, when opening the safe or even any mechanical impact on it (displacing the mouse sensor by a fraction of a millimeter), the security device will be triggered.
A sound capsule with a built-in audio frequency generator is used as HA1; it must be connected strictly in accordance with the polarity. Transistor VT1 of pnp conductivity opens when the voltage at point A is close to zero, that is, at the moment the mouse is displaced. You can also use the KPS-4519 siren (photo 5), since with a 12 V power supply it produces sufficient sound volume to be heard in neighboring rooms (more than 80 dB). The siren must be connected in accordance with the polarity (red wire - to the “+” power supply).
Two words about securing the mouse. A magnet (from advertising refrigerator magnets) is glued to the lower part of its body, without covering the LED and lens. Now the mouse is securely fixed on any metal surface (refrigerator, washing machine, etc.). When you try to remove it, an alarm will also go off, informing the owner about unauthorized access to the safe.
Thanks to “wireless”, the user has the opportunity to install the mouse as desired, moving it away from the receiver at a reasonable distance, without worrying about connecting wires. There can be as many options for using this technology as you like, and they are limited only by your imagination.
Types of computer mice. There are all sorts of computer mice. Such diversity can even make your head spin. But just recently there was practically no choice. It would seem, what else can you come up with? But it turns out it is possible. Each company that produces these small and so necessary “animals” finds more and more new designs and functions for them.
Which There are types of computer mice?
There are just not that many species. Here they are:
- Mechanical or ball (almost no longer used);
- Optical;
- Laser;
- Trackball mice.
- Induction;
- Gyroscopic.
Mechanical or ball mice
Mechanical or ball mice can only be found among collectors. Although just seven years ago it was the only species. It was not very comfortable to work with it, but not having any other types, we thought it was a super mouse.
She was a bit heavy in weight and didn’t want to work without a mat. And her positioning left much to be desired. This was especially noticeable in graphics programs and games. And I had to clean it very often. What didn't fit under this ball? And if there were still animals living at home, then this process was repeated at least once a week.
I always had tweezers near my computer, because... my furry friends always tried to sleep near the computer, and their fluff clung to the rug, making it shaggy. Now I no longer have such a problem. The ball-shaped “rodent” was replaced by a more modern mouse – an optical one.
Optical LED mouse
Optical LED mouse - it works on a different principle. It uses an LED and a sensor. It already works like a small camera that scans the surface of the table with its LED and photographs it. An optical mouse can take about a thousand such photos per second, and some types even more.
The data from these images is processed by a special microprocessor and sends a signal to the computer. The advantages of such a mouse are obvious. It doesn't require a mat, is very light in weight and can easily scan almost any surface.
Optical laser mouse
Optical laser mouse - very similar to optical, but its operating principle differs in that instead of a camera with an LED, a laser is already used. That’s why it’s called laser.
This is a more advanced model of an optical mouse. It requires much less energy. The accuracy of reading data from the working surface is much higher than that of an optical mouse. It can even work on glass and mirror surfaces.
Trackball mouse
Trackball mouse – a device that uses a convex ball (trackball). The trackball is an inverted ball mouse. The ball is on top or side. It can be rotated with your palm or fingers, and the device itself remains in place. The ball causes a pair of rollers to rotate. New trackballs use optical motion sensors.
