A simple burglar alarm based on a cell phone. Making a GSM alarm with your own hands from your phone
Hello Lifehackers! We continue to broadcast interesting topics from the weekly electronic magazine. In the magazine we write about useful gadgets, amazing inventions, look a little into the future, and also give advice of varying degrees of usefulness. Subscribe to the magazine and read the entire content, but first read the tip on how to make an alarm out of an old phone. For example, automobile.
In a modern city, and not only in the city, very often you have to leave your car unattended in unguarded parking lots, or simply on the street out of sight. In this case, even if the standard alarm goes off when the car is opened by an intruder, you will not hear it.
It would be great if a car, when you try to steal it, would call your cell phone!
Why not! You just need to teach your car to use a mobile phone.
Let's do this with step-by-step instructions.
Surely you have an old mobile phone, or even two, lying around somewhere in a pile of junk.
Step 1
We take a phone that has a speed dial function (this condition is mandatory).
Step 2
Let's disassemble the phone. We cut a hole on the keyboard above the button with the number “2” and solder two wires to the contact pads of this button (to simulate pressing the button when the wires are shorted). We collect the phone.
Step 3
We connect the battery to the phone using a pair of wires, observing the polarity. In parallel, we solder the output of the car charger.
Step 4
We buy a new SIM card and install it in the phone.
Step 5
We write down your mobile phone number, activating its speed dialing in the car phone. In the car phone settings, turn off the ringer and indication.
Step 6
We connect the charger to the car battery using two wires, observing the polarity.
Step 7
We connect the wires coming from the button through the additional switch to the driver's door limit switch (the additional switch is needed to quickly disable the security function).
So, the alarm is ready!
When you open the door, a call will immediately come to your mobile phone, and you will realize that someone has climbed into the car. In addition, you can determine its location using the signal from your car phone.
Such alarms can work not only on cars, but also on any other objects, such as cottages, garages, etc. You just need to consider where to power the device.
However, not in all cases an alarm system can help.
What would you use an alarm like this for? It can also be used as an information system that rings, for example, when someone opens the refrigerator door.
We welcome comments and ideas for protected objects, even the most crazy ones.
We also recommend reading in our magazine about a minicomputer for $25 and what it can do, about a massage pen, and about which phones behave in cold weather.
It will be even easier to go straight to our magazine and not miss anything.
Good evening, dear friends! Another weekend has arrived, which means you can relax or make something out of a pile of used household appliances. I’m sitting on the social network VKontakte, scrolling through the page, but my thoughts are completely different, I’m thinking about what useful things can be made. And then suddenly my gaze fell on my cell phone. I remembered that I had an old cell phone lying around in my bins that worked, but the model was outdated and there was no longer a need for it. Without thinking for a long time, I came up with an idea to make an alarm out of it via a GSM channel. So let's get started.
First you need to find an old cell phone that you don’t mind taking apart and “spoiling” a little. I personally had the Siemens S65 model on hand. The old, good, reliable model was, in principle, and remains so now :-) Your phone should have a speed dialing function (well, when, for example, you press key 2, your saved subscriber under this key is called).
I disassembled it without any problems, since I had a set of these screwdrivers for a long time. We will need a green keyboard board.
This is what it looks like from the side where the buttons are pressed. We find key 2 (personally, you can use any of the numbers) and remove the round metal plate on it.
When the metal plate is removed, your result should look like mine. These are the contacts that closed when key number 2 was pressed.
Now we take a soldering iron and carefully solder two wires there, one wire to the central point, and a second wire to the ring. Take a thin wire, otherwise the case will not close later. Now we put everything back in place, all parts of the phone should be where they were before disassembling the phone.
That's it, we have the phone assembled, but two wires are sticking out, we clean them out. Now we take an additional SIM card and install it in this phone. I want to say that if the SIM card is new, it will be even better, since no one will call this number and unnecessary messages will not come either (in particular, any advertisements from short numbers). After this, we save your personal number under key 2 as a speed dial, and in your personal phone the number of this SIM card that you inserted into this modernized telephone with wiring, for example, under the name “Car Security”. On the same phone, you can turn off the screen backlight, be sure to turn off vibration and ringing. That's it, now you close the two wires and wait for a call from the alarm system of this phone to come to your phone. Thus, you can listen to what is happening where this upgraded phone is installed, for example, the conversation of robbers. I have a reed switch at the end of the wires (this is a glass tube, there are contacts inside it, the contacts are activated when a magnet is brought to it). They are available in radio stores, but instead of them, you can install a regular microswitch with open contacts. Their number is not limited; you can install as many switches as there are protected doors, for example in a car or in a country house.
Well, I forgot to say, if the phone is very old, then always leave it on charge, this will give you more guarantee that the battery will not run out. Well, that's all I wanted to tell you today. This article will be improved and become more complex, so to begin with, I started with something simple, so that even those who have never picked up a soldering iron, much less disassembled household appliances, could assemble it. Collect, try, experiment, and share what you get out of it :-) See you again, Dear friends! Thank you for your attention!
P.S. I even made a short video of how it works.
If you have an old mobile phone with buttons lying around at home, then do not rush to throw it away.
In this article I will describe how you can make a mobile alarm from an old push-button mobile phone.
Where to start making?
First we need to configure the phone itself. In the phone settings, turn off all kinds of sounds and lights.We turn off the auto-lock of the phone and put a speed dial number on button 2.
To assemble our mechanism, we will need ordinary things that are found in every home.
Materials:
1. Nail - it should be slightly longer than the phone itself, about 1.5 cm.
2. Mounting dowel - into which the nail fits without play but easily.
3. Squeeze spring - approximately 1.5 cm long.
4. Rubber band - To hold down the speed dial button.
5. Clothespin - we will use it to make a nail lifter.
6. And of course the mobile phone itself.
Alarm assembly instructions
1. First of all, cut the dowel into three parts.The first part is to cut off the cap from the dowel about 1 cm long.
The second part - cut off part of the dowel about 2-2.5 cm long.
Third part - cut off part of the dowel about 0.5 cm long.
2. We clean the nail from irregularities and nicks with a regular needle file so that it can easily slide inside the cut out parts of the dowel.
3. Glue the parts of the dowel to the phone; for convenience, we use the same nail to glue them in one direction.
For convenience, I also used hot-melt glue as it quickly glues and dries, but you can use other suitable glue.
- Glue the smallest part onto the button.
- We glue the largest part at the top of the phone above the screen, use a nail to guide both parts and glue them along the same axis.
4. We put a dowel cap on the nail, and then a release spring, lubricate it with a drop of mechanical oil and insert the nail into the glued parts of the dowel on the phone. Thus, we have a primitive button that will play the main role of an alarm.
5. Cut off the tip of the clothespin and wipe the lifting path in the middle with a file or nail.
6. Glue this lift at the very bottom of the phone under the “0” button so that the tip of the nail barely touches the lift and is directed towards the lifting path.
7. We wrap a rubber band around the phone and a nail 4-5 turns opposite the “2” button so that it (the “2” button) is constantly pressed.
That's all, now when we press the primitive button of our mechanism, button “2” leaves the pressed state and nothing happens, but when we release the button of our primitive mechanism, button “2” will again be in the pressed state, thereby dialing the number
Installation
With the door closed, lightly pressing the button, glue the alarm at the top of the door with double-sided tape.
I hope you liked this homemade product. Thank you for your attention!
Cellular communications, and of course cell phones, have entered our lives a long time ago and forever! They have become everything we can, not only as a means of communication, but also as navigators, information directories, and mobile media complexes. In addition, a cell phone can also be used as a means of notification when at a sensitive facility, that is, calling the subscriber when the alarm sensor is triggered. Thus, the phone itself becomes part of this very alarm system. This is exactly the kind of DIY mobile phone alarm that we will talk about in our article.
What will be needed for a mobile phone alarm?
For signaling from a mobile phone, we first need this same mobile phone. In this case, an important circumstance will be the fact that the phone must have a “fast call” and dial the number we need with one click. That is, they pressed, and at the same time the phone should exit the standby mode and also dial the number. All other options are not suitable for us! Let’s say right away that such phones exist and can be found, you just have to look for them! In our case it is Samsung GT-E1080. In fact, this is not a dogma at all. As we said, the main thing here is to click and call.
In addition, we will need a 220 volt motion sensor. A regular phone charger will be required. You will need a small 5 volt power supply. Relay for switching button contacts at 5 volts. LEDs for indication. A housing, in our case a junction box and a couple of toggle switches and wires for soldering.
How to make a mobile phone alarm with your own hands
Now directly about the alarm assembly process itself. Oddly enough, you don’t need to know anything special here, we’re talking about knowledge in electronics, because such an alarm system is already assembled from ready-made blocks that we listed above. In fact, you provide power to all units and connect the relay and motion sensor. See the diagram.
That is, all power supplies are connected to 220 volts. At the same time, the standard charger powers the phone. When triggered, the motion sensor sends a signal to the 5 volt power supply. The power supply turns on the relay. The relay closes for the duration of the sensor response. This is about 30 seconds. This time is quite enough for the closed contacts of the telephone button, which are switched by the relay itself, to force the telephone to make a “speed dial” to a pre-entered number. Here you will need to connect the wires to the keyboard button that contains this very number. That is your number. A call to the phone will mean that the motion sensor has been triggered, which means the alarm has been activated.
Features of this mobile phone alarm
We believe that the peculiarity of this alarm is that it works with a 220-volt motion sensor. Typically, 5-volt motion sensors, such as those for Arduino, are used for such purposes. The disadvantages of this solution are a more expensive sensor and the use of a power supply to turn on the relay. And the advantages include the versatility of using the sensor, the presence of a housing on it, which will allow you to mount it on a wall or ceiling. The ability to connect a powerful siren, at least 220 volts, at least 5 volts. It depends on where you make the connection, before or after the 5 volt power supply. Another advantage is the implementation of switching using a relay, and not a transistor, as many solutions offer. In this case, the circuits of the phone and the motion sensor are completely electrically isolated and ultimately do not affect each other. This will not lead to spontaneous activation of the sensor, and will not damage the phone since external potential will never reach its key contacts. In general, as always, they bring their own disadvantages and their advantages.
Summing up and a video about how an alarm system works from a mobile phone assembled with your own hands
You can use such an alarm system for your home, garage, or anything else. In all these cases, she will cope with her tasks perfectly. The only thing is that when installing an alarm system, we would advise you to connect it to an uninterruptible power supply. This will allow the alarm to go off even if the attackers disconnect the protected object from the voltage. Another recommendation would be to install an alarm in a simple metal box. Like those used to install meters. This is necessary so that the alarm has time to complete its call before it is neutralized by criminals. That's all! As you can see, most of you can set up an alarm on your mobile phone. This does not require any special knowledge or skills!
Video on how to make a cell phone alarm with your own hands
In this article we will show four schemes with notification via a mobile phone. Security device, fire alarm, car alarm and anti-theft system controlled via telephone.
Four schemes with notification via mobile phone:
1. A simple circuit of a “short-circuit” security device;
2. Security and fire alarm system “on break”;
3. Car security alarm;
4. Anti-theft system controlled via telephone.
The article discusses simple ways to use a mobile phone as part of security systems as a detector, and even a control device, which allows you not only to notify you of attempts to steal your property, but also to prevent the theft of your car.
A mobile phone can be successfully used as a detector for a security device that will notify you about the safety of your valuables. For example, when connected to a car alarm system, the cell phone will notify you when the alarm is triggered. Such warning devices were popular in the 90s among radio amateurs, but they included an amateur radio transmitter - usually 27 MHz. But we don’t stand still! Why do we need to carry a security radio with us? The cell phone notification device described below is much simpler and more profitable than using radio transmitters and radio receivers, because the cell phone is not taken with you only to the steam room and when swimming in the pool or sea. And then, there is no limit to the resourcefulness of the Russian person.
Any push-button cell phone has the function of “quick calling” a subscriber with one button. This is what we will use. But before that, you need to configure your phone. It is necessary, by entering the phone menu, to enter into the quick call memory the cell phone number to which you will need to call when the state of the controlled object changes.
It is necessary to modify the phone: Carefully open the keyboard panel of the cell phone and, using a miniature soldering iron, solder two conductors of thin mounting wire in insulation to the contacts of the key (for example, the “1” button). Other keys, or even several buttons, can be used to notify, for example, different subscribers in dissimilar, different situations. Conductors must have a minimum length (no more than 1 m). It is better if the conductors are placed in a screen that is connected to ground (minus power).
We've familiarized ourselves with the modifications to the phone, now let's move on to specific diagrams of security devices.
A simple circuit of a “closed circuit” security device
Let's start with the simplest thing - security of the premises. In the first scheme, you can use, for example, reed switches installed to open doors, windows, etc. as sensors. When the latter are opened, the contacts of the reed switches are closed, including a shortcut button. The diagram is shown in the figure.
Elements R1, R2 and C1 are an integrating chain that acts as a filter that suppresses high-frequency interference and interference. To be effective, they, unlike reed switches, should be located in close proximity to the telephone. To eliminate false operation from mains voltage interference, it is necessary to use shielded wires going to the reed switches. The best option is if it is shielded twisted pair. The screen must be connected directly to the negative power supply of the mobile phone. To ensure constant operation of the security device, regardless of the battery charge of the mobile phone, it is a good idea to provide constant power to the phone through a standard power adapter via a 220 volt network. The advantage of the above scheme is its maximum simplicity. The reed switches must be normally open and work like this: the door is closed - the reed switch is open, the door is open - the reed switch is closed. Instead of reed switches, ordinary microswitches can be used.
Security and fire alarm system "on break"
The following diagram is a security and fire alarm system. The circuit is more complicated than the previous one, since it uses as many as four transistor stages and one microcircuit. In fact, the circuit is simple, since it consists of the simplest cascades and allows a significant variation in the values of the elements. In fact, this scheme can be called a complete fire-security complex, which can easily be used to work in a large room or office. In this scheme, I suggest using two cell phone shortcut buttons at once.
Imagine that you carry a phone with two SIM cards. Then, when the motion sensors are triggered, one shortcut key will be pressed on the “security” phone, and the call received on your first SIM card will be displayed on the display of your phone as “Security triggered.” When fire detectors are triggered, another shortcut key will be pressed, and the call received on your second SIM card will be displayed as “Fire alarm”.
The sensors used are a motion sensor and a fire detector, which are freely available in any specialized security system stores. The cost of one, the most expensive sensor, is around 300 rubles. A special feature of connecting sensors is that security systems use sensors with normally closed contacts, or as they say “break contacts”. In the initial state of standby mode, the sensor output is closed, and when triggered in the event of an alarm, the contacts open.
Let us consider the operation of the circuit using the example of its lower half - the “fire department”. Transistor VT3 with elements R7, R8 and C2 is a single-vibrator. When the contacts of the fire sensor are closed, the plus of the capacitor is on ground, and it is discharged through resistor R8. When the sensor is triggered - the contacts are opened, capacitor C2 begins to charge through the circuit: +12 volt power source, resistor R7, + capacitor C2, base-emitter junction of transistor VT3, housing, - 12 volt power source. During charging, transistor VT3 opens. The VT4 transistor stage is inverting and also opens at input 13 of the DD1 switch microcircuit and closes the microcircuit key, which in turn closes the contacts of the quick call button “2” of the mobile phone. When capacitor C2 is charged, the transistors will close and the switch will turn off. Different brands of cell phones require different times to press the shortcut button. In our case, the switching time of the button is determined by the value of the elements R7, C2, and is approximately equal to 4 seconds. If this time is not enough for your phone, or, on the contrary, it is a lot, then you can change it by choosing other values of the indicated elements using the formula in which the charging time (in seconds) is equal to the multiplication of resistance (Ohm) by capacitance (farad):
When the contacts of the fire sensor are closed to their original state, capacitor C2 is discharged through resistor R8. The operation of the “security part” of the alarm system occurs in exactly the same way as the fire department.
The alarm circuit and sensors are powered from a low-power stabilized power supply unit with a voltage of 12 volts. You can purchase a similar power supply, and even with a backup battery, at the same specialized security systems store. To power the DD1 microcircuit, a +9 volt stabilizer chain is used, consisting of resistor R13, zener diode VD1 and capacitor C3.
About the elements of the circuit: Any type of security and fire alarm sensors can be used, including door reed switches (for opening when doors and windows are opened), ordinary thin copper wire for breaking, smoke detectors, thermal switches. When using several sensors, their contact groups should be connected not in parallel, but in series. To eliminate false alarms from mains voltage interference, it is necessary to connect the sensors through shielded wires. It is better if these are two twisted pairs in a copper braid (sensor power supply - one pair, contact group - the second pair). It is possible to do without them, but in some cases “false ones” cannot be ruled out, and why redo the wiring several times? You can use any silicon transistors. The K561KTZ switch chip can be replaced with K564KTZ, K1561KTZ, K176KT1. They are completely interchangeable in this scheme.
If you do not need security and fire alarms in “one bottle,” then you can assemble only the lower half of the circuit, connecting to it only those sensors that you need. And let me remind you that in order to ensure constant operation of the security device, regardless of the battery charge of the mobile phone, it is a good idea to provide constant power to the phone through a standard power adapter via a 220 volt network.
Car security alarm
The following alarm scheme is intended for car owners. Currently, car alarms have become widespread, the key fob of which has feedback. When the alarm goes off, it receives a signal and it “squeals” like crazy. This kind of alarm has many advantages, and only one significant drawback - with a range of more than 100 meters and the presence of walls that screen the radio signal, the connection between the key fob and the car alarm is lost. But the proposed scheme is free of this drawback; you will receive a call, even if you are on another continent of the planet.
The presented circuit works exactly the same as the previously described security and fire alarms. When the object's state changes, the cellular subscriber's number is dialed by closing one of the shortcut buttons. Naturally, you must first enter the phone menu and enter your cell phone number into the quick call memory, which you will need to call when the state of the controlled object changes.
The signal source for this warning system can be +12 volts, which goes to the alarm “bell” (loud speaker) when it is triggered. To ensure that the circuit does not respond to short pulses of opening and closing doors, there is an integrating circuit R1 C1 at the input of the circuit, and the emitter of transistor VT1 is connected to a voltage divider R3 R4. The transistor opens only after capacitor C1 is charged to a voltage of at least 6 volts. With the specified element ratings, this will happen only a second after the appearance of a continuous alarm signal. After transistor VT1 opens, inverting transistor VT2 opens. The charging of capacitor C2 with a voltage of 9 volts begins along the circuit: “+” of capacitor C3, emitter-collector VT2, capacitor C2, resistor R7, “-” of capacitor C3. While C2 is charging, the key element of the DD1 microcircuit closes the contacts going to the shortcut button. The switching time is determined by elements C2 and R7. To recharge a mobile phone battery from a car battery, there is a R9 VD2 chain. The element values are selected to recharge the phone battery with a voltage of 5 volts and a current of 15 mA. This current is sufficient to maintain the phone's battery charge, since the phone will always be in standby mode, and only if an alarm is triggered will it switch to call mode, which has a higher current consumption.
About the circuit elements: Any silicon transistors can be used. The K561KTZ switch chip can be replaced with K564KTZ, K1561KTZ, K176KT1. They are completely interchangeable in this scheme. To eliminate interference from the car's power electrical circuits, it is necessary to place the calling circuit and the telephone in close proximity.
Anti-theft system controlled via phone
The next option for using a mobile phone is a combination of two previously described options for non-standard use of a phone. This is one of the best options for an anti-theft device with feedback - using a mobile phone as a detector about changes in the state of the controlled vehicle and controlling its condition.
Imagine the situation: You flew away on a summer vacation to Magadan, left your car in your garage or just in a paid parking lot in your northern Sochi. You are sunbathing under the southern sun in a hot taiga clearing, and then a call comes to your Motorola from your car control device, informing you that there, in distant and cold Sochi, the car’s engine is started. For you, this is of course a cause for concern, but without losing your composure, you give a call to remotely turn off the car’s ignition. After that, call your neighbor and negotiate for half a liter so that he can take his karamultuk and check the condition of the car. And even if your neighbor did not complete the task, having encountered serious armed resistance from the thieves, you have time to call special forces until the thieves find and neutralize your “miracle console”. And in order to prevent this from happening, the attachment must be connected not to the gap of the entire ignition system, but only to one device, when turned off the engine does not work, for example, the fuel pump located in the gas tank. Thieves will not have time to get to the pump to determine that there is no power to it, because this sometimes requires disassembling the entire machine. The best option is if an engine malfunction is displayed on the driver’s display. According to statistics, a protected car is stolen in this way only if its value is high enough by high-level car thief specialists, and even then, after lengthy preparation, this turns not into a simple theft, but into theft using other means of transportation.
So, the integrated circuit of the anti-theft device looks like this:
The terminals marked in blue are those that are connected to the car, and those in green are those that are connected to the mobile phone. Both parts of the circuit were described earlier in this article and the article ““. The peculiarities consist in connecting an actuator to turn off not the ignition system, but the fuel pump located in the gas tank of the car. In addition, the device will notify you not when the alarm is triggered, as discussed earlier, but after turning on the car’s ignition system (when starting the engine). To save energy, both the main car battery and the additional battery, the principle of controlling the shutdown of one of the engine systems has been changed.
Unlike the previously described circuits, this anti-theft device circuit works as follows: When you call, the signal from the vibration output of your mobile phone opens the thyristor VS1. Now, if you turn on the car’s ignition, the control transistor VT4 and the buffer transistor VT5 will open, relay P1 will disconnect its contacts and the operation of the fuel pump will stop. If you turn off the ignition and then turn it on again, everything will happen again. By increasing the nominal value of capacitor C1, you can ensure that the car engine will start and stall after a few seconds, which will simulate its malfunction. As described earlier in this article, when you turn on the ignition, your mobile phone will receive a call, which you will enter into your contacts in advance as “The ignition is on,” or “The car is being stolen.”
About circuit elements: Use any supplied radio elements. A 30 percent discrepancy in the values of almost all elements is allowed. You can use any silicon transistors. The K561KTZ switch chip can be replaced with K564KTZ, K1561KTZ, K176KT1.
A prerequisite before non-standard use of a mobile phone: when registering a SIM card, disable all additional cellular services, context, receiving and sending SMS messages, which arrive in huge numbers on our phones without our desire. In addition, it is necessary to turn off the dynamic heads that produce call sounds and the subscriber's voice.
Considering that in your modifications you are going to use an old phone, then if you use it non-standardly, you need to take care of its operation for a long time. After all, on old phones, as a rule, due to the large number of charge-discharge cycles, the battery is very weak, and there is usually no point in buying a new battery. When modifying the phone, it is necessary to provide for its external power supply. This can be done through a standard phone connector, or without a connector, by making small holes in the phone body and applying power directly to the terminals going to the battery. The main thing is not to overdo it with the charging current. Otherwise, the battery may explode.
And one more important point: if you are going to use the device in an area with a cold climate, then you need to provide heating for the phone during the winter season. The device itself is not afraid of frost, but the phone may simply turn off due to the cold, and then there will be no point in your idea. I suggest using a semiconductor heater controlled by a temperature control circuit on the comparator. At its core, this is a thermostat chamber.
