Thus, it is quite easy to create a GSM alarm based on the Arduino board with your own hands. Such an alarm at its cost will, of course, be cheaper than proprietary counterparts on the market today, and it will function in an almost identical way.

This project concerns the development and improvement of a system to prevent / control any attempts to enter by thieves. The developed security device uses an embedded system (includes a hardware microcontroller using open source software and a gsm modem) based on GSM (Global System for Mobile Communications) technology.

The security device can be installed in the house. The interface sensor for the burglar alarm is also connected to the controller-based burglar alarm system.
When an attempt is made to penetrate, the system sends a warning message (for example, sms) to the owner on the mobile phone or to any pre-configured mobile phone for further processing.

The security system consists of an Arduino Uno microcontroller and a standard SIM900A modem based on GSM / GPRS. The whole system can be powered by any 12V 2A power supply / battery.

Below is a diagram of an Arduino-based security system.

The operation of the system is very simple and self-explanatory. When power is applied to the system, it enters standby mode. When the pins of connector J2 are shorted, a preprogrammed warning message is sent to the required mobile number. You can connect any intrusion detector (such as a light guard or motion detector) to the J2 input connector. Note that the active-low (L) signal on pin 1 of J2 will activate the burglar alarm.

Moreover, an optional “call - alarm” device has been added to the system. It activates the phone call when the user presses the S2 button (or when another electronic unit triggers an alarm). After pressing the “call” button (S2), the call can be canceled by pressing another button S3 - the “end” button. This option can be used to generate a “missed call” alarm in the event of intrusion.

The circuit is very flexible, so it can use any SIM900A modem (and of course the Arduino Uno board). Read the documentation for your modem carefully before starting assembly. This will make the process of making the system easier and more enjoyable.

List of radioelements

Good time of day 🙂 Today we'll talk about alarm. The service market is full of companies, organizations that are engaged in the installation and maintenance of security systems. These firms offer the buyer a wide variety of alarm systems. However, their cost is far from cheap. But what should a person who does not have so many personal funds do that can be spent on a burglar alarm? I think the conclusion suggests itself - do alarm by their hands... This article provides an example of how you can make your own coded security system using an Arduino uno board and several magnetic sensors.

The system can be deactivated by entering the password from the keypad and pressing the ‘ * ‘. If you want to change the current password, you can do it by pressing the ‘ B', And if you want to skip or interrupt the operation, you can do it by pressing the key ‘#’. The system has a buzzer for playing various sounds when performing a particular operation.

The system is activated by pressing the 'A' button. The system gives 10 seconds to leave the premises. After 10 seconds the alarm will be activated. The number of magnetic sensors will depend on your own desire. The project involves 3 sensors (for two windows and a door). When the window is opened, the system is activated and the alarm goes off from the buzzer. The system can be deactivated by entering a password. When the door is opened, the alarm gives the visitor 20 seconds to enter the password. The system uses an ultrasonic sensor that can detect movement.

Video of device operation

Craft made for informational / educational purposes. If you want to use it at home, you will need to refine it. Enclose the control unit in a metal case and secure the power line from possible damage.

Let's get started!

Step 1: what we need

• Arduino uno board;
• high-contrast LCD display 16 × 2;
• 4 × 4 keyboard;
• 10 ~ 20kΩ potentiometer;
• 3 magnetic sensors (they are also reed switches);
• 3 2-pin screw terminals;
• HC-SR04 ultrasonic sensor;

If you want to build a system without using an Arduino, you will also need the following:

• DIP connector for atmega328 + atmega328 microcontroller;
• 16MHz crystal resonator;
• 2 pcs. 22pF ceramic, 2 pcs. 0.22uF electrolytic capacitor;
• 1 PC. 10k ohm resistor;
• power socket (DC power jack);
• bread board;
• 5V power supply;

And one box to pack it all!

Instruments:

• Something that can cut a plastic box;
• Hot glue gun;
• Drill / screwdriver.

Step 2: Alarm circuit

The connection diagram is quite simple.

Small clarification:

High contrast LCD:

• Pin1 - Vdd to GND;
• Pin2 - Vss to 5V;
• Pin3 - Vo (to the center pin of the potentiometer);
• Pin4 - RS to pin 8 of Arduino;
• Pin5 - RW to GND;
• Pin6 - EN to pin 7 of Arduino;
• Pin11 - D4 to pin 6 of Arduino;
• Pin12 - D5 to pin 5 of Arduino;
• Pin13 - D6 to pin 4 of Arduino;
• Pin14 - D7 to pin 3 of Arduino;
• Pin15 - Vee (to the right or left pin of the potentiometer).

4 × 4 keyboard:

Left to Right:

• Pin1 to A5 pin of Arduino;
• Pin2 to A4 pin of Arduino;
• Pin3 to A3 pin of Arduino;
• Pin4 to A2 pin of Arduino;
• Pin5 to pin 13 of Arduino;
• Pin6 to pin 12 of Arduino;
• Pin7 to pin 11 of Arduino;
• Pin8 to pin 10 of Arduino.

Step 3: Firmware

The step presents the code that is used by the built-in!

Download the codebender plugin. Click on the "Run" button in the Arduino and flash your board with this program. That's all. You've just programmed the Arduino! If you want to make changes to the code, click the "Edit" button.

Note: If you will not be using Codebender IDE to program your Arduino board, you will need to install additional libraries in the Arduino IDE.

Step 4: making your own control board

After you have successfully assembled and tested a new project based on Arduino uno, you can start making your own board.

A few tips for a more successful completion of the undertaken:

• A 10K resistor must be wired between the 1 (reset) and 7 (Vcc) pins of the Atmega328 microcontroller.
• A 16MHz crystal should be connected to pins 9 and 10, labeled XTAL1 and XTAL2
• Connect each lead of the resonator to 22pF capacitors. Lead free capacitor leads to pin 8 (GND) of the microcontroller.
• Remember to connect the second ATmega328 power line to the power supply, the 20-Vcc and 22-GND pins.
• You can find more information on the microcontroller pins in the second image.
• If you plan to use a power supply with a voltage higher than 6V, you must use a linear regulator LM7805 and two 0.22uF electrolytic capacitors, which should be mounted at the input and output of the regulator. It is important! Do not apply more than 6V to the board !!! Otherwise you will burn your Atmega microcontroller and LCD display.

Step 5: Place the circuit in the case

Spring, as you know, is accompanied by all sorts of exacerbations, and the main “exacerbation” has climbed out of its holes into the street in order to appropriate for itself what does not belong to it. This means that the topic of protecting your property is becoming more relevant than ever.
The site already has several reviews on homemade -. They are of course functional, but they all have a common feature - dependence on an outlet. If this is not a problem with real estate, where electricity has already been supplied, then what about property where the outlet is far away or the surroundings are completely de-energized? I decided to go the other way - to assemble a long-lived, maximally simple and independent from the mains supply device, which will sleep all the time, and when the robbers penetrate, start and call the owner on the phone, signaling with a simple alarm call.

Review items

Mined from the ruins of civilization:
1. Racks for the board, sawn out of the instrument cases - 6 pcs.
2. Battery lithium flat 1300mAh
3. Brackets used to fix the cable to the wall
4. Stationery eraser
5. Copper wire 1.5mm thick
6. Instrument case from the local radio market - 1.5$
7. A pair of LEDs of different colors (taken from a VHS player)
8. Antenna and a button with a cap (taken from a Wi-Fi router)
9. 4-pin terminal block (taken from the dimmer)
10. Power connector (taken from an old 18650 charger)
11. 6-pin connector (taken from a DVD drive)
12. Tin can (for coffee for example)

Arduino Pro Mini "RobotDyn" Atmega 168PA 3.3V 8MHz

The choice fell on this atmega quite by accident. on one forum where energy-efficient projects were discussed, in the comments came across advice to use exactly the 168th atmega.
However, I had to tinker to find such a board, since all the lots were often littered with 328 atmegs at a frequency of 16 MHz, operating from 5V. For my project, such characteristics were redundant and inconvenient from the very beginning, the search became more complicated.
As a result, I came across a 3.3-volt version of the Pro Mini on the Atmega 168PA on eBay, and not just a simple Chinese one, but under the RobotDyn brand from a Russian developer. Yes, I, too, at first, like you, had a grain of doubt. But in vain. When the project was already assembled, and AliExpress introduced a mandatory paid delivery for cheap goods (after which the parcels were lost much more often), then later I ordered the usual Pro Mini Atmega168 (without PA) 3.3V 8MHz. I experimented a little with power-saving modes with both boards, flashing a special sketch into each, immersing the microcontroller in the maximum power-saving mode, and this is what happened:
1) Arduino Pro Mini "RobotDyn": ~ 250μA
2) Arduino Pro Mini "NoName": when power was applied to the voltage regulator (RAW output) and the LED was removed, the current consumption was ~ 3.92mA




- as you understand, the difference in power consumption is almost 16 times, this is because the NoName "Pro Mini uses a bunch of Atmega168 +, of which the MK itself eats only 20μA current (I checked this separately), all the rest of the gluttony falls on the AMS1117 linear voltage converter - the datasheet only confirms this:


In the case of the RobotDyn board, the bundle is somewhat different - this is Atmega168PA + - here we have used another LDO stabilizer, whose characteristics in terms of energy saving turned out to be more pleasant:


I didn't solder it, so I can't say how much Atmega168PA consumes current in its pure form. In this case, I had enough ~ 250μA when powered by a Nokia lithium battery. However, if you solder AMS1117 from the NoName "of the motherboard, then the ATmega168 is an ordinary one, in its pure form, as I said above, it consumes 20μA.
Power LEDs can be knocked off with something sharp. It's not a problem. The stabilizer was soldered with a hairdryer. However, not everyone has a hairdryer and the skills to work with it, so both of the above options have a right to exist.

Neoway M590E module

The cheapest GSM-module that can be found on the market, as a rule, is second-hand, not always soldered by clever Chinese hands from equipment. Why not always dexterous? Yes, all because of soldering with a hairdryer - often people come with these modules with a short-circuited plus and minus, which is one of the reasons for their inoperability. Therefore, the first step is to ring the power contacts for a short circuit.

Note. A separate important point, in my opinion, I would like to note - these modules can come with a round coaxial connector for the antenna, which allows you to separately order a more serious antenna and connect it to the module without dancing with a tambourine. And they can come without this connector. This is when we talk about the cheapest sets. If you don't want to rely on a fluke, then there are a little more expensive sets, where this connector is present + an external antenna on a textolite board is included in the kit.

If you click on "Connect" and then start the module by applying BOOT through a 4.7K resistor to ground, then the terminal will first display the message "MODEM: STARTUP", then, after a while, the inscription "+ PBREADY", which means that the telephone number has been read. book, even though it may be empty:

Under this spoiler, AT teams with examples

We print the AT command - in response, the module sends us our command, since the echo mode is enabled, and OK:

Let's check the status of the modem with the AT + CPAS command - in response, our command is again, + CPAS: 0 and OK.
0 - means that the module is ready for operation, but depending on the situation, there may be other numbers, for example, 3 - incoming call, 4 - in connection mode, 5 - sleep mode. I did not find information on 1 and 2.

Changing the data transfer rate on the UART is performed by the command AT + IPR = 9600 - this is if the speed is 9600. If any other, it is similar to AT + IPR = 19200 for example or AT + IPR = 115200.

Let's check the network signal. AT + CSQ, the answer comes + CSQ: 22.1 - the value to the decimal point has a range of 0 ... 31 (115 ... 52dBl) - this is the signal level, the more the better. But 99 means his absence. The value after the decimal point is the signal quality 0 ... 7 - here it is already the opposite, the lower the number, the better.

Disable echo mode by sending the ATE0 command so that duplicate commands do not get in the way. Inversely, this mode is turned on by the ATE1 command.

View firmware version AT + GETVERS

Aligning boards

Later I had to make another hole, in my case on the letter "I", where it says "Made In China", on the edge of the board.


It turned out that the added contact, which is essentially GND, became located next to the GND of the Pro Mini board, and thus it became possible to combine the ground of the GSM module and the Pro Mini with a drop of solder (the long pin in the middle and to the right of it is the Pro Mini pin) - I marked them with arrows. Of course it turned out a little crooked, but now it is holding on reliably:

There is some space left between the boards - I placed a lithium discharge charge control board with a pre-soldered microUSB connector and soldered wires in it.

The scarf fits there very tightly, while the glow of the LEDs from the side will be clearly visible through a small hole in the case.

PCB stands

Connectors. LEDs. Button.

The body of the 6-pin connector was slightly finished off with a file, because its edges protruded slightly above the body. The charging socket fits perfectly against the wall of the case.

On the other side of the board, I soldered a button to reboot the device and two LEDs for debugging the firmware - the red LED is connected to the GSM module, the second green LED to pin 10 of the Pro Mini - it's easier for me to debug the program using it.

Refinement of the battery

Fitting on a battery:

You can fix the terminal block with a rubber band or wrap it with blue electrical tape, which I did in the end.

Assembly.

When charging is connected:

Frame. External terminal block.

Drilling holes, although simple at first glance, is still no less time consuming, it is very easy to miss, so I did it first with a smaller drill, then a larger one.

For the tact button, I selected a cap with a slightly concave top so that it would be convenient to hit it with a match or a paper clip through a narrow hole in the case.

Board in a case with a USB-TTL converter loop connected:

About the antenna.
The antenna, as you may have noticed along the way, was constantly changing, as I experimented with different homemade antennas. Initially, there was a round coaxial connector on the module board, but the fifth time it was used for an external antenna, it just fell apart, so keep in mind that it is flimsy. As a result, I tore out the antenna on the PCB from the old router, and soldered it to the module board, tk. it catches the net a little better than the spring and wire.

Well, completely assembled with a connected charger looks like this:

Test. How it works:

The principle of operation is organized by an external interrupt, initially pin 2 is closed to VCC and thus a logical 1 is supported on the pin, and the controller sleeps. As soon as the contact is broken and 0 appears on pin 2, the microcontroller wakes up, lowers the 3rd pin (to which the BOOT modem is connected through a resistor) to the ground - the module starts up, the MC periodically polls the module for readiness, and as soon as it catches the network, it immediately sends a call to the owner's phone number specified in the code. After rejecting the call, the device shuts down without sending more endless calls than many Chinese alarms do.

Additional Information

#include #include // library of software UART SoftwareSerial gsm (7, 6); // RX (7), TX (6) void wakeUp () () // empty interrupt handler //////////////////////////// /////////////// void gsmOFF () (// PORTD | = (1<<3); // ВЫКЛЮЧЕНИЕ МОДУЛЯ _delay_ms(10); // gsm.println("AT+CPWROFF"); // ПЕЧАТАЕМ КОМАНДУ OFF PORTB &=~ (1<<2); // выключить LED 10 } // //========================================= void gsmON(){ // PORTD|=(1<<6); // 6-му порту (TX) назначить 1 PORTD &= ~(1<<3); // ЗАПУСК МОДУЛЯ _delay_ms(10); // while(!gsm.find("+PBREADY")); // ждём прочтения тел. книги PORTB |= (1<<2); // включить LED 10 _delay_ms(100); // while(1){ // gsm.println("AT+CREG?"); // проверяем в сети ли модуль if (gsm.find("0,1")) break; // если сеть есть, выходим из цикла _delay_ms(400); // проверка раз в 0,4 сек } // } // /////////////////////////////////////////// // void sleepNow(){ // функция засыпания ADCSRA = 0x00; // отключить подсистему АЦП (экономия 140 мкА) PORTD&=~(1<<6); // в вывод TX поставить 0 _delay_ms(100); // set_sleep_mode(SLEEP_MODE_PWR_DOWN); // режим сна PWR_DOWN sleep_enable(); // включение сна attachInterrupt(0, wakeUp, LOW); // включить прерывания sleep_mode(); // sleep_disable(); // detachInterrupt(0); // отключить прерывания } void setup(){ gsm.begin(9600); // скорость работы UART DDRD = B01001000; // 3-й и 6-й выводы на выход DDRB |= (1<<2); // вывод 10 на выход gsmON(); // запуск модуля для теста gsmOFF(); // выключаем модуль } void loop(){ if (!(PIND&(1<<2))){ // если на 0-ом прерывании появился 0 gsmON(); gsm.println("ATD+79xxxxxxxxx;"); // отзваниваемся, в ответ приходит OK и CONNECT _delay_ms(100); if (gsm.find("OK")) while(1){ // ожидание сброса вызова gsm.println("AT+CPAS"); // при каждой итерации опрашиваем модуль if (gsm.find("0")) break; // если 0, то выходим из цикла while _delay_ms(100); // проверка раз в 0,1 сек } for (char i=0; i<14; i++){ PORTB|=(1<<2); // LED 10 ON _delay_ms(200); PORTB&=~(1<<2); // LED 10 OFF _delay_ms(200); } gsmOFF(); // выключить модуль _delay_ms(10); while(1); // блокируем программу } else { sleepNow(); // укладываем контроллер спать } }

Circuit (without charge-discharge control board)

Conclusions and thoughts. Plans.