Homemade GPS tracker on Arduino. The best GPS trackers for cars (beacons)

Personal GPS transmitters

Today, progress is proceeding at such a pace that devices that were previously bulky, expensive and highly specialized are quickly losing size, weight and price, but gaining many new functions.

This is how devices based on GPS technology reached pocket gadgets and firmly settled there, giving people new opportunities. It is especially worth highlighting individual GPS transmitters.

Essentially, these are the same GPS trackers, only designed for use not on a vehicle, but by a person in everyday life.

Depending on the model, several various devices. In the simplest version, it’s just a small box without a display, which allows you to control the movements of children, animals or some other objects, on which it is fixed.

Inside it there is a GPS module that determines coordinates on the ground, a GSM/GPRS module that transmits information and receives control commands, as well as a power source that provides autonomous operation During a long time.

Functionality of GPS transmitters

As the functionality increases, the following capabilities of the device appear:

Options for GPS transmitters

Depending on the configuration, transmitter housings may differ significantly. Various models are available in the form cell phones, classic navigators, or even wristwatches.

Colorful design of special versions and useful additions allow children to treat these devices not as “parental spies”, but as fashionable and practical gadgets.

As an advantage, it is worth mentioning the fact that many versions of the device can do without subscription fee for the services of specialized operators, and all the necessary information is sent to the client directly via the Internet or SMS messages, which allows significant savings on the maintenance of such equipment.

Articles about GPS trackers

In this article I will show how to use a gsm module with arduino using the sim800L as an example. The same instructions are quite suitable for using any other gsm modules, for example, sim900, etc., because all modules work in approximately the same way - this is the exchange of AT commands through the port.

I will show the use of the module with arduino using the example of an SMS relay, which can be used to control the device remotely via SMS commands. This can be used in conjunction with car alarms, etc.

The module is connected to Arduino via the UART interface of the software serial port, operating on 2 and 3 digital outputs Arduino nano.

Working with Arduino with GSM modules

To power the module, a voltage in the range from 3.6V to 4.2V is required, this means that you will have to use an additional voltage stabilizer, since the Arduino has a 3.3 volt stabilizer installed, which is not suitable for powering the module, the second reason to install an additional stabilizer is that the GSM module is serious load, since it has a weak transmitter that provides stable communication with the cellular station. Power for the Arduino nano is supplied to the VIN pin - this is a stabilizer built into the Arduino that ensures the module operates over a wide voltage range (6-10V). The relay module is connected according to the given program text to pin 10 of the Arduino nano and can easily be changed to any other that works as a digital output.

It works like this: install a SIM card in the GSM module, turn on the power and send an SMS with the text “1” to the number SIM cards in order to turn on our relay, to turn it off we send an SMS with the text “0”.

#include
SoftwareSerial gprsSerial(2, 3); // set pins 2 and 3 for software port
int LedPin = 10; // for relay

void setup()
{
gprsSerial.begin(4800);
pinMode(LedPin, OUTPUT);

// setting up message reception

gprsSerial.print("AT+CMGF=1\r");
gprsSerial.print("AT+IFC=1, 1\r");
delay(500);
gprsSerial.print("AT+CPBS=\"SM\"\r");
delay(500); // delay for command processing
gprsSerial.print("AT+CNMI=1,2,2,1,0\r");
delay(700);
}

String currStr = "";
// if this line is a message, then the variable will take the value True
boolean isStringMessage = false;

void loop()
{
if (!gprsSerial.available())
return;

char currSymb = gprsSerial.read();
if ('\r' == currSymb) (
if (isStringMessage) (
// if the current line is a message, then...
if (!currStr.compareTo("1")) (
digitalWrite(LedPin, HIGH);
) else if (!currStr.compareTo("0")) (
digitalWrite(LedPin, LOW);
}
isStringMessage = false;
) else (
if (currStr.startsWith("+CMT")) (
// if the current line begins with “+CMT”, then the next message
isStringMessage = true;
}
}
currStr = "";
) else if (‘\n’ != currSymb) (
currStr += String(currSymb);
}
}

Video version of the article:

Tags: #Arduino, #SIM800L

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Products used in this article:

← GPS logger on arduino | Relay control via COM port →

GSM scanner on RTL-SDR

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Main characteristics of the scanner

The GSM scanner scans downstream GSM channels and displays information about the signal level and whether the channel belongs to one of the three main cellular operators MTS, Beeline and Megafon. Based on the results of its work, the scanner allows you to save a list of identifiers base stations MCC, MNC, LAC and CI for all scanned channels.
A GSM scanner can be used to evaluate the GSM signal level and compare signal quality different operators, radio coverage assessments, when deciding on installing cellular signal amplifiers and adjusting their parameters, for educational purposes, etc.
The scanner runs under Windows and uses a simple and cheap receiver - RTL-SDR. You can read about RTL-SDR at:
RTL-SDR (RTL2832U) and software defined radio news and projects,
RTL-SDR – OsmoSDR,
RTL-SDR in Russian.
The RTL-SDR parameters determine the main characteristics of the scanner. Of course, a GSM scanner is not a replacement for normal measuring equipment.
The scanner is distributed free of charge, without any restrictions on use.
Current version supports the GSM 900 band and does not support GSM 1800. This is determined by the fact that the operating frequency of the RTL-SDR with the R820T tuner is limited to 1760 MHz. There is hope that the use of the experimental RTL-SDR driver will allow operation in at least part of the 1800 MHz range.

Starting the scanner

The latest version of the scanner can be downloaded from this link. Simply unzip the file to a convenient location and run gsmscan.exe.
Previous versions of the scanner, a link to the repository with sources and other information related to the development are located on the development page.
For the scanner to operate, the installation of RTL-SDR drivers is required; if they have not already been installed, this can be conveniently done using the Zadig program to describe the installation procedure.

Using the Scanner

Below is a view of the scanner program window:

The horizontal axis displays the GSM channel number in the form ARFCN or in MHz, according to vertical axis signal level in dBm. The height of the line shows the signal strength.

GSM module NEOWAY M590 communication with Arduino

If the BS identifiers have been decoded successfully and they correspond to the identifiers of the three major telecom operators, the lines are painted in the corresponding colors.
The drop-down lists at the top of the screen allow you to select the SDR receiver, if several are connected, the operating range GSM 900 or GSM 1800 and the units of measurement along the horizontal axis ARFCN or MHz.
The buttons allow you to save a report on the scanner’s operation in the form of a list of decoded base stations, clear the results of BS decoding and obtain information about the program.

Principles and features of work.

During operation, the program scans the operating frequency range with a step of 2.0 MHz (10 GSM channels) and digitizes the signal with a sampling frequency of 2.4 MHz. The scanning process consists of a fast pass through the entire range to measure signal strength and a slow pass to decode the BS identifiers.

One decoding step is performed after traversing the entire range to measure power. Thus, in the GSM 900 range, the signal level is updated approximately once every 2 s, and a complete decoding pass takes about 1 minute.
Due to the poor quality of the signal received from RTL-SDR, the probability of correctly decoding system information (SI) of the BS broadcast control channel (BCCH) is not high. Signal level fluctuations as a result of multipath propagation also reduce the likelihood of decoding system information. For these reasons, to obtain BS identifiers, it is necessary for the scanner to accumulate information over a period of about 10 minutes. But even in this case, not all channels provide this place sufficient signal level and quality for decoding even by the most ideal receiver. In addition, not all GSM channels are used to work according to the GSM standard, as can be seen in the figure above, channels 975 - 1000 are occupied by Megafon to work according to the UMTS standard.
During operation, the scanner adds system information about new decoded channels to the general array of information on channels. But information about previously decoded channels is not erased when system information is not decoded at this step, and remains in the array. To clear this information, use the button to clear the BS decoding results.
When you click on the save report button, the accumulated results are saved in text file with a name made up of the name of the program, the date and time the data was saved. Below is an example of part of the report file:
The scanner is designed to work under Windows 7, 8.1 and 10. The work was tested with three copies of the RTL-SDR with the R820T tuner; other types of tuners were not tested.
A special version of the program has been compiled to work under Windows XP; it runs several times slower than the standard version.

Development.

The scanner program is supplied as is, without any warranties or liability. If you have reasonable ideas on how to expand the functionality or improve the performance of the scanner, we are ready to discuss the possibility of their implementation.
You can take part in the development of the scanner; to do this, visit the development page.
Further development of the GSM scanner is planned, possibly with your participation.

Do you need an accurate time source from GPS? This article will show you how to use a GPS module to get time, date and coordinates, and how to display them on an LCD using Arduino.

What is necessary?

• computer with Arduino IDE installed;
• Arduino (we use Arduino Mega);
• GPS module (we use EM-411, others are possible that support NMEA protocol, for example, VK2828U7G5LF or GY-NEO6MV2);
• breadboard, jumpers and 5 kOhm potentiometer;
• TinyGPS library (link below).

Introduction

The development of the global positioning system, or GPS, began in the early 1970s. Each country (Russia, USA, China, etc.) has its own system, but most satellite navigation facilities in the world use the US system.

Each satellite in the system has an atomic clock that is continuously monitored and adjusted by NORAD (North American Aerospace Defense Command) every day.

Essentially, the receiver uses its clock to measure the TOA (time of arrival) of four satellite signals. Based on TOA and TOT (time of transmission), the receiver calculates four values ​​of time of flight (TOF), which differ from each other depending on the distance from the satellite to the receiver. Then, from the four TOF values, the receiver calculates its position in 3D space and the deviation of its clock.

The most inexpensive GPS receivers have an accuracy of about 20 meters for most places on Earth. Now let's see how to make your own GPS clock using Arduino.

Hardware

My GPS module has 6 pins: GND, Vin, Tx, Rx and GND again. The sixth pin is not connected anywhere. The GND pin is connected to the case on the Arduino, Vin is connected to the +5V bus on the Arduino, Tx is connected to pin 10 on the Arduino, and the Rx pin is not connected anywhere, since we will not send any messages to the GPS module. My module transmits satellite data using the RS-232 interface at 4800 bps, which is received by the Arduino on pin 10.

Below is a photo of the GPS module:

GPS module EM-411

The module sends what are known as NMEA messages. Here you can see an example of one NMEA message and its explanation (excerpt from technical description):

$GPGGA,161229.487,3723.2475,N,12158.3416,W,1.07,1.0,9.0,M,0000*18

All this data is received by the Arduino via pin 10. The TinyGPS library reads GPGGA and GPRMC messages (for detailed information about GPRMC see technical description).

Arduino is not shown in the diagram. Connect peripherals according to signed connections.

Software

When power is applied, the GPS module takes some time to obtain the correct location from the satellites. When a location is received, the module sends NMEA messages to the Arduino. The TinyGPS library contains a function to get the time and date from a GPRMC message. It's called crack_datetime() and takes seven pointers to variables as parameters: year year , month month , day of month day , hour hour , minutes minute , seconds second , and hundredths of a second hundredths . The function call looks like this:

GPS.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths);

Calling this function returns you the correct values ​​in the variables as long as everything is in order with the hardware.

To get your location, you can call the f_get_position() function. This function takes as parameters two pointers to variables: latitude latitude and longitude longitude . Calling this function looks like this:

Gps.f_get_position(&latitude, &longitude);

Source text of the program:

#include #include #include #define RXPIN 10 #define TXPIN 9 #define GPSBAUD 4800 #define RS 2 #define EN 3 #define D4 4 #define D5 5 #define D6 6 #define D7 7 TinyGPS gps; SoftwareSerial uart_gps(RXPIN, TXPIN); LiquidCrystal lcd(RS, EN, D4, D5, D6, D7); // Variables int seconds; int timeoffset = 1; // The user must change the unit to the appropriate time zone. In the example we use a shift of +1 hour. // Declaration of functions. void getgps(TinyGPS &gps); // Setup function - runs only when turned on void setup() ( Serial.begin(115200); // Start the serial interface for debugging uart_gps.begin(GPSBAUD); // Start the UART receiver for GPS lcd.begin(16,2) ; // LCD announcement lcd.print("GPS clock"); // Welcome message delay(1000); // Wait one second lcd.clear(); // Clear LCD ) // Loop main program- void loop() is always running ( while(uart_gps.available()) ( int c = uart_gps.read(); if(gps.encode(c)) ( getgps(gps); ) ) ) /* * This function receives data from the GPS module * and displays them on the LCD */ void getgps(TinyGPS &gps) ( int year; float latitude, longitude; byte month, day, hour, minute, second, hundredths; gps.f_get_position(&latitude, &longitude); gps .crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths); hour = hour + timeoffset; lcd.clear();//lcd.setCursor(0, 0); lcd.print("Time: ") ; if (hour<= 9) { lcd.print("0"); lcd.print(hour, DEC); } else { lcd.print(hour, DEC); } lcd.print(":"); if (minute <=9) { lcd.print("0"); lcd.print(minute, DEC); } else { lcd.print(minute, DEC); } lcd.print(":"); if (second <= 9) { lcd.print("0"); lcd.print(second, DEC); } else { lcd.print(second, DEC); } lcd.setCursor(0,1); lcd.print("Date: "); if (day <= 9) { lcd.print("0"); lcd.print(day, DEC); } else { lcd.print(day, DEC); } lcd.print("-"); if (month <= 9) { lcd.print(month, DEC); } else { lcd.print(month, DEC); } lcd.print("-"); lcd.print(year, DEC); delay(2000); lcd.clear(); lcd.print("Lat: "); lcd.print(latitude, DEC); lcd.setCursor(0,1); lcd.print("Lon: "); lcd.print(longitude, DEC); delay(2000); // Debugging purpose only. Serial.print(latitude, DEC); Serial.print(" - "); Serial.println(longitude, DEC); }

Today we will make a GPS Tracker based on Arduino MKR FOX 1200 that sends accurate GPS data via Sigfox network.

This is becoming even more relevant for many countries due to increased control over any imported technical devices, especially those related to GPS.

Step 1. What we will need

The set of parts for this lesson is not large:

• Arduino MKR Fox 1200 × 1
• GPS module (optional, but we used a replica of ublox NEO6m (ATGM332D) × 1
• General purpose NPN transistor (we used BC548) × 1
• Resistor 1 kOhm × 1

Step 2. Project information

The tracker uses the ATGM332 GPS module to obtain GPS position with greater accuracy than the location services provided by Sigfox. The item data is then sent as a "string" through the Sigfox network and finally delivered via email.

Arduino MKR FOX 1200

The board is similar to the Arduino Zero, which is based on the SAM D21 and includes an ATA8520 Sigfox module. This is a low-power board that comes with the board with a free one-year subscription to the Sigfox network (up to 140 messages per day), as well as free access to the location service Spot"it.

GPS module ATGM332

This low-cost, low-power GPS module fits the Arduino MKR FOX 1200 very well as it only works with 2.7V (nominal 3.3V).

Initially I was supposed to buy the NEO6m2 module, which has a standby mode, but I had to use NEO6. In fact it was an ATGM332 module. As a result, it had no standby mode, so it was necessary to use a transistor to turn the GPS module on when needed and turn it off to save battery. Our goal is to have location information quite infrequently, i.e. 4 messages per hour, since Sigfox only allows 140 messages per day.

We use the TinyGPS library (https://github.com/mikalhart/TinyGPS) to decode GPS frames.

Transistor switch

It was necessary to turn GPS on and off when necessary. Relay modules are too bulky and powerful if you only need to switch a 3V load and a few milliamps. Also, most relay modules require 5V. So a transistor would be a better solution. Additionally, the MKR FOX 1200 only provides 7 mA on the I/O pin.

A BC548 NPN transistor will do. When the zero signal is applied to the base of the transistor, it turns off, acting like an open switch, and no collector current flows. When a positive signal is applied to the base of the transistor, it becomes "on", acting as a closed switch, and maximum circuit current flows through the device.

Step 3. Connection diagram

The only power source is two 1.5V AA batteries that power the Arduino MKR FOX 1200. The GPS module receives power from the Arduino board.

The Arduino MKR FOX 1200 communicates with the GPS module using the second serial port via pins 13 and 14, called Serial1 in the code. The TX data output of the GPS module is connected to the serial data input (pin 13) of the Arduino board.

Additionally, the Arduino board uses PIN2 to turn the GPS module on and off, as explained above.

Step 4. Project code

You can download or copy the code of our project below: