In the previous post we have seen how we can use A9G GPS/GSM/GPRS pudding board using a serial debugging tool and list of AT commands that we can use it. In this post we will see how we can use Arduino program to send AT commands and explore different features of the A9G board.
Table of Contents
What we need ?
- A9G pudding board
- Arduino UNO or pro mini. I will use UNO.
- TTL to UART convertor module in case you are using Arduino pro mini. This is required to upload your Arduino code.
- 5v USB power source.
- Connectors
- An unlocked SIM
What we want to Achieve here?
In the first example we will try to get GPS info and send this to thingsspeak server. Also, we will add a feature to get GPS data on demand by sending an SMS.
Source Code
Download the code from github and update with you Api key from thingsspeak.com. Also update your mobile number on which you want to receive gps data on demand.
// PROGRAM TO SEND GPS LOCATION ON DEMAND AND SEND GPS DATA TO THINGSSPEAK SERVER //
///////////////////////////////////////////////////////////////////////////////////
#include <SoftwareSerial.h> // Library for using serial communication
#include <MicroNMEA.h> // Library for converting NEMA message
/***********************************/
SoftwareSerial AIA9G(3, 4); // Pins 3, 4 are used as used as software serial pins RX ,TX
SoftwareSerial GPSData(10, 11); // Pins 10, 11 are used as used as software serial pins RX ,TX
const String api_key="XXXXXXXXXXXXXXXXX"; //API Key from thingsspeak.com
char buffer[85];
const unsigned long eventInterval = 20000;
unsigned long previousTime = 0;
MicroNMEA nmea(buffer, sizeof(buffer));
unsigned long lastLog = 0;
//int state = 0;
float latitude_mdeg ;
float longitude_mdeg ;
//Setup and initialize
void setup()
{
// Set Baud rate for all 3 channels
Serial.begin(19200); // baudrate for serial monitor
AIA9G.begin(115200); // baudrate for GSM shield
GPSData.begin(9600); // baudrate for GPS data
Serial.println("Starting...");
// *************************************************************//
// Start Initializing A9G board.
// Initialize GPRS
AIA9G.println("\r");
AIA9G.println("AT+GPS=1\r");
delay(100);
AIA9G.println("AT+CREG=2\r");
delay(6000);
//AIA9G.print("AT+CREG?\r");
AIA9G.println("AT+CGATT=1\r");
delay(6000);
AIA9G.println("AT+CGDCONT=1,\"IP\",\"WWW\"\r");
delay(6000);
// AIA9G.println("AT+LOCATION=1\r");
AIA9G.println("AT+CGACT=1,1\r");
delay(6000);
//Initialize ends
//Initialize GPS
AIA9G.println("\r");
AIA9G.println("AT+GPS=1\r");
delay(1000);
//AIA9G.println("AT+GPSMD=1\r"); // Change to only GPS mode from GPS+BDS, set to 2 to revert to default.
AIA9G.println("AT+GPSRD=10\r");
delay(100);
// set SMS mode to text mode
AIA9G.println("AT+CMGF=1\r");
delay(1000);
//AIA9G.println("AT+LOCATION=2\r");
// set gsm module to tp show the output on serial out
AIA9G.println("AT+CNMI=2,2,0,0,0\r");
delay(1000);
AIA9G.print("AT+CMGS=\"+XXXXXXXXXX\"\r"); //Replace this with your mobile number
delay(1000);
//The text of the message to be sent.
AIA9G.print("Tracker active...");
AIA9G.write(0x1A);
delay(1000);
}
void loop()
{
unsigned long currentTime = millis();
GPSData.listen();
delay(1000);
while(GPSData.available()>0)
{
char inByte = GPSData.read(); // Get GPS data
Serial.print(inByte);
nmea.process(inByte);
}
Serial.println("");
latitude_mdeg = nmea.getLatitude();
longitude_mdeg = nmea.getLongitude();
Serial.print("Latitude (deg): ");
latitude_mdeg=latitude_mdeg / 1000000.;
Serial.println(latitude_mdeg, 6);
Serial.print("Longitude (deg): ");
longitude_mdeg=longitude_mdeg / 1000000.;
Serial.println(longitude_mdeg, 6);
Serial.println(nmea.isValid());
// sendGPSData();
//send data after someinterval
if (currentTime - previousTime >= eventInterval) {
/* Send data */
sendGPSData();
/* Update the timing for the next time around */
previousTime = currentTime;
}
AIA9G.listen();
//AIA9G.println("AT+CNMI=2,2,0,0,0"); // AT Command to recieve a live SMS
// delay(100);
if (AIA9G.available() > 0) {
String c = AIA9G.readString();
c.trim();
if (c.indexOf("GET-GPS") >= 0) { //Send GPS data on request by SMS //
AIA9G.print("\r");
delay(1000);
AIA9G.print("AT+CMGF=1\r");
delay(1000);
AIA9G.print("AT+CMGS=\"+XXXXXXXXXX\"\r"); // Replace this with your mobile number.
delay(1000);
//The text of the message to be sent.
AIA9G.print("www.google.com/maps/?q=");
AIA9G.println(latitude_mdeg, 6);
AIA9G.print(",");
AIA9G.println(latitude_mdeg, 6);
delay(1000);
AIA9G.write(0x1A);
delay(1000);
// state = 1;
}
}
}
//Send GPSData to server.
void sendGPSData(){
Serial.print("http://api.thingspeak.com/update?api_key="); // Display on Serial monitor
Serial.print(api_key);
Serial.print("&field1=");
Serial.print(latitude_mdeg,6);
Serial.print("&field2=");
Serial.print(longitude_mdeg,6);
Serial.println();
if(latitude_mdeg != 0 && longitude_mdeg !=0){ //update only if valid values.
//String url="AT+CIPSTART=\"TCP\",\"http://api.thingspeak.com/update?api_key=" + api_key + "&field1=" + (String)latitude_mdeg + "&field2=" + (String)longitude_mdeg + "\",80\r";
AIA9G.print("AT+HTTPGET=\"https://api.thingspeak.com/update?api_key=");
AIA9G.print(api_key);
AIA9G.print("&field1=");
AIA9G.print(latitude_mdeg,6);
AIA9G.print("&field2=");
AIA9G.println(longitude_mdeg,6);
// AIA9G.write(0x1A);
delay(100);
// Serial.println(url);
}
}
///// Below codes not used.
/*
String sendData(String command, const int timeout, boolean debug)
{
String response = "";
AIA9G.println(command);
long int time = millis();
while( (time+timeout) > millis())
{
while(AIA9G.available())
{
char c = AIA9G.read();
response+=c;
}
}
if(debug)
{
Serial.print(response);
}
return response;
}
*/Pin Connections
A9G Pudding board Arduino
TX1[AT Command] —————- Pin 4
RX1 [AT Command]—————- Pin 3
TX2 [GPS] ————————- Pin 11
RX2 [GPS] ————————- Pin 10
VUSB/VBAT —————————— 5v / 3.7 v
GND ——————————–GND
Note: if using 3.7 v battery then connect to VBAT
Schematic Diagram
Output in Arduino
Note: Make sure you have your SIM unlocked and keep the GPS module in open to get GPS data quickly.