How to Send a Temperature Emergency SMS Using Tracking Kit (GPRS + GPS)
Difficulty Level: Intermediate -
1. Introduction
This tutorial allows the user to measure the temperature of an object. When the temperature is 0ºC or less, a text message is sent to a mobile phone in which the temperature and the position (laltitude and longitude) of the module is indicated.
Ingredients:
-
- 1 x Tracking Kit (GPRS + GPS):
- 1x Platform
- 1x GPRS+GPS Quadband Module (SIM908)
- 1x GPRS antenna
- 1x GPS antenna
- 1x Temperature sensor (MCP9700A)
- 1x Breadboard
- 1x External power supply
- 1x Programming cable
- Jumper Wires
Preparation Time: 30 minutes
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NOTE: Depending on the platform chosen to develop the project, the ingredients and the schematics shown in this tutorial can vary.
This project can be developed with Arduino or Intel Galileo. It is also compatible with Raspberry Pi using the Raspberry Pi to Arduino shields connection bridge.
For further information about the GPRS+GPS (SIM908) Shield, consult the main tutorial.
Step 1: Connection
Connect the GPRS and GPS antenna to the shield and then, connect the shield to the Arduino or to Raspberry Pi connection bridge. Connect temperature sensor in the breadboard as you can see in the next diagram.
Connect two wires, red and black, to the two long rows on the side of the breadboard to provide access to the VCC supply (5V in Arduino and 3.3V in Raspberry Pi) and ground. Place the sensor with the flat part looking up like the diagram. Connect the left leg of the sensor to GND and the right to VCC. Connect the central leg to the first pin at bottom left of the shield (Analog 0).
WARNING: In Raspberry Pi, GPIO voltage levels are 3.3 V and are not 5 V tolerant. There is no over-voltage protection on the board. Digital inputs use a 3V3 logic level and are not tolerant of 5V levels, such as you might find on a 5V powered Arduino.
Extreme caution when working with GPIO, you may damage your Raspberry Pi, your equipment and potentially yourself and others. Doing so is at your own risk!
Step 2: The Code
Arduino:
Code:
/*
* GPRS+GPS Quadband Module (SIM908)
*
* Copyright (C) Libelium Comunicaciones Distribuidas S.L.
* http://www.libelium.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* a
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*
* Version: 1.0
* Design: David Gascón
* Implementation: Victor Boria
*/
//Enter here you data
const char pin_number[] = "****"; // Write the pin number of the SIM card
const char phone_number[] = "*********"; // Write the number to send the SMS
int onModulePin = 2;
char aux_string[30];
int8_t answer;
int flag = 0;
float temperature = 0.0; // Stores the calculated temperature
int sample; // Counts through ADC samples
float ten_samples = 0.0; // Stores sum of 10 samples
char frame[200];
char latitude[15];
char longitude[15];
char altitude[6];
char date[16];
char time[7];
char satellites[3];
char speedOTG[10];
char course[10];
void setup() {
pinMode(onModulePin, OUTPUT);
Serial.begin(115200);
Serial.println("Starting...");
power_on(); // Powering the module
delay(5000);
//sets the PIN code
sprintf(aux_string, "AT+CPIN=%s", pin_number);
sendATcommand(aux_string, "OK", 2000);
delay(3000);
Serial.println("Connecting to the network...");
//Check network registration
while ( (sendATcommand("AT+CREG?", "+CREG: 0,1", 1000) ||
sendATcommand("AT+CREG?", "+CREG: 0,5", 1000)) == 0 );
sendATcommand("AT+CLIP=1", "OK", 1000);
while ( start_GPS() == 0);
Serial.println("Connected to the network!!");
delay(1000);
while (Serial.available() != 0)
{
Serial.read();
}
}
void loop() {
measure_temperature();
//Send SMS if temperature is 0 or below 0
//Only send one SMS because of the flag, to reset the flag, reset Arduino
if (temperature <= 0 && flag == 0) {
get_GPS();
delay(500);
sendSMS();
delay(100);
flag++;
}
}
/************************************************************************
**** Definition of functions ****
************************************************************************/
void measure_temperature()
{
// take 10 samples from the MCP9700
for (sample = 0; sample < 10; sample++) {
// convert A0 value to temperature
temperature = ((float)analogRead(A0) * 5.0 / 1024.0) - 0.5;
temperature = temperature / 0.01;
temperature = temperature - 5.3;
// sample every 0.1 seconds
delay(100);
// sum of all samples
ten_samples = ten_samples + temperature;
}
// get the average value of 10 temperatures
temperature = ten_samples / 10.0;
// send temperature out of serial port
Serial.print(temperature);
Serial.println(" deg. C");
ten_samples = 0.0;
}
void power_on() {
uint8_t answer = 0;
// checks if the module is started
answer = sendATcommand("AT", "OK", 2000);
if (answer == 0)
{
// power on pulse
digitalWrite(onModulePin, HIGH);
delay(3000);
digitalWrite(onModulePin, LOW);
// waits for an answer from the module
while (answer == 0) { // Send AT every two seconds and wait for the answer
answer = sendATcommand("AT", "OK", 2000);
}
}
}
int8_t sendATcommand(char* ATcommand, char* expected_answer, unsigned int timeout) {
uint8_t x = 0, answer = 0;
char response[100];
unsigned long previous;
memset(response, '\0', 100); // Initialice the string
delay(100);
while ( Serial.available() > 0) Serial.read(); // Clean the input buffer
if (ATcommand[0] != '\0')
{
Serial.println(ATcommand); // Send the AT command
}
x = 0;
previous = millis();
// this loop waits for the answer
do {
if (Serial.available() != 0) { // if there are data in the UART input buffer, reads it and checks for the asnwer
response[x] = Serial.read();
//Serial.print(response[x]);
x++;
if (strstr(response, expected_answer) != NULL) // check if the desired answer (OK) is in the response of the module
{
answer = 1;
}
}
} while ((answer == 0) && ((millis() - previous) < timeout)); // Waits for the asnwer with time out
return answer;
}
int8_t start_GPS() {
unsigned long previous;
previous = millis();
// starts the GPS
sendATcommand("AT+CGPSPWR=1", "OK", 2000);
sendATcommand("AT+CGPSRST=0", "OK", 2000);
// waits for fix GPS
while (( (sendATcommand("AT+CGPSSTATUS?", "2D Fix", 5000) ||
sendATcommand("AT+CGPSSTATUS?", "3D Fix", 5000)) == 0 ) &&
((millis() - previous) < 90000));
if ((millis() - previous) < 90000)
{
return 1;
}
else
{
return 0;
}
}
int8_t get_GPS() {
int8_t counter, answer;
long previous;
// First get the NMEA string
// Clean the input buffer
while ( Serial.available() > 0) Serial.read();
// request Basic string
sendATcommand("AT+CGPSINF=0", "AT+CGPSINF=0\r\n\r\n", 2000);
counter = 0;
answer = 0;
memset(frame, '\0', 100); // Initialize the string
previous = millis();
// this loop waits for the NMEA string
do {
if (Serial.available() != 0) {
frame[counter] = Serial.read();
counter++;
// check if the desired answer is in the response of the module
if (strstr(frame, "OK") != NULL)
{
answer = 1;
}
}
// Waits for the asnwer with time out
}
while ((answer == 0) && ((millis() - previous) < 2000));
frame[counter - 3] = '\0';
// Parses the string
strtok(frame, ",");
strcpy(longitude, strtok(NULL, ",")); // Gets longitude
strcpy(latitude, strtok(NULL, ",")); // Gets latitude
strcpy(altitude, strtok(NULL, ".")); // Gets altitude
strtok(NULL, ",");
strcpy(date, strtok(NULL, ".")); // Gets date
strtok(NULL, ",");
strtok(NULL, ",");
strcpy(satellites, strtok(NULL, ",")); // Gets satellites
strcpy(speedOTG, strtok(NULL, ",")); // Gets speed over ground. Unit is knots.
strcpy(course, strtok(NULL, "\r")); // Gets course
convert2Degrees(latitude);
convert2Degrees(longitude);
return answer;
}
void sendSMS() {
Serial.print("Setting SMS mode...");
sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text
Serial.println("Sending SMS");
sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number);
answer = sendATcommand(aux_string, ">", 2000); // send the SMS number
if (answer == 1)
{
Serial.print("Help me! My temperature is critical. Find me in:");
Serial.print("Latitude: ");
int i = 0;
while (latitude[i] != 0) {
Serial.print(latitude[i]);
i++;
}
Serial.print(" / Longitude: ");
i = 0;
while (longitude[i] != 0) {
Serial.print(longitude[i]);
i++;
}
Serial.write(0x1A);
answer = sendATcommand("", "OK", 20000);
if (answer == 1)
{
Serial.print("Sent ");
}
else
{
Serial.print("error ");
}
}
else
{
Serial.print("error ");
Serial.println(answer, DEC);
}
}
/* convert2Degrees ( input ) - performs the conversion from input
* parameters in DD°MM.mmm’ notation to DD.dddddd° notation.
*
* Sign '+' is set for positive latitudes/longitudes (North, East)
* Sign '-' is set for negative latitudes/longitudes (South, West)
*
*/
int8_t convert2Degrees(char* input) {
float deg;
float minutes;
boolean neg = false;
//auxiliar variable
char aux[10];
if (input[0] == '-')
{
neg = true;
strcpy(aux, strtok(input + 1, "."));
}
else
{
strcpy(aux, strtok(input, "."));
}
// convert string to integer and add it to final float variable
deg = atof(aux);
strcpy(aux, strtok(NULL, '\0'));
minutes = atof(aux);
minutes /= 1000000;
if (deg < 100)
{
minutes += deg;
deg = 0;
}
else
{
minutes += int(deg) % 100;
deg = int(deg) / 100;
}
// add minutes to degrees
deg = deg + minutes / 60;
if (neg == true)
{
deg *= -1.0;
}
neg = false;
if ( deg < 0 ) {
neg = true;
deg *= -1;
}
float numeroFloat = deg;
int parteEntera[10];
int cifra;
long numero = (long)numeroFloat;
int size = 0;
while (1) {
size = size + 1;
cifra = numero % 10;
numero = numero / 10;
parteEntera[size - 1] = cifra;
if (numero == 0) {
break;
}
}
int indice = 0;
if ( neg ) {
indice++;
input[0] = '-';
}
for (int i = size - 1; i >= 0; i--)
{
input[indice] = parteEntera[i] + '0';
indice++;
}
input[indice] = '.';
indice++;
numeroFloat = (numeroFloat - (int)numeroFloat);
for (int i = 1; i <= 6 ; i++)
{
numeroFloat = numeroFloat * 10;
cifra = (long)numeroFloat;
numeroFloat = numeroFloat - cifra;
input[indice] = char(cifra) + 48;
indice++;
}
input[indice] = '\0';
}
Raspberry Pi:
Code:
/*
* GPRS+GPS Quadband Module (SIM908)
*
* Copyright (C) Libelium Comunicaciones Distribuidas S.L.
* http://www.libelium.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* a
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*
* Version: 1.0
* Design: David Gascón
* Implementation: Marcos Martínez
*/
//Include arduPi library
#include "arduPi.h"
int8_t sendATcommand(const char* ATcommand, const char* expected_answer, unsigned int timeout);
void power_on();
void sendSMS();
int8_t start_GPS();
void measure_temperature();
int8_t get_GPS();
int8_t convert2Degrees(char* input);
//Enter here you data
const char pin_number[] = "****"; // Write the pin number of the SIM card
const char phone_number[] = "*********"; // Write the number to send the SMS
int onModulePin = 2;
char aux_string[30];
int8_t answer;
int flag = 0;
float temperature = 0.0; // Stores the calculated temperature
int sample; // Counts through ADC samples
float ten_samples = 0.0; // Stores sum of 10 samples
char frame[200];
char latitude[15];
char longitude[15];
char altitude[6];
char date[16];
char satellites[3];
char speedOTG[10];
char course[10];
void setup() {
pinMode(onModulePin, OUTPUT);
Serial.begin(115200);
printf("Starting...\n");
power_on(); // Powering the module
delay(5000);
//sets the PIN code
sprintf(aux_string, "AT+CPIN=%s", pin_number);
sendATcommand(aux_string, "OK", 2000);
delay(3000);
printf("Connecting to the network...\n");
//Check network registration
while ( (sendATcommand("AT+CREG?", "+CREG: 0,1", 1000) ||
sendATcommand("AT+CREG?", "+CREG: 0,5", 1000)) == 0 );
sendATcommand("AT+CLIP=1", "OK", 1000);
while ( start_GPS() == 0);
printf("Connected to the network!!\n");
delay(1000);
while (Serial.available() != 0)
{
Serial.read();
}
}
void loop() {
measure_temperature();
//Send SMS if temperature is 0 or below 0
//Only send one SMS because of the flag, to reset the flag, reset Arduino
if (temperature <= 0.0 && flag == 0) {
get_GPS();
delay(500);
sendSMS();
delay(100);
flag++;
}
}
/************************************************************************
**** Definition of functions ****
************************************************************************/
void measure_temperature()
{
// take 10 samples from the MCP9700
for (sample = 0; sample < 10; sample++) {
// convert A0 value to temperature
temperature = ((float)analogRead(0) * 5.0 / 1024.0) - 0.5;
temperature = temperature / 0.01;
// sample every 0.1 seconds
delay(100);
// sum of all samples
ten_samples = ten_samples + temperature;
}
// get the average value of 10 temperatures
temperature = ten_samples / 10.0;
// send temperature out of serial port
printf("temperature: %fºC\n", temperature);
ten_samples = 0.0;
}
void power_on() {
uint8_t answer = 0;
// checks if the module is started
answer = sendATcommand("AT", "OK", 2000);
if (answer == 0)
{
// power on pulse
digitalWrite(onModulePin, HIGH);
delay(3000);
digitalWrite(onModulePin, LOW);
// waits for an answer from the module
while (answer == 0) { // Send AT every two seconds and wait for the answer
answer = sendATcommand("AT", "OK", 2000);
}
}
}
int8_t sendATcommand(const char* ATcommand, const char* expected_answer, unsigned int timeout){
uint8_t x=0, answer=0;
char response[100];
unsigned long previous;
memset(response, '\0', 100); // Initialize the string
delay(100);
while( Serial.available() > 0) Serial.read(); // Clean the input buffer
Serial.println(ATcommand); // Send the AT command
x = 0;
previous = millis();
// this loop waits for the answer
do{
if(Serial.available() != 0){
// if there are data in the UART input buffer, reads it and checks for the asnwer
response[x] = Serial.read();
printf("%c",response[x]);
x++;
// check if the desired answer is in the response of the module
if (strstr(response, expected_answer) != NULL)
{
printf("\n");
answer = 1;
}
}
}
// Waits for the asnwer with time out
while((answer == 0) && ((millis() - previous) < timeout));
return answer;
}
int8_t start_GPS() {
unsigned long previous;
previous = millis();
// starts the GPS
sendATcommand("AT+CGPSPWR=1", "OK", 2000);
sendATcommand("AT+CGPSRST=0", "OK", 2000);
// waits for fix GPS
while (( (sendATcommand("AT+CGPSSTATUS?", "2D Fix", 5000) ||
sendATcommand("AT+CGPSSTATUS?", "3D Fix", 5000)) == 0 ) &&
((millis() - previous) < 90000));
if ((millis() - previous) < 90000)
{
return 1;
}
else
{
return 0;
}
}
int8_t get_GPS() {
int8_t answer,counter;
long previous;
// First get the NMEA string
// Clean the input buffer
while ( Serial.available() > 0) Serial.read();
delay(100);
// request Basic string
sendATcommand("AT+CGPSINF=0", "AT+CGPSINF=0\r\n\r\n", 2000);
counter = 0;
answer = 0;
memset(frame, '\0', 200); // Initialize the string
previous = millis();
// this loop waits for the NMEA string
do {
if (Serial.available() != 0) {
frame[counter] = Serial.read();
counter++;
// check if the desired answer is in the response of the module
if (strstr(frame, "OK") != NULL)
{
answer = 1;
}
}
// Waits for the asnwer with time out
}
while ((answer == 0) && ((millis() - previous) < 2000));
frame[counter - 3] = '\0';
// Parses the string
strtok(frame, ",");
strcpy(longitude, strtok(NULL, ",")); // Gets longitude
strcpy(latitude, strtok(NULL, ",")); // Gets latitude
strcpy(altitude, strtok(NULL, ".")); // Gets altitude
strtok(NULL, ",");
strcpy(date, strtok(NULL, ".")); // Gets date
strtok(NULL, ",");
strtok(NULL, ",");
strcpy(satellites, strtok(NULL, ",")); // Gets satellites
strcpy(speedOTG, strtok(NULL, ",")); // Gets speed over ground. Unit is knots.
strcpy(course, strtok(NULL, "\r")); // Gets course
convert2Degrees(latitude);
convert2Degrees(longitude);
return answer;
}
void sendSMS() {
printf("Setting SMS mode...\n");
sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text
printf("Sending SMS\n");
sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number);
answer = sendATcommand(aux_string, ">", 2000); // send the SMS number
if (answer == 1)
{
Serial.print("Help me! My temperature is critical. Find me in ");
Serial.print("Latitude: ");
int i = 0;
while (latitude[i] != 0) {
Serial.print(latitude[i]);
i++;
}
Serial.print(" / Longitude: ");
i = 0;
while (longitude[i] != 0) {
Serial.print(longitude[i]);
i++;
}
Serial.write(0x1A);
answer = sendATcommand("", "OK", 20000);
if (answer == 1)
{
printf("Sent \n");
}
else
{
printf("error \n");
}
}
else
{
printf("error %i\n",answer);
}
}
/* convert2Degrees ( input ) - performs the conversion from input
* parameters in DD°MM.mmm’ notation to DD.dddddd° notation.
*
* Sign '+' is set for positive latitudes/longitudes (North, East)
* Sign '-' is set for negative latitudes/longitudes (South, West)
*
*/
int8_t convert2Degrees(char* input) {
float deg;
float minutes;
boolean neg = false;
//auxiliar variable
char aux[10];
memset(aux, '\0', sizeof(aux));
if (input[0] == '-')
{
neg = true;
strncpy(aux, input+1, strchr(input, '.') - input - 1);
}
else
{
strncpy(aux, input, strchr(input, '.') - input );
}
// convert string to integer and add it to final float variable
deg = atof(aux);
memset(aux, '\0', sizeof(aux));
strncpy(aux, strchr(input, '.')+1, strlen(input) - (strchr(input, '.') - input) + 1);
minutes = atof(aux);
minutes /= 1000000;
if (deg < 100)
{
minutes += deg;
deg = 0;
}
else
{
minutes += int(deg) % 100;
deg = int(deg) / 100;
}
// add minutes to degrees
deg = deg + minutes / 60;
if (neg == true)
{
deg *= -1.0;
}
neg = false;
if ( deg < 0 ) {
neg = true;
deg *= -1;
}
float numeroFloat = deg;
int parteEntera[10];
int cifra;
long numero = (long)numeroFloat;
int size = 0;
while (1) {
size = size + 1;
cifra = numero % 10;
numero = numero / 10;
parteEntera[size - 1] = cifra;
if (numero == 0) {
break;
}
}
int indice = 0;
if ( neg ) {
indice++;
input[0] = '-';
}
for (int i = size - 1; i >= 0; i--)
{
input[indice] = parteEntera[i] + '0';
indice++;
}
input[indice] = '.';
indice++;
numeroFloat = (numeroFloat - (int)numeroFloat);
for (int i = 1; i <= 6 ; i++)
{
numeroFloat = numeroFloat * 10;
cifra = (long)numeroFloat;
numeroFloat = numeroFloat - cifra;
input[indice] = char(cifra) + 48;
indice++;
}
input[indice] = '\0';
}
int main (){
setup();
while(1){
loop();
}
return (0);
}
Intel Galileo:
Code:
/*
* GPRS+GPS Quadband Module (SIM908)
*
* Copyright (C) Libelium Comunicaciones Distribuidas S.L.
* http://www.libelium.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* a
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*
* Version: 1.0
* Design: David Gascón
* Implementation: Jorge Casanova, Luis Martín
*/
//Enter here you data
const char pin_number[] = "****"; // Write the pin number of the SIM card
const char phone_number[] = "*********"; // Write the number to send the SMS
int onModulePin = 2;
char aux_string[30];
int8_t answer;
int flag = 0;
float temperature = 0.0; // Stores the calculated temperature
int sample; // Counts through ADC samples
float ten_samples = 0.0; // Stores sum of 10 samples
char frame[200];
char latitude[15];
char longitude[15];
char altitude[6];
char date[16];
char satellites[3];
char speedOTG[10];
char course[10];
void setup() {
pinMode(onModulePin, OUTPUT);
Serial.begin(115200);
Serial1.begin(115200);
Serial.println("Starting...");
power_on(); // Powering the module
delay(5000);
//sets the PIN code
sprintf(aux_string, "AT+CPIN=%s", pin_number);
sendATcommand(aux_string, "OK", 2000);
delay(3000);
Serial.println("Connecting to the network...");
//Check network registration
while ( (sendATcommand("AT+CREG?", "+CREG: 0,1", 1000) ||
sendATcommand("AT+CREG?", "+CREG: 0,5", 1000)) == 0 );
sendATcommand("AT+CLIP=1", "OK", 1000);
while ( start_GPS() == 0);
Serial.println("Connected to the network!!");
delay(1000);
while (Serial1.available() != 0)
{
Serial1.read();
}
}
void loop() {
measure_temperature();
//Send SMS if temperature is 0 or below 0
//Only send one SMS because of the flag, to reset the flag, reset Arduino
if (temperature <= 0 && flag == 0) {
get_GPS();
delay(500);
sendSMS();
delay(100);
flag++;
}
}
/************************************************************************
**** Definition of functions ****
************************************************************************/
void measure_temperature()
{
// take 10 samples from the MCP9700
for (sample = 0; sample < 10; sample++) {
// convert A0 value to temperature
temperature = ((float)analogRead(A0) * 5.0 / 1024.0) - 0.5;
temperature = temperature / 0.01;
temperature = temperature - 5.3;
// sample every 0.1 seconds
delay(100);
// sum of all samples
ten_samples = ten_samples + temperature;
}
// get the average value of 10 temperatures
temperature = ten_samples / 10.0;
// send temperature out of serial port
Serial.print(temperature);
Serial.println(" deg. C");
ten_samples = 0.0;
}
void power_on() {
uint8_t answer = 0;
// checks if the module is started
answer = sendATcommand("AT", "OK", 2000);
if (answer == 0)
{
// power on pulse
digitalWrite(onModulePin, HIGH);
delay(3000);
digitalWrite(onModulePin, LOW);
// waits for an answer from the module
while (answer == 0) { // Send AT every two seconds and wait for the answer
answer = sendATcommand("AT", "OK", 2000);
}
}
}
int8_t sendATcommand(char* ATcommand, char* expected_answer, unsigned int timeout) {
uint8_t x = 0, answer = 0;
char response[100];
unsigned long previous;
memset(response, '\0', 100); // Initialice the string
delay(100);
while ( Serial1.available() > 0) Serial1.read(); // Clean the input buffer
if (ATcommand[0] != '\0')
{
Serial1.println(ATcommand); // Send the AT command
}
x = 0;
previous = millis();
// this loop waits for the answer
do {
if (Serial1.available() != 0) { // if there are data in the UART input buffer, reads it and checks for the asnwer
response[x] = Serial1.read();
Serial.print(response[x]);
x++;
if (strstr(response, expected_answer) != NULL) // check if the desired answer (OK) is in the response of the module
{
answer = 1;
}
}
} while ((answer == 0) && ((millis() - previous) < timeout)); // Waits for the asnwer with time out
return answer;
}
int8_t start_GPS() {
unsigned long previous;
previous = millis();
// starts the GPS
sendATcommand("AT+CGPSPWR=1", "OK", 2000);
sendATcommand("AT+CGPSRST=0", "OK", 2000);
// waits for fix GPS
while (( (sendATcommand("AT+CGPSSTATUS?", "2D Fix", 5000) ||
sendATcommand("AT+CGPSSTATUS?", "3D Fix", 5000)) == 0 ) &&
((millis() - previous) < 90000));
if ((millis() - previous) < 90000)
{
return 1;
}
else
{
return 0;
}
}
int8_t get_GPS() {
int8_t counter, answer;
long previous;
// First get the NMEA string
// Clean the input buffer
while ( Serial1.available() > 0) Serial1.read();
// request Basic string
sendATcommand("AT+CGPSINF=0", "AT+CGPSINF=0\r\n\r\n", 2000);
counter = 0;
answer = 0;
memset(frame, '\0', 100); // Initialize the string
previous = millis();
// this loop waits for the NMEA string
do {
if (Serial1.available() != 0) {
frame[counter] = Serial1.read();
counter++;
// check if the desired answer is in the response of the module
if (strstr(frame, "OK") != NULL)
{
answer = 1;
}
}
// Waits for the asnwer with time out
}
while ((answer == 0) && ((millis() - previous) < 2000));
frame[counter - 3] = '\0';
// Parses the string
strtok(frame, ",");
strcpy(longitude, strtok(NULL, ",")); // Gets longitude
strcpy(latitude, strtok(NULL, ",")); // Gets latitude
strcpy(altitude, strtok(NULL, ".")); // Gets altitude
strtok(NULL, ",");
strcpy(date, strtok(NULL, ".")); // Gets date
strtok(NULL, ",");
strtok(NULL, ",");
strcpy(satellites, strtok(NULL, ",")); // Gets satellites
strcpy(speedOTG, strtok(NULL, ",")); // Gets speed over ground. Unit is knots.
strcpy(course, strtok(NULL, "\r")); // Gets course
convert2Degrees(latitude);
convert2Degrees(longitude);
return answer;
}
void sendSMS() {
Serial.print("Setting SMS mode...");
sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text
Serial.println("Sending SMS");
sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number);
answer = sendATcommand(aux_string, ">", 2000); // send the SMS number
if (answer == 1)
{
Serial.print("Help me! My temperature is critical. Find me in:");
Serial.print("Latitude: ");
Serial1.print("Help me! My temperature is critical. Find me in:");
Serial1.print("Latitude: ");
int i = 0;
while (latitude[i] != 0) {
Serial.print(latitude[i]);
Serial1.print(latitude[i]);
i++;
}
Serial.print(" / Longitude: ");
Serial1.print(" / Longitude: ");
i = 0;
while (longitude[i] != 0) {
Serial.print(longitude[i]);
Serial1.print(longitude[i]);
i++;
}
Serial1.write(0x1A);
answer = sendATcommand("", "OK", 20000);
if (answer == 1)
{
Serial.print("Sent ");
}
else
{
Serial.print("error ");
}
}
else
{
Serial.print("error ");
Serial.println(answer, DEC);
}
}
/* convert2Degrees ( input ) - performs the conversion from input
* parameters in DD°MM.mmm’ notation to DD.dddddd° notation.
*
* Sign '+' is set for positive latitudes/longitudes (North, East)
* Sign '-' is set for negative latitudes/longitudes (South, West)
*
*/
int8_t convert2Degrees(char* input) {
float deg;
float minutes;
boolean neg = false;
//auxiliar variable
char aux[10];
if (input[0] == '-')
{
neg = true;
strcpy(aux, strtok(input + 1, "."));
}
else
{
strcpy(aux, strtok(input, "."));
}
// convert string to integer and add it to final float variable
deg = atof(aux);
strcpy(aux, strtok(NULL, "\0"));
minutes = atof(aux);
minutes /= 1000000;
if (deg < 100)
{
minutes += deg;
deg = 0;
}
else
{
minutes += int(deg) % 100;
deg = int(deg) / 100;
}
// add minutes to degrees
deg = deg + minutes / 60;
if (neg == true)
{
deg *= -1.0;
}
neg = false;
if ( deg < 0 ) {
neg = true;
deg *= -1;
}
float numeroFloat = deg;
int parteEntera[10];
int cifra;
long numero = (long)numeroFloat;
int size = 0;
while (1) {
size = size + 1;
cifra = numero % 10;
numero = numero / 10;
parteEntera[size - 1] = cifra;
if (numero == 0) {
break;
}
}
int indice = 0;
if ( neg ) {
indice++;
input[0] = '-';
}
for (int i = size - 1; i >= 0; i--)
{
input[indice] = parteEntera[i] + '0';
indice++;
}
input[indice] = '.';
indice++;
numeroFloat = (numeroFloat - (int)numeroFloat);
for (int i = 1; i <= 6 ; i++)
{
numeroFloat = numeroFloat * 10;
cifra = (long)numeroFloat;
numeroFloat = numeroFloat - cifra;
input[indice] = char(cifra) + 48;
indice++;
}
input[indice] = '\0';
}
Links and Documentation
Related Tutorials
- Geolocation Tracker (GPRS + GPS) with SIM908 over Arduino and Raspberry Pi
- How to Make a Call with Push Buttons Using Tracking Kit (GPRS + GPS)
- How to Send a Temperature Emergency SMS Using Tracking Kit (GPRS + GPS)
- How to Control a Servo with Text Messages Using Tracking Kit (GPRS + GPS)
- How to Display Latitude and Longitude on an LCD Using Tracking Kit (GPRS + GPS)
Datasheets and Manuals
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