This tutorial allows the user to get temperature and control LEDs status sending text messages with the mobile phone. Depending on the text message received by the module, you will be able to turn ON and OFF two LEDs and get the temperature with a sensor.
Ingredients:
Preparation Time: 30 minutes
Buy nowThis 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/GSM QUADBAND MODULE (SIM900) Shield, consult the main tutorial.
Connect the GPRS antenna to the shield and then, connect the shield to Arduino or to Raspberry Pi connection bridge. Connect the LEDs, the resistors and the 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. Then, connect digital pin 9 and 10 to one leg of each resistor. That other leg of the resistor is connected to the cathode (negative leg) of the LED. The other legs of the LEDs (anode) connect to VCC supply. Place the temperature sensor with the flat part looking down like the diagram. Connect the right leg of the sensor to GND and the left to 5 volt. Connect the central leg to the first pin at bottom left of the shield (Analog 0).
Arduino:
/* * GPRS/GSM Quadband Module (SIM900) * * 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. * * 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: Luis Miguel Martà */ #define HEATING 9 #define COOLING 10 //Temperature control int cnt; //counter float tdegrees; // int sensorPin = A0; // input for the thermistor int sensorValue = 0; // voltage value from voltage divider int8_t answer; int x; int onModulePin = 2; char SMS[200]; char aux_string[30]; char phone_number[] = "*********"; //phone number to send SMS char received[200]; char message1[] = {"COOLING ON"}; char message2[] = {"COOLING OFF"}; char message3[] = {"HEATING ON"}; char message4[] = {"HEATING OFF"}; char message5[] = {"TEMP"}; char message6[] = {"Temp: "}; char coma[] = {","}; char deg[] = {" Celsius degrees"}; void setup() { pinMode(onModulePin, OUTPUT); Serial.begin(115200); Serial.println("Starting..."); power_on(); delay(3000); memset(SMS, 0, sizeof(SMS)); pinMode(COOLING, OUTPUT); pinMode(HEATING, OUTPUT); //LED's are controlled with negative logic digitalWrite(COOLING, LOW); digitalWrite(HEATING, LOW); Serial.println("Setting SMS mode..."); sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text delay(500); sendATcommand("AT+CNMI=3,2,0,0", "OK", 1000); //configure new message reception digitalWrite(COOLING, HIGH); digitalWrite(HEATING, HIGH); } void loop() { //wait for the start character if (Serial.read() == '+') { //read all data for (byte i = 0; i < 200; i++) { delay(1); received[i] = Serial.read(); } byte z = 47; //here start the SMS, data before this point are date and time while (char(received[z]) != '\n') { SMS[z - 47] = received[z]; Serial.print(SMS[z - 47]); z++; } byte message = checkSMS(); switch (message) { case 0: Serial.println("Unknown message!!"); break; case 1: Serial.println("Cooling on!"); digitalWrite(COOLING, LOW); break; case 2: Serial.println("Cooling off!"); digitalWrite(COOLING, HIGH); break; case 3: Serial.println("Heating on!"); digitalWrite(HEATING, LOW); break; case 4: Serial.println("Heating off!"); digitalWrite(HEATING, HIGH); break; case 5: get_temp(); Serial.println("Sending temp!"); sendSMS(message6); break; } } } 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 Serial.println(ATcommand); // Send the AT command x = 0; previous = millis(); // this loop waits for the answer do { // if there are data in the UART input buffer, reads it and checks for the asnwer if (Serial.available() != 0) { response[x] = Serial.read(); x++; // check if the desired answer is in the response of the module if (strstr(response, expected_answer) != NULL) { answer = 1; } } // Waits for the asnwer with time out } while ((answer == 0) && ((millis() - previous) < timeout)); return answer; } void get_temp() { tdegrees = analogRead(0)*5/1024.0; tdegrees = tdegrees - 0.5; tdegrees = tdegrees / 0.01; //print all through serial Serial.println("Temperature:"); Serial.print(" "); Serial.print(tdegrees); Serial.print("C"); } //this function compares the SMS received with messages declared to know what to do byte checkSMS() { for (byte i = 0; i < sizeof(message1) - 1; i++) { if (message1[i] == SMS[i]) { if (i == sizeof(message1) - 2) return 1; } else i = sizeof(message1); } for (byte i = 0; i < sizeof(message2) - 1; i++) { if (message2[i] == SMS[i]) { if (i == sizeof(message2) - 2) return 2; } else i = sizeof(message2); } for (byte i = 0; i < sizeof(message3) - 1; i++) { if (message3[i] == SMS[i]) { if (i == sizeof(message3) - 2) return 3; } else i = sizeof(message3); } for (byte i = 0; i < sizeof(message4) - 1; i++) { if (message4[i] == SMS[i]) { if (i == sizeof(message4) - 2) return 4; } else i = sizeof(message4); } for (byte i = 0; i < sizeof(message5) - 1; i++) { if (message5[i] == SMS[i]) { if (i == sizeof(message5) - 2) return 5; } else i = sizeof(message5); } return 0; } void sendSMS(char *mess) { sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number); //builds the string to send to the module answer = sendATcommand(aux_string, ">", 2000); // send the SMS number if (answer == 1) { char taux[15]; dtostrf(tdegrees,5,2,taux); sprintf(aux_string, "%s%s%s", mess, taux, deg); //builds the string to send as an SMS Serial.println(aux_string); 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); } }
Raspberry Pi:
/* * GPRS/GSM Quadband Module (SIM900) * * 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. * * 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 Martinez */ #include "arduPi.h" #define HEATING 9 #define COOLING 10 //Temperature control int cnt; //counter float tdegrees; // int sensorPin = 0; // input for the thermistor int sensorValue = 0; // voltage value from voltage divider int8_t answer; int x; int onModulePin = 2; char SMS[200]; char aux_string[30]; char phone_number[] = "*******"; //phone number to send SMS char received[200]; char message1[] = {"COOLING ON"}; char message2[] = {"COOLING OFF"}; char message3[] = {"HEATING ON"}; char message4[] = {"HEATING OFF"}; char message5[] = {"TEMP"}; char message6[] = {"Temp: "}; char coma[] = {","}; char deg[] = {" Celsius degrees"}; void power_on(); int8_t sendATcommand(const char* ATcommand, const char* expected_answer, unsigned int timeout); void get_temp(); byte checkSMS(); void sendSMS( char *mess); void setup() { pinMode(onModulePin, OUTPUT); Serial.begin(115200); printf("Starting...\n"); power_on(); delay(3000); memset(SMS, 0, sizeof(SMS)); pinMode(COOLING, OUTPUT); pinMode(HEATING, OUTPUT); //LED's are controlled with negative logic digitalWrite(COOLING, LOW); digitalWrite(HEATING, LOW); printf("Setting SMS mode...\n"); sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text delay(500); sendATcommand("AT+CNMI=3,2,0,0", "OK", 1000); //configure new message reception digitalWrite(COOLING, HIGH); digitalWrite(HEATING, HIGH); printf("Waiting for a SMS...\n"); } void loop() { //wait for the start character if(Serial.read() == '+'){ //read all data byte i=0; while(Serial.available()>0){ delay(1); received[i] = Serial.read(); i++; } byte z = 47; //here start the SMS, data before this point are date and time while (char(received[z]) != '\n') { SMS[z - 47] = received[z]; z++; } printf("SMS received: %s\n", SMS); byte message = checkSMS(); switch (message) { case 0: printf("Unknown message!!\n"); break; case 1: printf("Cooling on!\n"); digitalWrite(COOLING, LOW); break; case 2: printf("Cooling off!\n"); digitalWrite(COOLING, HIGH); break; case 3: printf("Heating on!\n"); digitalWrite(HEATING, LOW); break; case 4: printf("Heating off!\n"); digitalWrite(HEATING, HIGH); break; case 5: get_temp(); printf("Sending temp!\n"); sendSMS(message6); break; } } delay(1000); } 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); // Initialice the string delay(100); Serial.println(ATcommand); // Send the AT command x = 0; previous = millis(); // this loop waits for the answer do { // if there are data in the UART input buffer, reads it and checks for the asnwer if (Serial.available() != 0) { 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; } void get_temp() { tdegrees = analogRead(0)*5/1024.0; tdegrees = tdegrees - 0.5; tdegrees = tdegrees / 0.01; //print all through serial printf("Temperature: %fºC\n", tdegrees); } //this function compares the SMS received with messages declared to know what to do byte checkSMS() { for (byte i = 0; i < sizeof(message1) - 1; i++) { if (message1[i] == SMS[i]) { if (i == sizeof(message1) - 2) return 1; } else i = sizeof(message1); } for (byte i = 0; i < sizeof(message2) - 1; i++) { if (message2[i] == SMS[i]) { if (i == sizeof(message2) - 2) return 2; } else i = sizeof(message2); } for (byte i = 0; i < sizeof(message3) - 1; i++) { if (message3[i] == SMS[i]) { if (i == sizeof(message3) - 2) return 3; } else i = sizeof(message3); } for (byte i = 0; i < sizeof(message4) - 1; i++) { if (message4[i] == SMS[i]) { if (i == sizeof(message4) - 2) return 4; } else i = sizeof(message4); } for (byte i = 0; i < sizeof(message5) - 1; i++) { if (message5[i] == SMS[i]) { if (i == sizeof(message5) - 2) return 5; } else i = sizeof(message5); } return 0; } void sendSMS( char *mess) { sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number); //builds the string to send to the module answer = sendATcommand(aux_string, ">", 2000); // send the SMS number if (answer == 1) { //char taux[15]; //dtostrf(tdegrees,5,2,taux); sprintf(aux_string, "%s%f%s", mess, tdegrees, deg); //builds the string to send as an SMS Serial.println(aux_string); Serial.write(0x1A); answer = sendATcommand("", "OK", 20000); if (answer == 1) { printf("Sent \n"); } else { printf("error \n"); } } else { printf("error %d\n", answer); } } int main (){ setup(); while(1){ loop(); } return (0); }
Intel Galileo:
/* * GPRS/GSM Quadband Module (SIM900) * * 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. * * 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 Martin */ #define HEATING 9 #define COOLING 10 //Temperature control int cnt; //counter float tdegrees; // int sensorPin = A0; // input for the thermistor int sensorValue = 0; // voltage value from voltage divider int8_t answer; int x; int onModulePin = 2; char SMS[200]; char aux_string[30]; char phone_number[] = "*********"; //phone number to send SMS char received[200]; char message1[] = {"COOLING ON"}; char message2[] = {"COOLING OFF"}; char message3[] = {"HEATING ON"}; char message4[] = {"HEATING OFF"}; char message5[] = {"TEMP"}; char message6[] = {"Temp: "}; char coma[] = {","}; char deg[] = {" Celsius degrees"}; void setup() { pinMode(onModulePin, OUTPUT); Serial.begin(115200); Serial1.begin(115200); Serial.println("Starting..."); power_on(); delay(3000); memset(SMS, 0, sizeof(SMS)); pinMode(COOLING, OUTPUT); pinMode(HEATING, OUTPUT); //LED's are controlled with negative logic digitalWrite(COOLING, LOW); digitalWrite(HEATING, LOW); Serial.println("Setting SMS mode..."); sendATcommand("AT+CMGF=1", "OK", 1000); // sets the SMS mode to text delay(500); sendATcommand("AT+CNMI=3,2,0,0", "OK", 1000); //configure new message reception digitalWrite(COOLING, HIGH); digitalWrite(HEATING, HIGH); } void loop() { //wait for the start character if (Serial1.read() == '+') { //read all data for (byte i = 0; i < 200; i++) { delay(1); received[i] = Serial1.read(); } byte z = 47; //here start the SMS, data before this point are date and time while (char(received[z]) != '\n') { SMS[z - 47] = received[z]; Serial.print(SMS[z - 47]); z++; } byte message = checkSMS(); switch (message) { case 0: Serial.println("Unknown message!!"); break; case 1: Serial.println("Cooling on!"); digitalWrite(COOLING, LOW); break; case 2: Serial.println("Cooling off!"); digitalWrite(COOLING, HIGH); break; case 3: Serial.println("Heating on!"); digitalWrite(HEATING, LOW); break; case 4: Serial.println("Heating off!"); digitalWrite(HEATING, HIGH); break; case 5: get_temp(); Serial.println("Sending temp!"); sendSMS(message6); break; } } } 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 Serial1.println(ATcommand); // Send the AT command x = 0; previous = millis(); // this loop waits for the answer do { // if there are data in the UART input buffer, reads it and checks for the asnwer if (Serial1.available() != 0) { response[x] = Serial1.read(); x++; // check if the desired answer is in the response of the module if (strstr(response, expected_answer) != NULL) { answer = 1; } } // Waits for the asnwer with time out } while ((answer == 0) && ((millis() - previous) < timeout)); return answer; } void get_temp() { tdegrees = analogRead(0)*5/1024.0; tdegrees = tdegrees - 0.5; tdegrees = tdegrees / 0.01; //print all through serial Serial.println("Temperature:"); Serial.print(" "); Serial.print(tdegrees); Serial.print("C"); } //this function compares the SMS received with messages declared to know what to do byte checkSMS() { for (byte i = 0; i < sizeof(message1) - 1; i++) { if (message1[i] == SMS[i]) { if (i == sizeof(message1) - 2) return 1; } else i = sizeof(message1); } for (byte i = 0; i < sizeof(message2) - 1; i++) { if (message2[i] == SMS[i]) { if (i == sizeof(message2) - 2) return 2; } else i = sizeof(message2); } for (byte i = 0; i < sizeof(message3) - 1; i++) { if (message3[i] == SMS[i]) { if (i == sizeof(message3) - 2) return 3; } else i = sizeof(message3); } for (byte i = 0; i < sizeof(message4) - 1; i++) { if (message4[i] == SMS[i]) { if (i == sizeof(message4) - 2) return 4; } else i = sizeof(message4); } for (byte i = 0; i < sizeof(message5) - 1; i++) { if (message5[i] == SMS[i]) { if (i == sizeof(message5) - 2) return 5; } else i = sizeof(message5); } return 0; } void sendSMS(char *mess) { sprintf(aux_string, "AT+CMGS=\"%s\"", phone_number); //builds the string to send to the module answer = sendATcommand(aux_string, ">", 2000); // send the SMS number if (answer == 1) { //char taux[15]; //dtostrf(tdegrees,5,2,taux); sprintf(aux_string, "%s%f%s", mess, tdegrees, deg); //builds the string to send as an SMS Serial1.println(aux_string); 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); } }
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