This tutorial allows the user to make a call to different numbers. Each button can be assigned to a number and originate a voice call. Pushing other button, you can end that voice call.
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+GPS (SIM908) Shield, consult the main tutorial.
Connect the GPRS antenna to the shield and then, connect the shield to the Arduino or to Raspberry Pi connection bridge. Connect the buttons and the resistors 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 3, 4, 5 and 6 to one leg of each pushbutton. That same leg of the button connects through a pull-down resistor (10kΩ) to ground. The other leg of the button connects to VCC supply.
When the pushbutton is open (unpressed) there is no connection between the two legs of the pushbutton, so the pin is connected to ground (through the pull-down resistor) and reads as LOW, or 0. When the button is closed (pressed), it makes a connection between its two legs, connecting the pin to VCC, so that the pin read as HIGH, or 1.
Arduino:
/* * 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_numberA[] = "*********"; // Write here the number A to call const char phone_numberB[] = "*********"; // Write here the number B to call const char phone_numberC[] = "*********"; // Write here the number C to call //Digital pin definitions int onModulePin = 2; int buttonA = 3; int buttonB = 4; int buttonC = 5; int endbutton = 6; int8_t answer; char aux_string[30]; void setup() { pinMode(onModulePin, OUTPUT); pinMode(buttonA, INPUT); pinMode(buttonB, INPUT); pinMode(buttonC, INPUT); pinMode(endbutton, INPUT); Serial.begin(115200); Serial.println("Starting..."); power_on(); // Powering the module delay(3000); //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 ); Serial.println("Connected to the network!!"); delay(1000); Serial.println("Press a button to call"); } void loop() { //If button A is pressed call to number A if (digitalRead(buttonA) == 1) { sprintf(aux_string, "ATD%s;", phone_numberA); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button B is pressed call to number B if (digitalRead(buttonB) == 1) { sprintf(aux_string, "ATD%s;", phone_numberB); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button C is pressed call to number C if (digitalRead(buttonC) == 1) { sprintf(aux_string, "ATD%s;", phone_numberC); //calls to number C sendATcommand(aux_string, "OK", 10000); delay(100); } //If endbutton is pressed disconnects the existing call if (digitalRead(endbutton) == 1) { Serial.println("ATH"); delay(100); } } /************************************************************************ **** Definition of functions **** ************************************************************************/ 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); // 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(); 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; }
Raspberry Pi:
/* * 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 MartÃnez */ //Include arduPi library #include "arduPi.h" int8_t sendATcommand(const char* ATcommand, const char* expected_answer, unsigned int timeout); void power_on(); //Enter here you data const char pin_number[] = "****"; // Write the pin number of the SIM card const char phone_numberA[] = "*********"; // Write here the number A to call const char phone_numberB[] = "*********"; // Write here the number B to call const char phone_numberC[] = "*********"; // Write here the number C to call //Digital pin definitions int onModulePin = 2; int buttonA = 3; int buttonB = 4; int buttonC = 5; int endbutton = 6; int8_t answer; char aux_string[30]; void setup() { pinMode(onModulePin, OUTPUT); pinMode(buttonA, INPUT); pinMode(buttonB, INPUT); pinMode(buttonC, INPUT); pinMode(endbutton, INPUT); Serial.begin(115200); printf("Starting...\n"); power_on(); // Powering the module delay(3000); //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 ); printf("Connected to the network!!\n"); delay(1000); printf("Press a button to call\n"); } void loop() { //If button A is pressed call to number A if (digitalRead(buttonA) == 1) { sprintf(aux_string, "ATD%s;", phone_numberA); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button B is pressed call to number B if (digitalRead(buttonB) == 1) { sprintf(aux_string, "ATD%s;", phone_numberB); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button C is pressed call to number C if (digitalRead(buttonC) == 1) { sprintf(aux_string, "ATD%s;", phone_numberC); //calls to number C sendATcommand(aux_string, "OK", 10000); delay(100); } //If endbutton is pressed disconnects the existing call if (digitalRead(endbutton) == 1) { Serial.println("ATH"); printf("Call disconnected\n"); delay(500); } } /************************************************************************ **** Definition of functions **** ************************************************************************/ 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; } int main (){ setup(); while(1){ loop(); } return (0); }
Intel Galileo:
/* * 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 MartÃn */ //Enter here you data const char pin_number[] = "****"; // Write the pin number of the SIM card const char phone_numberA[] = "*********"; // Write here the number A to call const char phone_numberB[] = "*********"; // Write here the number B to call const char phone_numberC[] = "*********"; // Write here the number C to call //Digital pin definitions int onModulePin = 2; int buttonA = 3; int buttonB = 4; int buttonC = 5; int endbutton = 6; int8_t answer; char aux_string[30]; void setup() { pinMode(onModulePin, OUTPUT); pinMode(buttonA, INPUT); pinMode(buttonB, INPUT); pinMode(buttonC, INPUT); pinMode(endbutton, INPUT); Serial.begin(115200); Serial1.begin(115200); Serial.println("Starting..."); power_on(); // Powering the module delay(3000); //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 ); Serial.println("Connected to the network!!"); delay(1000); Serial.println("Press a button to call"); } void loop() { //If button A is pressed call to number A if (digitalRead(buttonA) == 1) { sprintf(aux_string, "ATD%s;", phone_numberA); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button B is pressed call to number B if (digitalRead(buttonB) == 1) { sprintf(aux_string, "ATD%s;", phone_numberB); sendATcommand(aux_string, "OK", 10000); delay(100); } //If button C is pressed call to number C if (digitalRead(buttonC) == 1) { sprintf(aux_string, "ATD%s;", phone_numberC); //calls to number C sendATcommand(aux_string, "OK", 10000); delay(100); } //If endbutton is pressed disconnects the existing call if (digitalRead(endbutton) == 1) { Serial1.println("ATH"); delay(100); } } /************************************************************************ **** Definition of functions **** ************************************************************************/ 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); // Initialize 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 (Serial1.available() != 0) { // if there are data in the UART input buffer, reads it and checks for the asnwer 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; }
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