Added controller for the GSM module. Software power control has been …

…tested. Voice calls and text SMS are awaiting testing and geolocation is to be implemented.

Signed-off-by: Eneko Cruz <[email protected]>

gsm/GSMDevice.cpp

@@ -0,0 +1,156 @@
+#include "GSMDevice.hpp"
+
+using namespace std;
+
+GSMDevice::GSMDevice(){								//Instantiates a GSM device controlled using GPIO 4 (default, software pwr control) and /dev/ttyAMA0 for UART
+	GSMDevice(DEFAULT_GPIO,DEFAULT_UART);
+}
+
+//WARNING: May take up to six seconds
+GSMDevice::GSMDevice(int gpio, string serial){					//Instantiates a GSM device controlled using a GPIO pin (given by GPIO parameter) and a UART port (given by serial){
+	gpionum = gpio;
+	serialPort = serial;
+	InitSerial();
+	InitGSMModule();
+	delay(3000);								//Allow some time for the GSM module to connect to the network.
+}
+
+void GSMDevice::TogglePWR(){							
+	//Toggles the power status of the GSM module. Turns it on if it is off and turns it off if it is on. 
+	//WARNING: Takes 2500 miliseconds to complete
+
+	digitalWrite(gpionum, LOW);						//Spec says that the adafruit FONA expects a 2000ms low pulse
+	delay(2000);
+	digitalWrite(gpionum, HIGH);
+	delay(500);								//Give the module some time to turn on, ensure that when 
+										//function returns the module is operational.
+}
+
+bool GSMDevice::Call(string num){						//Establishes a voice connection with a phone number. The function
+	char *number = new char[num.length() + 1];				//will return when the voice connection is established. Note that
+        strcpy(number, num.c_str());						//having a voice connection does not mean that both parties are
+	char send[20];								//ready to exchange data. In fact, the sender should allow for some
+										//time before transmitting so that the receiver can answer.
+
+	if(strlen(number)>(sizeof(send)/sizeof(char))-(3+1)){			//If the number does not fit into the buffer, reject it, as 
+		if(OPENSTRATOS_GSM_DEBUG_){					//phone numbers (without C.C.) take 9 chars.
+                        printf("[!] Number too long. Aborting call\n");
+        	}
+		return false;
+	}
+	strncpy(send, "ATD", strlen("ATD"));					//AT command preamble: ATD
+  	strncpy(send+3, number, strlen(number));				//Number to dial
+  	int length = strlen(send);
+	send[length] = (char)0x3b;//ascii for semicolon				//Semicolon ending command
+  	send[length+1] = (char)0x0;//terminate string with null byte
+	bool success =  SerialSendCompareResponse(send, "OK");			//Modem will reply OK if a voice connection was established.
+	if(OPENSTRATOS_GSM_DEBUG_ && !success){
+                        printf("[!] ATD+number+; did not reply OK\n");
+        }
+	return success;
+}
+
+bool GSMDevice::AbortCall(){							//Aborts a phone call. No effect if not in a call.
+	bool success = SerialSendCompareResponse("ATH","OK");			//Returns true if call aborted or if not in a call.
+	if(OPENSTRATOS_GSM_DEBUG_ && !success){					//Expecting the modem to return OK.
+                        printf("[!] ATH did not reply OK\n");
+        }
+	return success;
+}
+
+bool GSMDevice::SendSMS(string message, string n){				//Sends a short message to a phone number
+	char *destnum = new char[n.length() + 1];
+        strcpy(destnum, n.c_str());
+	char *messagechar = new char[message.length() + 1];
+        strcpy(messagechar, message.c_str());
+
+	if (SerialSendCompareResponse("AT+CMGF=1", "OK")==false){		//Select SMS message format
+		if(OPENSTRATOS_GSM_DEBUG_){					//Abort if the modem cannot be set to text mode.
+                        printf("[!] AT+CMFG=1 did not reply OK to SMS format selection\n");
+                }
+		return false;
+	}
+
+  	char send[30] = "AT+CMGS=\"";						//SMS command preamble: AT+CMGS="
+  	strncpy(send+9 , destnum, 19);						//SMS destination (actual phone number)
+  	send[strlen(send)] = (char)0x22;//ascii for " (double quote)		//SMS command termination: "
+
+  	if (!SerialSendCompareResponse(send, "> ")){				//Input prompt should be open and expecting text input
+		if(OPENSTRATOS_GSM_DEBUG_){
+                        printf("[!] Failed SMS attempt. SIM800L did not provide input prompt\n");
+                }
+		return false;							//If there is not any input prompt, abort.
+	}
+
+  	serialPrintf(fdesc,messagechar);					//Send message
+  	serialPrintf(fdesc,"\r\n");						//Return
+	FlushSerialInput();							//Module will reply with "+CMGS<length>". Not interested in that, so flush.
+  	return true;								//Message sent.
+}
+
+void GSMDevice::BroadcastGeolocation(string n){					//Tries to perform geolocation and sends coordinates to a phone number via SMS.
+	//TODO
+}
+
+bool GSMDevice::CheckGSMModule(){						//Returns true if module is up and running, false if it is not.
+	if(SerialSendCompareResponse("AT","OK")){				//Probe the SIM800L, see AT command reference for more info.
+		return true;
+	}
+	return false;
+}
+
+bool GSMDevice::InitSerial(){
+	char *cstr = new char[serialPort.length() + 1];
+	strcpy(cstr, serialPort.c_str());
+	fdesc = serialOpen(cstr, UART_BAUDRATE);
+	if(fdesc==-1){								//serialOpen returns a standard linux file descriptor. -1 means failed
+		;/*EXCEPTION: NO SERIAL PORT AVAILABLE*/
+		if(OPENSTRATOS_GSM_DEBUG_){
+			printf("[!] Serial port open error\n");
+		}
+		return false;
+	}
+	return true;
+}
+
+bool GSMDevice::InitGSMModule(){
+	if (wiringPiSetup() == -1){
+		/*EXCEPTION: UNABLE TO ACCESS GPIOS*/;
+		return false;
+	}
+	pinMode(gpionum, OUTPUT);						//Set GPIO as digital output
+	digitalWrite(gpionum, HIGH);						//Set to high so that GSM module stays in standby until TogglePWR is called
+	return true;
+}
+
+bool GSMDevice::SerialSendCompareResponse(char *send, char *expected){
+	SerialSendRead(send);							//Send a string via serial.
+  	return (strcmp(serialin, expected) == 0);				//Compare what got placed in serialin with the expected answer
+}
+
+uint16_t GSMDevice::SerialSendRead(char *send) {
+	FlushSerialInput();
+	if(OPENSTRATOS_GSM_DEBUG_){
+                        printf("[i] Sending: %s", send);
+        }
+	serialPrintf(fdesc, send);
+	uint16_t readlength = SerialReadLine();
+	if(OPENSTRATOS_GSM_DEBUG_){
+                        printf("[i] Received: %s\n", serialin);
+        }
+	return readlength;
+}
+
+void GSMDevice::FlushSerialInput() {
+	serialFlush(fdesc);
+}
+
+uint16_t GSMDevice::SerialReadLine() {
+ 	uint16_t i = 0;
+	while(serialDataAvail(fdesc)&&i<254) {
+    		char c =  serialGetchar(fdesc);
+    		serialin[i++] = c;
+  	}
+  	serialin[i] = 0x0;
+  	return i;
+}

gsm/GSMDevice.hpp

@@ -0,0 +1,64 @@
+#ifndef OPENSTRATOS_WIRINGPI_H_
+#define OPENSTRATOS_WIRINGPI_H_
+#include <wiringPi.h>
+#endif
+
+#ifndef OPENSTRATOS_WIRINGSERIAL_H
+#define OPENSTRATOS_WIRINGSERIAL_H
+#include <wiringSerial.h>
+#endif
+
+#ifndef OPENSTRATOS_GSM_INCLUDE_ALL_
+#define OPENSTRATOS_GSM_INCLUDE_ALL_
+#include <string.h>
+#include <stdlib.h>
+#include <iostream>
+#include <stdint.h>
+#include <algorithm>
+#include <stdio.h>
+#endif
+
+#define OPENSTRATOS_GSM_DEBUG_ 0
+//0 = disable debug mode
+//1 = enable debug mode
+
+#ifndef OPENSTRATOS_GSM_GSMDEVICE_CLASS_
+#define OPENSTRATOS_GSM_GSMDEVICE_CLASS_
+using namespace std;
+
+class GSMDevice{
+	public:
+		GSMDevice();						//Instantiates a GSM device controlled using GPIO 4 (default, software pwr control) and /dev/ttyAMA0 for UART
+		GSMDevice(int gpio, string serial);			//Instantiates a GSM device controlled using a GPIO pin (given by GPIO parameter) and a UART port (given by serial);
+		void TogglePWR();					//Toggles the power status of the GSM module. Turns it on if it is off and turns it off if it is on.
+		bool Call(string number);				//Calls a given phone number. Returns true if suceeded, false if failed.
+		bool AbortCall();					//Aborts a phone call. Returns true if suceeded, false if failed or not in a call.
+		bool SendSMS(string message, string n);			//Sends a short message to a phone number. Returns true if suceeded, false if failed
+		void BroadcastGeolocation(string n);			//Tries to perform geolocation and sends coordinates to a phone number via SMS.
+		bool CheckGSMModule();					//Returns true if module is up and running, false if it is not
+	private:
+		uint16_t SerialReadLine();
+		uint16_t SerialSendRead(char *);
+		void FlushSerialInput();				//Discards all data received from the serial port.
+		bool SerialSendCompareResponse(char*, char*);		//Sends a string of data via serial port. Checks that the reply matches with another string.
+		bool InitGSMModule();					//Initializes the gsm module. Returns true if successful. False if failed.
+		bool InitSerial();					//Initializes the serial interface. Returns true if successful. False if failed.
+		int gpionum;						//GPIO pin used for software power control
+		string serialPort;					//Serial port identifier. Tipically /dev/ttyAMA0 in Raspbian. 
+		int fdesc;						//Standard unix file descriptor associated with the serial port (see serialPort)
+		char serialin[255];					//Buffer on which data received via the serial port is placed
+};
+#endif
+
+#ifndef OPENSTRATOS_GSM_DEFAULT_PARAMETERS_
+#define OPENSTRATOS_GSM_DEFAULT_PARAMETERS_
+#define DEFAULT_UART "/dev/ttyAMA0"
+#define DEFAULT_GPIO 4
+#define UART_BAUDRATE 4800
+#endif
+
+#ifndef OPENSTRATOS_GSM_GPIO_VALUES_
+#define OPENSTRATOS_GSM_GPIO_VALUES_
+#define HIGH 1
+#define LOW 0
+#endif