gsm.c File Reference

Talk to the GSM modem. More...

#include "gsm.h"
#include "log.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

Functions
int	get_line (SerialPort *sp, char *const buffer, int buflen)
	Read a CR LF terminated line from the serial port.
int	GSMSendCommand (SerialPort *sp, const char *const msg)
	Send a command to the GSM modem, and listen for the echoed response.
int	GSMSendMessage (SerialPort *sp, const char *const number, const char *const msg)
int	GSMCheckSignal (SerialPort *sp)
	Check the network association and signal strength of the GSM modem.
int	GSMSetSMSMode (SerialPort *sp)
int	GSMSendFile (SerialPort *sp, const char *const number, const char *const filename)
Variables
const char *const	CREG_MESSAGE = "AT+CREG?\r\n"
	Message to read Network Registration Status.
const char *const	CREG_MESSAGE_RES = "+CREG: "
const int	CREG_MESSAGE_RES_LEN = 10
const char *const	CSQ_MESSAGE = "AT+CSQ\r\n"
	Message to read signal strength.
const char *const	CSQ_MESSAGE_RES = "+CSQ: "
const int	CSQ_MESSAGE_RES_LEN = 9
const char *const	CMGF_MESSAGE = "AT+CMGF=1\r\n"
	Message to put modem into SMS mode.

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Detailed Description

Talk to the GSM modem.

Copyright (C) 2004 Alistair Riddoch, The University of Southampton

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Function Documentation

int get_line (  SerialPort *  sp, char *const  buffer, int  buflen )  [static]

Read a CR LF terminated line from the serial port. The CR LF characters are stripped, and the buffer is NULL terminated so the result can be used as a string. Parameters: sp  serial port to read from buffer  buffer to store the line in buflen  size of buffer to read data into Returns: the number of bytes read, or minus one if an error or timeout occured.

int GSMCheckSignal (  SerialPort *  sp  )

Check the network association and signal strength of the GSM modem. Parameters: sp  pointer to serial port to be used to talk to the modem. Returns: zero if the modem is associated with a GSM network, and has good enough signal strength to send messages, or 1 if GSM network is not available, 2 if GSM signal strength is too weak, or -1 if an error occured talking to the modem.

int GSMSendCommand (  SerialPort *  sp, const char *const  msg )

Send a command to the GSM modem, and listen for the echoed response. Returns: zero if the message was echoed back correctly, and one otherwise.

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