static bool wait_gsm_status(int s)
{
int status;
int attempt;
attempt = 0;
while (attempt < 10) {
status = gsm_status(f_gsm);
if (status == s)
return true;
switch (status) {
case 0:
printf("%s: gsm not registered, idle\n", __func__);
break;
case 1:
printf("%s: gsm registered\n", __func__);
break;
case 2:
printf("%s: not registered, searching\n", __func__);
break;
case 3:
printf("%s: not registered, denied\n", __func__);
break;
case 4:
printf("%s: not registered, unknown\n", __func__);
break;
case 5:
printf("%s: not registered, roaming\n", __func__);
break;
}
usleep(1000000);
attempt++;
}
return false;
}
static int8_t gsmAutobaud(void)
{
char buff[8];
int8_t try;
int8_t resp;
// A HEX string such as “00 49 49 49 49 FF FF FF FF” will be sent out
// through serial port at the baud rate of 115200 immediately after
// SIM900 is powered on.
// Send AT command for autobaud
gsmDebug("Autobauding...\n");
for(try=3; try; try--) {
_gsmWriteLine("AT");
_gsmRead(buff, 8);
if (buff[0] == '0') {
gsmDebug("DONE\n");
// The GSM has been already configured:
// return error to avoid re-configuration
return ERROR;
}
resp = _gsmReadResult();
if (resp == OK) {
gsmDebug("DONE\n");
return resp;
}
gsmDebug("FAILED\n");
}
return ERROR;
}
#else
# define gsmAutobaud() OK
#endif
static int8_t gsmConfigure(void)
{
char buff[8];
int8_t resp;
// Load configuration
_gsmWriteLine("ATE0");
_gsmRead(buff, 8);
resp = _gsmReadResult();
if (resp != OK) {
return resp;
}
// Configure TA Response Format
_gsmWriteLine("ATV0");
resp = _gsmReadResult();
if (resp != OK) {
return resp;
}
return OK;
}
int8_t gsmPowerOn(void)
{
int8_t result;
// TODO: check if the modem is already on
// either using the STATUS line or by sending an AT command
if (gsm_status()) {
#if 0
// Modem already ON... checking AT command
_gsmWriteLine("AT");
result = _gsmReadResult();
if (result == OK)
return result;
// Not responding to AT comand... shut-down
gsm_powerOff();
DELAY(10000);
#endif
// Resetting the modem
LOG_INFO("GSM: Resetting...\n");
gsm_reset();
} else {
LOG_INFO("GSM: Powering-on...\n");
gsm_on();
}
// When DCE powers on with the autobauding enabled, it is recommended
// to wait 2 to 3 seconds before sending the first AT character.
LOG_INFO("Wait (20s) for network attachment\n");
DELAY(20000);
result = gsmAutobaud();
if (result != OK)
return result;
result = gsmConfigure();
return result;
}
void gsmPowerOff(void)
{
LOG_INFO("GSM: Powering-off...\n");
gsm_off();
LED_GSM_OFF();
}
