Sending AT commands to SIM900 using Tiva tm4c1294xl launchpad.

Hello Sahan,

Without a code, to see how the data is being sent it is not possible to know why the issue is occurring.

Regards
Amit

SahanH said:

I used the UART_echo example provided by tiva ware board examples. Please suggest a method to send long strings.

The UARTSend function in the TivaWare uart_echo example uses ROM_UARTCharPutNonBlocking without checking the return status, such that the UARTSend function will silently discard characters once the UART TX FIFO is full (i.e. can cause problem with long strings).

How does your code send characters from the UART?

//Function for getting the respond from SIM900

/* ================================================== */
void SIMGet( char *Reply)

{ int i=0;

while(ROM_UARTCharsAvail(UART7_BASE))
{
Reply[i] = ROM_UARTCharGet(UART7_BASE);
i++;
}
// Reply[i] = '\0';
printf(Reply);
printf("\n");


}

/* ================================================== */


//Function for sending the AT Command. This function obtain the respond and resend in case of an error.

uint8_t ATCommand( char *_Command, char *ExpAnswer, char *ExpAnswer1, uint32_t _length )

{

uint32_t length=0;
char Command[30]; // In case of an ERROR message can send the command back.
memset(Command , '\0' , 30);
int i=0;
while(*_Command != '\t')
{
Command[i] = *_Command;
i++;
_Command++;
}
// Command[i] = '\0';
ReSend:
//Delayms(4000);

length = _length;
char Reply[30];
memset(Reply, '\0' , 30);
int k=0;


while((length--))
{
//
// Write the next character to the UART.
//
ROM_UARTCharPut(UART7_BASE, Command[k]);
k++;

}


Delayms(3000);


SIMGet(Reply);

// printf(Reply); // Printing to the console
// printf("\n");



// if(strncmp(Reply, ExpAnswer1 ,4) == 0)
// {
// goto ReSend;
// }

return 0;
}

// Main function

ATCommand("AT\r\n\t" , "OK\n\r" ,"ERROR\n\r" , 4); //For this command I get the reply as OK
Delayms(5000);

ATCommand("AT+CSTT=\"ebb\"\r\n\t" ,"OK\n\r", "ERROR\n\r" ,15 ); // This command not sending \n , so no reply
Delayms(5000);

ATCommand("AT+CIICR\n\r","OK\n\r\t", "ERROR\n\r" , 10);
Delayms(5000);


/* When I send this final command it sends me the SIM900 ERROR respond which I have no issue regarding that but the problem is only
"AT+CIICR ERRO" is displayed on the console.

Hi SahanH

I am working in the same project, this do you worked? You worked in Energia or in CCS?

Do you could show me the code please?

Regards
Matias

Hello SahanH, I tried to connect tivaC 123g lauchpad with module sim 900A, but it does not worked, could you give me the code.
Thank you so much.