CCS/MSP430FR4133: Trying to transmit data via SIM800 GSM module

Hi Kamalesh,

I would recommend that you approach this in a different way:
* Without the GSM module, confirm that your MCU / RxTx is working correctly by testing your circuit / code with an echo setup (Tx connected to Rx).
* Without the MCU circuitry, connect the GSM module to a serial terminal using an adapter (USB-RS232, etc..) and issue the AT commands through the terminal to confirm the module is performing as expected.

Hi Kamalesh,

You shouldn't use "while(!(UCA0IFG&UCRXIFG));" in a interrupt ISR.  You can use a array to store the receive data and check if it's correct. There is a USB to Serial tool in MSP430FR4133 LaunchPad. You can use it and serial terminal in PC to confirm both LaunchPad and the GSM module are performing as expected. Make sure the values of receiving and sending are correct.

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Winter,

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hi Winter Yu,

I have tried with the same code , Now I am receiving a SMS in my Mobile but i am just receiving a blank message....
and thank you for replying.....

#include <msp430.h>
#include <String.h>
#include <stdint.h>
#include <stdlib.h>

void Init_GPIO();
void Uart_TXn();
//const char TXData = 'AT';

unsigned char ctrlz = (char)26;
unsigned char at[4] = {"AT\r\n"};
unsigned char cmgf[13] = {"AT+CMGF=1\r"};
unsigned char cmgs[30] = {"AT+CMGS=\"+918015989208\"\r"};
char* msg = "hello";
unsigned char RXData;
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer

int index = 0, i = 0;
long int k = 0;
int ind = 0;

unsigned char tmpLatLong[10] = {0};
unsigned char txfrBuffer[1]='a';
// Configure GPIO
Init_GPIO();
PM5CTL0 &= ~LOCKLPM5; // Disable the GPIO power-on default high-impedance mode
// to activate 1previously configured port settings

__bis_SR_register(SCG0); // disable FLL
CSCTL3 |= SELREF__REFOCLK; // Set REFO as FLL reference source
CSCTL0 = 0; // clear DCO and MOD registers
CSCTL1 &= ~(DCORSEL_7); // Clear DCO frequency select bits first
CSCTL1 |= DCORSEL_3; // Set DCO = 8MHz
CSCTL2 = FLLD_0 + 243; // DCODIV = 8MHz
__delay_cycles(3);
__bic_SR_register(SCG0); // enable FLL
while(CSCTL7 & (FLLUNLOCK0 | FLLUNLOCK1)); // Poll until FLL is locked

CSCTL4 = SELMS__DCOCLKDIV | SELA__REFOCLK; // set default REFO(~32768Hz) as ACLK source, ACLK = 32768Hz
// default DCODIV as MCLK and SMCLK source

// Configure UART pins
P1SEL0 |= BIT0 | BIT1; // set 2-UART pin as second function

// Configure UART
UCA0CTLW0 |= UCSWRST;
UCA0CTLW0 |= UCSSEL__SMCLK;

// Baud Rate calculation
// 8000000/(16*9600) = 52.083
// Fractional portion = 0.083
// User's Guide Table 14-4: UCBRSx = 0x49
// UCBRFx = int ( (52.083-52)*16) = 1
UCA0BR0 = 52; // 8000000/16/9600
UCA0BR1 = 0x00;
UCA0MCTLW = 0x4900 | UCOS16 | UCBRF_1;

UCA0CTLW0 &= ~UCSWRST; // Initialize eUSCI
UCA0IE = UCTXIE | UCRXIE; // Enable USCI_A0 RX interrupt

while(!(UCA0IFG&UCTXIFG));

Uart_TXn(&at[0],4);
k = 200000;
do{
--k;
} while(k > 0);
Uart_TXn(&cmgf[0],sizeof(cmgf));
k = 200000;
do{
--k;
} while(k > 0);

Uart_TXn(&cmgs[0],sizeof(cmgs));
k = 200000;
do{
--k;
} while(k > 0);

Uart_TXn(&txfrBuffer[0], sizeof(txfrBuffer));
k = 2000000;
do{
--k;
} while(k > 0);

Uart_TXn("\r", sizeof("\r"));
k = 2000000;
do{
--k;
} while(k > 0);

Uart_TXn(&ctrlz, sizeof(ctrlz));
k = 200000;
do{
--k;
} while(k > 0);
while(1);

//__bis_SR_register(LPM3_bits|GIE); // Enter LPM3, interrupts enabled
// __no_operation(); // For debugger
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_A0_VECTOR
__interrupt void USCI_A0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_A0_VECTOR))) USCI_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch(__even_in_range(UCA0IV,USCI_UART_UCTXCPTIFG))
{
case USCI_NONE: break;
case USCI_UART_UCRXIFG:
while(!(UCA0IFG&UCRXIFG));
RXData = UCA0RXBUF;
__no_operation();
break;
case USCI_UART_UCTXIFG: break;
case USCI_UART_UCSTTIFG: break;
case USCI_UART_UCTXCPTIFG: break;
default: break;
}
}

void Init_GPIO()
{
P1DIR = 0xFF; P2DIR = 0xFF; P3DIR = 0xFF; P4DIR = 0xFF;
P5DIR = 0xFF; P6DIR = 0xFF; P7DIR = 0xFF; P8DIR = 0xFF;
P1REN = 0xFF; P2REN = 0xFF; P3REN = 0xFF; P4REN = 0xFF;
P5REN = 0xFF; P6REN = 0xFF; P7REN = 0xFF; P8REN = 0xFF;
P1OUT = 0x00; P2OUT = 0x00; P3OUT = 0x00; P4OUT = 0x00;
P5OUT = 0x00; P6OUT = 0x00; P7OUT = 0x00; P8OUT = 0x00;
}

void Uart_TXn( unsigned char *str, int size)
{
int i = 0;
while(size > 0)
{
UCA0TXBUF = str[i++];
while(!(UCA0IFG & UCTXIFG));
size--;
}
}