UART communication between two msp430 controllers

Just from the hardware point of view you only need to connect
GND <-> GND
TxD <-> RxD
RxD <-> TxD
(if both MSPs have the same supply voltage)

Are you using custom boards?

I have done hardware connections as you mentioned.

I think there is software problem.

Regards,
Ankita kadam

But how shall we know? You did not post any code.

Dennis

Hi,

till now i checked, that my transmitter controller is transmitting data and data is there on Rx ;ine of receiving controller. But it is not generating interupt.

This is receiver controller code:

main code:
#include <msp430.h>
#include "Config.h"

int random;

int main(void)
{

Watchdog_Init(); //watchdog timer stopped
Clock_Init(); //Clock source selection
Port_IO(); //Port pins selected as input/output
Port_Sel(); //Port pins selected as alternate peripheral function
Port_Out(); //Port pin output is made high
UART_Init(); //UART is configured
__bis_SR_register(GIE); // Enter LPM0 w/ interrupt


while(1)
{
if(random=='A')
{
do_some_work();
}
}

return 0;
}

#pragma vector=USART0RX_VECTOR
__interrupt void usart0_rx (void)
{
IE1 = UTXIE0;
random= RXBUF0; //Motor_run to RXBUF0
TXBUF0 = random; //TXBUF0 to Motor_run;
}


#pragma vector=USART0TX_VECTOR
__interrupt void usart0_tx (void)
{
IE1 = URXIE0;
}

config.c
#include <msp430.h>
#include "Config.h"

void Watchdog_Init(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
}

void Clock_Init(void)
{
DCOCTL= DCO0; // selecting minimum DCO frequency--100kHz
BCSCTL1= XT2OFF | XTS | DIVA_0; //external oscillator in HF mode
BCSCTL2= SELM_3 | DIVS_0; //SM clock is given from external oscillator 1 and is divided by 8(SMCLK=1MHz)
}
void Port_IO(void)
{
P3DIR |= BIT4 ; // P3.4,5 = USART0 TXD/RXD
P4DIR |= BIT2 | BIT3 | BIT4 | BIT5 | BIT6 | BIT7; //making these port pins output
P6DIR |= BIT6 | BIT7 | BIT5; //making these port pins output
P5DIR |= BIT1 | BIT2 | BIT3 | BIT4;

}
void Port_Sel(void)
{
P3SEL |= BIT4 | BIT5; // P3.4,5 = USART0 TXD/RXD
P4SEL |= BIT4 | BIT3 | BIT2 | BIT5; //making these port pins as alternate function
P6SEL |= BIT6 | BIT7;
}
void Port_Out(void)
{
P4OUT = BIT6 | BIT7;
}
void UART_Init(void)
{
UCTL0 |= SWRST; // Initialize USART state machine
UCTL0 = 0x11; // 8-bit character
UTCTL0 |= SSEL1; // UCLK= SMCLK
UBR00 = 0x41; // 8MHz 9600 modulation
UBR10 = 0x03; // 8MHz 9600 modulation
UMCTL0 = 0x04; // 8MHz 9600 modulation
ME1 |= UTXE0 + URXE0; // Enable USART0 TXD/RXD
UCTL0 &= ~SWRST; // Initialize USART state machine
IE1 |= URXIE0; // Enable USART0 RX interrupt
}

void delay(void)
{
volatile unsigned long int i;
i = 10000; // SW Delay
do (i--);
while(i != 0);
}

Hi folks,

Sorry to dig this thread up. I am having the same problem getting two MSP430 devices to communicate with each other via UART. Each MSP430 can communicate with a FT231x chip but not with each other.

Mr. Kadam: Did you ever get around this problem or find a solution?

Thanks.

Hi,

Problem was solved, but it was long time back and I am sorry that I do not remember.

I will check the code and If I remember something, I will let you know.

Regards,

Ankita Kadam

Thanks for the update. In my case, the problem is presumably clock source. I soldered another batch of boards, loaded the same code, and things started to work.

If you find anything, please do post back.

Cheers,

Zhiyong