Help uart programming msp430fr5969

Titouni,

are you sure, your UCA1MCTLW setting is correct? From the user's guide it is 0x9200 when using 32k768 for 9600 baud:

By the way: As you can see this clock source is a bad idea for 9600 baud since it's error is extremely large.

Dennis

The 32768 Hz ACLK is not suitable as BRCLK for 9600 b/s. This frequency is to low and not an integer multiple of 9600. When used this way, the result is marginal at best.

The DOC frequency of MSP430FR5xxx is factory trimmed and accurate enough to be used as BRCLK. You should use that instead.

thank you for your answer,

what type of clock that does not pose a problem?

thank you for your answer,

can you give me an example where I can find how to program the DOC frequency

Titouni,

I just saw that you your code is based on the code examples provided by TI, right? Looks like this one:

• msp430fr59xx_euscia0_uart_02.c                    eUSCI_A0 UART echo at 9600 baud using BRCLK = 32768Hz

I am wondering why there is such an example given which has that bad performance?! Did you try the example without modifications? Just the loopback?

Anyway - you could change your code based on:

• msp430fr59xx_euscia0_uart_01.c                    eUSCI_A0 UART echo at 9600 baud using BRCLK = 8MHz

which uses 8MHz as clock source which has the following errors (much smaller):

Dennis

yes, I just used the example ( msp430fr59xx_euscia0_uart_02.c ) . i changed th clk to 8 mhz as mentioned in (msp430fr59xx_euscia0_uart_01.c ) and now i have UCOE=1 (USCI Overrun Error Flag) and UCRXERR=1 (USCI RX Error Flag).

Did you first check only the example code as it is to see if it works in general?

Dennis

yes and it works in general.

when i use UART0 to transmit the data sequence 0x01 0x03 0x0c 0x00 and I use a terminal I get Read data : 01 03 0C 00 .

now when i use uart1 to connect the msp430 with bluetooth (pan1026) and i transmit the sequence i get nothing in read data.

and i have the probleme of UCOE=1 (USCI Overrun Error Flag) and UCRXERR=1 (USCI RX Error Flag).

Did you double check if you changed everything from UART0 to UART1? Including the different pins, etc.?
I would recommend to make the computer <-> MSP test with the other UART first, without the BT module.

Dennis

i have changed evrey thing from uart0 to uart1.

ok i will make the computer <-> MSP test with uart1 . For this I use an oscilloscope to view the output?

i see what there is in tx and i found the same message that i want to send. but there is nothing in rx.

Can you please post your code again (the new one)?

Dennis

here is my code

#include "driverlib.h"

unsigned char TCU_HCI_RESET_REQ[4] = {0x01, 0x03, 0x0c, 0x0b};
unsigned char i;
int main(void)
{

	WDTCTL = WDTPW | WDTHOLD;                 // Stop Watchdog

  P2SEL1 |= BIT5| BIT6;                    // Configure UART pins
  P2SEL0 &= ~(BIT5 | BIT6);
  //PJSEL0 |= BIT4 | BIT5;                    // Configure XT1 pins

  // Disable the GPIO power-on default high-impedance mode to activate
  // previously configured port settings
  PM5CTL0 &= ~LOCKLPM5;
  // Startup clock system with max DCO setting ~8MHz
  CSCTL0_H = CSKEY >> 8;                    // Unlock clock registers
  CSCTL1 = DCOFSEL_3 | DCORSEL;             // Set DCO to 8MHz
  CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;
  CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;     // Set all dividers
  CSCTL0_H = 0;                             // Lock CS registers

  // Configure USCI_A0 for UART mode
  UCA1CTLW0 = UCSWRST;                      // Put eUSCI in reset
  UCA1CTLW0 |= UCSSEL__SMCLK;               // CLK = SMCLK
  // Baud Rate calculation
  // 8000000/(16*9600) = 52.083
  // Fractional portion = 0.083
  // User's Guide Table 21-4: UCBRSx = 0x04
  // UCBRFx = int ( (52.083-52)*16) = 1
  UCA1BR0 = 52;                             // 8000000/16/9600
  UCA1BR1 = 0x00;
  UCA1MCTLW |= UCOS16 | UCBRF_1;
  UCA1CTLW0 &= ~UCSWRST;                    // Initialize eUSCI
  UCA1IE |= UCRXIE;                         // Enable USCI_A0 RX interrupt



  USART1_SendData(TCU_HCI_RESET_REQ,4);
  

}
void USART1_SendByte (unsigned char data) {
	while(!(UCA1IFG & UCTXIFG));

	UCA1TXBUF = data;
}
void USART1_SendData (unsigned char data[], unsigned char length) {
	unsigned char i;

	for(i=0; i<length; i++) {
		USART1_SendByte(data[i]);
		
	}
}

Titouni,

you should insert something into your program that keeps it alive. Like a

while( 1 );

at the end of your main(). Or enter the low-power-mode. You just erased those lines from the example code.

And why do you enable the RX interrupt? There is no ISR. It won't be a problem because you do not enable the global interrupts, but it is useless anyway.

Dennis

when i add

  // Enable global interrupts
     __enable_interrupt();

in the end of main(); it ends execution. 

i have no idea how to use ISR it's my first time i use a microcontroller.

No, you should not enable interrupts without having an ISR for it. Your program might crash. I mean the "while( 1 );" at the end of your main().

there is the result when i use uart0  i get the same message

and when i use uart0 i get nothing 

in the datasheet of the bluetooth it mentioned that if i transmit the data sequence 0x01 0x03 0x0c 0x00. the microcontroller receives the data sequence 0x04 0x0e 0x04 0x04 0x03 0x0c 0x00  

and this is the connection between the msp430 and the bluetooth

Is there other circuitry connected to the bluetooth IC on the green board? Something from the USB connector? Maybe something pulls the signal down?

i removed the connection resistance between the port USB and SFTDI and I took directly RX , TX.

I checked the power and i found 3.3v.