ADS1259 SPI

Hi David,

There are some C Code examples for the MSP430F5508 using SPI communication here: http://www.ti.com/litv/zip/slac394c.

We don't have much example code specifically for the ADS1259. You can try seaching the E2E forums for some examples. These threads have some links to related code examples:

http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/t/217076.aspx
http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/p/197313/704459.aspx

Regards,
Chris

Hi,

I'm trying to get ads1259 to work but it won't work I don't know where is the problem.

What is the best method to check if the SPI is working?

My code :

#include <msp430.h>
#include "gpio.h"

int main(void)
{
volatile unsigned int i;
volatile unsigned char junk;

WDTCTL = WDTPW+WDTHOLD; // Stop WDT

GPIO_setOutputHighOnPin(
GPIO_PORT_P4,
GPIO_PIN3
); // CS chip select
P4DIR |= 0x08; // Set P4.3 to output direction
P4SEL |= BIT0+BIT4+BIT5; // P4.0,4,5 option select

UCA1CTL1 |= UCSWRST; // **Put state machine in reset**
UCA1CTL0 |= UCMST+UCSYNC+UCCKPL+UCMSB; // 3-pin, 8-bit SPI master
// Clock polarity high, MSB
UCA1CTL1 |= UCSSEL_2; // SMCLK
UCA1BR0 = 0x02; // /2
UCA1BR1 = 0; //
UCA1MCTL = 0; // No modulation
UCA1CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
UCA1IE |= UCRXIE; // Enable USCI_A0 RX interrupt

P4OUT &= ~0x08; // CS low
for(i=50000;i>0;i--);

//stop continnus mode

UCA1IFG &= ~UCRXIFG;
/* Send the byte */
UCA1TXBUF = 0x11;
/* Wait for the byte to be sent */
while ((UCA1IFG & UCRXIFG) == 0) { }

//read register - adress

UCA1IFG &= ~UCRXIFG;
/* Send the byte */
UCA1TXBUF = 0x21;
/* Wait for the byte to be sent */
while ((UCA1IFG & UCRXIFG) == 0) { }

//read register second optcode num of reg, and wait to recive data

UCA1IFG &= ~UCRXIFG;
/* Send the byte */
UCA1TXBUF = 0x00;
/* Wait for the byte to be received */
while ((UCA1IFG & UCRXIFG) == 0) { }
junk = UCA1RXBUF; // data reg config1 ads1259

#pragma vector=USCI_A1_VECTOR
__interrupt void USCI_A1_ISR(void)
{
switch(__even_in_range(UCA1IV,4))
{
case 0:break; // Vector 0 - no interrupt
case 2: // Vector 2 - RXIFG
//while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
//UCA0TXBUF = UCA0RXBUF;
break;
case 4:break; // Vector 4 - TXIFG
default: break;
}
}

Hi David,

What "symptoms" are you seeing, are you reading data back? Are you able to take any oscilloscope screenshots of the SPI communication?

One of my colleagues took a brief look at your code and noticed that the clock polarity is set HIGH, when it should be low:

David V said:

UCA1CTL0 |= UCMST+UCSYNC+UCCKPL+UCMSB; // 3-pin, 8-bit SPI master
// Clock polarity high, MSB

Regards,
Chris

Hi Christopher,

I changed it to low as you said.

1st problem was : I replaced by accident CS and CLK line on the chip :)

Now it the transmit data ok , I checked it with OSCOPE

code for transmit

transmitData = 0x20;
//USCI_A0 TX buffer ready?
while (!USCI_A_SPI_getInterruptStatus(USCI_A1_BASE,
USCI_A_SPI_TRANSMIT_INTERRUPT)) ;
USCI_A_SPI_transmitData(USCI_A1_BASE, transmitData);

But i'm trying to read the config0 and 1 register that means to read confing0 register I must send

first 0x20 and then 0x00 and then the rxbuf=b10xx0101.

But I always different  byte.

I don't know what is the problem.

Regards David.