再次求助，ADS1118读取第二通道的问题

再次求助，ads1118要读取第二通道，按如下设置，读到的都是第一通道的值，无法读取第二通道的值，请高人再次指点。感谢！

#include "msp430x54xA.h"

void GPIO_Init(void);
void SPI_Init(void);
void ADS_Config(void);
int ADS_Read(void);
signed int WriteSPI(unsigned int Config, unsigned char mode);

float Voltage23;

void main(void)
{

volatile int ADC_Result;

WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer

GPIO_Init();
SPI_Init();
ADS_Config();
while(1)
{
ADS_Config();
ADC_Result = ADS_Read(); // Read data from ADS1118

Voltage23 = ADC_Result*1.0/32768*2.048;
__delay_cycles(100);

_no_operation();
}
}

void GPIO_Init(void)
{
P1OUT |= 0x02; // Set P1.1 for CS
P1DIR |= 0x02; // Set P1.1 to output direction
P3SEL |= 0x80; // P3.7 option select
P5SEL |= 0x30; // P5.4,5 option select
P5DIR |= BIT0; // P5.0 Output
P5OUT |= BIT0; // P5.0 Output High
}

void SPI_Init(void)
{
UCB1CTL1 |= UCSWRST; // **Put state machine in reset**
UCB1CTL0 |= UCMST+UCSYNC+UCCKPH+UCMSB; // 3-pin, 8-bit SPI master
// Clock polarity high, MSB
UCB1CTL1 |= UCSSEL_2; // SMCLK
UCB1BR0 = 200; // /2
UCB1BR1 = 1; //
UCB1CTL1 &= ~UCSWRST; // **Initialize USCI state machine**

__delay_cycles(100); // Wait for slave to initialize
}

void ADS_Config(void)
{
signed int Config_Value; // Initial Config Register
Config_Value = 0xB48C;
// ADS1118 configuration AIN0/AIN1, FS=+/-2.048, DR=128sps, PULLUP on DOUT

P1OUT &=~ 0x02; // Set CS low
WriteSPI(Config_Value,0); // Write configuration to ADS1118
P1OUT |= 0x02; // Set CS high
}

int ADS_Read(void)
{
unsigned int Data, Config_Value;

Config_Value = 0xB48C;
// ADS1118 configuration AIN0/AIN1, FS=+/-2.048, DR=128sps, PULLUP on DOUT

P1OUT &=~ 0x02; // Set CS low
Data = WriteSPI(Config_Value,1); // Read data from ADS1118
P1OUT |= 0x02; // Set CS high

return Data;
}

/*
* Mode 0: Only write config register to ADS1118
* Mode 1: Write config register to ADS1118 as well as read data from ADS1118
*/
signed int WriteSPI(unsigned int config, unsigned char mode)
{
signed int msb;
unsigned int temp;
volatile signed int dummy;

temp = config;
if (mode==1) temp = 0;

while(!(UCB1IFG&UCTXIFG));
UCB1TXBUF = (temp >> 8 ); // Write MSB of Config
while(!(UCB1IFG&UCRXIFG));
msb = UCB1RXBUF; // Read MSB of Data

while(!(UCB1IFG&UCTXIFG));
UCB1TXBUF = (temp & 0xff); // Write LSB of Config
while(!(UCB1IFG&UCRXIFG));
msb = (msb << 8) | UCB1RXBUF; // Read LSB of Data

while(!(UCB1IFG&UCTXIFG));
UCB1TXBUF = (temp >> 8 ); // Write MSB of Config
while(!(UCB1IFG&UCRXIFG));
dummy = UCB1RXBUF; // Read MSB of Config

while(!(UCB1IFG&UCTXIFG));
UCB1TXBUF= (temp & 0xff); // Write LSB of Config
while(!(UCB1IFG&UCRXIFG));
dummy = (dummy <<8) | UCB1RXBUF; // Read LSB of Config

__delay_cycles(100);

return msb;
}

是这样的，对ADS1118，当次写入命令时，读到的值是上一次配置的转化结果。当你对ADC进行这次配置时，在下一次不管配置如何，读到的都是按这次配置的转化结果。

  首先感谢专家。我当时也这么考虑过，但是试了好久，也用好几种控制字。还用了您帖子上的程序，好像都是只读到一个通道。