ADS1256的状态寄存器读取问题

初始化ADS1256之后，

void ADS1256_Init(void)
{
/*Init data ready line */
ADS1256_Config_GPIO();

/*Init SPI2 for ADS1256 interface */
SPIx_Initialize(SPI2);

ADS1256_SetCommand(CMD_RESET);
ADS1256_DelayNumUs(100000); //wait for Vref is stable

/*it is strongly recommended to perform an additional self-calibration by issuing
the SELFCAL command after the power supplies and voltage reference have had time
to settle to their final values in pdf.27*/
while(ReadDrdyLine());
ADS1256_SetCommand(CMD_SELFCAL);

while(ReadDrdyLine());
/*Most Significant Bit First,Auto-Calibration Enabled,Buffer Enabled:11110111b */
ADS1256_WriteReg(REG_STATUS ,0xF7);

while(ReadDrdyLine());
/*PGA=1 */
ADS1256_WriteReg(REG_ADCON,0x00);

while(ReadDrdyLine());
/*select channle AIN2 as initial analog input*/
ADS1256_SetSingleChannel(2);

while(ReadDrdyLine());
/*set data rate as 10sps as initial rate*/
ADS1256_WriteReg(REG_DRATE,RATE_5SPS);

/*After changing the PGA, data rate, buffer status, writing to the OFC or FSC registers,
and enabling or disabling the sensor detect circuitry,perform a synchronization operation
to force DRDY high. It will stay high until valid data is ready*/
while(ReadDrdyLine());
ADS1256_SetCommand(CMD_SYNC);//synchronization command
ADS1256_SetCommand(CMD_WAKEUP);//wakeup command


while(ReadDrdyLine());
ADS1256_SetCommand(CMD_SELFCAL);
ADS1256_DelayNumUs(10);//it is important for this delay
/*When the voltage on VREFP or VREFN exceeds the buffer analog input range
(AVDD – 2.0V), the buffer must be turned off during self gain calibration.*/

}

配置ADS1256的STATUS状态寄存器的值为0xF7,然后去读这个状态寄存器的值，结果为0x30,这是为什么呢？（读其他的寄存器的值，却和配置的一样。）

求各位TI的老师指点一下。。。

状态寄存器是只读的, 0x30 的意义详细见数据手册的说明吧, P30

ADS1256的datasheet中并没有说明STATUS是只读的，只是说明STATUS寄存器的前四个bit位是只读的，后面的bit[1:3]是可以写的，肯定是可写的。不然无法正确配置ADS1256。

问题原因找到了：在datasheet中有这样一段话：/*it is strongly recommended to perform an additional self-calibration by issuing the SELFCAL command after the power supplies and voltage reference have had time to settle to their final values in pdf.27*/  所以在初始化ADS125之前，应该发一个自校准命令。但是需要注意的是发送自校准命令应该这样处理：

while(ReadDrdyLine());
ADS1256_SetCommand(CMD_SELFCAL);
while(!ReadDrdyLine());
while(ReadDrdyLine());

在完成ADS1256之后，也应该发一个自校准命令，以上述代码格式，然后继续去回读已配置的寄存器，就能读到正确的值。

我现在可以读取寄存器的数据，但是读取不了电压的数据，这种情况你有没有试过啊？

求ads1255驱动，我也在用ads1255，DRDY输出不对，怎么办？求大神指教！

你好，可以留下QQ么，咱们可以交流下。