CCS/MSP430I2041: sd24 accuracy is incorrect

Hi Susan,

Could you please elaborate upon your post to explain in detail what your customer's question is? 

Best regards,

Matt

What reference voltage source are they using?

Thanks for your reply.

void impr_SD24_init(void)
{
SD24_init(SD24_BASE, SD24_REF_INTERNAL); 

//Group with Channel 0
SD24_initConverterAdvancedParam param = { 0 }; 
// Enable interrupt
param.converter = SD24_CONVERTER_2; 
//param.conversionMode = SD24_CONTINUOUS_MODE; 
param.conversionMode = SD24_SINGLE_MODE;
/*
#define SD24_DATA_FORMAT_BINARY (0x00)
#define SD24_DATA_FORMAT_2COMPLEMENT (SD24DF)
*/
param.groupEnable = SD24_NOT_GROUPED;
/*
#define SD24_NOT_GROUPED (0x00)
#define SD24_GROUPED (SD24GRP) 
*/
param.inputChannel = SD24_INPUT_CH_TEMPERATURE;
//param.inputChannel = SD24_INPUT_CH_ANALOG; 
/*
#define SD24_INPUT_CH_ANALOG (SD24INCH_0)
#define SD24_INPUT_CH_TEMPERATURE (SD24INCH_6) 
*/
param.dataFormat = SD24_DATA_FORMAT_2COMPLEMENT;
/*
#define SD24_DATA_FORMAT_BINARY (0x00)
#define SD24_DATA_FORMAT_2COMPLEMENT (SD24DF) 
*/
param.interruptDelay = SD24_FOURTH_SAMPLE_INTERRUPT; 
param.oversampleRatio = SD24_OVERSAMPLE_256; 
param.gain = SD24_GAIN_1; 
SD24_initConverterAdvanced(SD24_BASE, &param);

param.converter = SD24_CONVERTER_0;
param.conversionMode = SD24_SINGLE_MODE;
param.groupEnable = SD24_NOT_GROUPED;
param.inputChannel = SD24_INPUT_CH_ANALOG;
param.dataFormat = SD24_DATA_FORMAT_2COMPLEMENT;
param.interruptDelay = SD24_FOURTH_SAMPLE_INTERRUPT;
param.oversampleRatio = SD24_OVERSAMPLE_256;
param.gain = SD24_GAIN_1;
SD24_initConverterAdvanced(SD24_BASE, &param);

param.converter = SD24_CONVERTER_1;
param.conversionMode = SD24_SINGLE_MODE;
param.groupEnable = SD24_NOT_GROUPED;
param.inputChannel = SD24_INPUT_CH_ANALOG;

param.dataFormat = SD24_DATA_FORMAT_2COMPLEMENT;
param.interruptDelay = SD24_FOURTH_SAMPLE_INTERRUPT;
param.oversampleRatio = SD24_OVERSAMPLE_256;
param.gain = SD24_GAIN_1;
SD24_initConverterAdvanced(SD24_BASE, &param);


SD24_enableInterrupt(SD24_BASE, SD24_CONVERTER_2, SD24_CONVERTER_INTERRUPT);
///__delay_cycles(10);
}

Susan,

Thank you for providing the SD24 initialization code but could you please provide further detail regarding both mine and Keith's questions above?

Best regards,

Matt

He use internal reference.

Susan,

Yes thank you for that clarification but I am still hoping that you can more clearly state your customer's problem. I am still confused with the following lines from your initial post:

According to the documentation, it should be

7fffff/928mv=9039 1mv=9039

What do you mean by "it should be"? What documentation?

The sample reception is 32-bit SD24_getResults, and the SD24_getHighWordResults is not used to receive 24 bits.

But the maximum he has tested in 1mv now is 7300.

What is the test you are referring to? What is the significance of the 1mV and the value of 7300?

-Matt