SAR_ADC Function Documentation

 

Sys_Calibrate_SARADC

void Sys_Calibrate_SARADC(uint32_t vddsar_mv, uint32_t supply_src, uint32_t * offset, float * gain)

 

Calibrate the SAR ADC, generating gain and offset values.

 

The gain and offset values are stored in the SAR ADC but are returned here as well.

 

Location: sar_adc.h:72

 

Parameters

Direction Name Description

in

vddsar_mv

Set the SAR supply voltage. 2.5 to 3.3 V sets SENSOR_CLK between 8 and 16 MHz. Less than 2.5 V sets SENSOR_CLK to 2 MHz.

in

supply_src

Select the SAR supply source: use SAR_SUPPLY_BY_VBAT, SAR_SUPPLY_BY_GPIO9

out

offset

Gets the offset stored in SAR_ADC

out

gain

Gets the calibrated gain correction

 

Assumptions

The SAR ADC is configured to use VBAT for the calibration.

 

Example Code for Sys_Calibrate_SARADC

    // Calibrate the SAR ADC with SAR positive input having signal between VSSA 

    // and 3000mV. 

    // Set gain_correction to the calibrated gain correction 

    // Set sar_adc_offset to the offset stored in SAR-ADC (i.e. 8192 levels)

    float gain_correction = 0;

    uint32_t sar_adc_offset = 0;

    Sys_Calibrate_SARADC(SAR_ADC_VBAT_SUPPLY_MV, SAR_SUPPLY_BY_VBAT, &sar_adc_offset, &gain_correction);