DA14531 Temperature sensor driver in SDK

ID: LPCBARESDK-672

Status: Fixed

First reported: 6.0.14.1114

Fixed in: 6.0.20.1338

Description

According to the DA14531 datasheet, the SW must restore the registers GP_ADC_OFFP_REG and GP_ADC_OFFN_REG to the default settings: 0x200. This is the value corresponding to the reference temperature.

In the SDK6, while reading the temperature, and if the sw is using the adc_offset_calibrate() in order to calibrate the ADC, the registers GP_ADC_OFFP_REG and GP_ADC_OFFN_REG will have different values.

The mechanism to get correct temperature readings is following:

  • Store the calibration values from the registers into RAM

  • Set the default values (0x200) to these two registers

  • Perform a temperature measurement

  • Restore the calibration values from RAM into the registers

Workaround

As a workaround, the application should take care of storing the ADC registers configuration in local variables before calling the adc_offset_calibrate() function and restore the original value once the ADC measurement is done.