nrf52832 temperature sensor piece wise linear function registers

[Thiemo van Engelen]

Hi,

Can somebody explain how the Ax, Bx and Tx registers are used in the calculation of the temperature reported by the temperature sensor block in an nRF52832?

What we sometimes see is that at certain temperatures, the temperature sensor seems to "jump" between values, with a difference that is more than the T_TEMP,STB of +- 0.25 degC. Is it possible that the pieces of the piecewise correction are not continuous and thus make a jump at certain temperature/ADC values?

Regards,

Thiemo van Engelen

[Susheel Nuguru]

Hi Tiemo,

The temperature sensor is on the die of the chip, so more accurately it measures the temperature of the chip, rather than the temperature of the environment.  If you are seeing that this jump is sudden and not reflecting the environment around it, then this could be because the chip's temperature does not follow the temperature around it. If you want very accurate temperature measurement outside the chip to reflect the environment, then you should use an external temperature sensor. Lot of customers use the temperature sensor inside the nordic chip to get an approximate temperature and act accordingly.