nrf52840 saadc ladder 160k resistors

[Oleg]

hi Engineers! I am trying to use int. pullup of 160k but no effect. the voltage remains zero on pin.

config.resistor_p = NRF_SAADC_RESISTOR_PULLUP;

what problem?

thx.

[Jørn]

Hello Oleg

I have used the SAADC example that comes with SDK 13. I have made sure that the saadc_init function is identical to yours, and everything on my end works as expected.

I have placed a 100kOhm resistor from pin P0.02 to ground, SAADC pullup enabled, gain 1/6, 10us acquisition time, 10 bit resolution, internal reference voltage (0.6V).

I get ADC values around 322 which is exactly where I expect it to be.

Are you using the example that follows with the SDK or your own code? If it is the latter, could you please try the example code and see if that gives a different result?

Best regards

Jørn Frøysa