nrf52832 adc wrong value

RE: nrf52832 adc wrong value

Berker — Tue, 20 Nov 2018 06:44:45 GMT

Hi,

You can use internal reference and gain(1/6) to measure between 0 to 3.6V.

For example

ADC range = 0.6V/(1/6) = 3.6V

ADC range = 0.6V/(1/2) = 1.2V, you change it as desired

You may not use external regulator or reference,there is internal one. It is possible to adjust gain 1/2,1/3,1/4,1/5,1/6,1,2,4 using CONFIG register directly or SDK convenient function.

RE: nrf52832 adc wrong value

Sunil vignesh — Tue, 20 Nov 2018 06:19:57 GMT

Hi Berger,

I will check the link sir. but by using this. How to set the voltage reference sir. we need to put one voltage regulator to give voltage reference value as constant one right?. or we can use SAADC to measure (0-VDD), without any voltage divider..!.

RE: nrf52832 adc wrong value

Berker — Mon, 19 Nov 2018 18:25:53 GMT

Thanks, it works as expected now.

RE: nrf52832 adc wrong value

Berker — Mon, 19 Nov 2018 12:50:29 GMT

Hi Sunil,

Look at this link:

https://devzone.nordicsemi.com/b/blog/posts/measuring-lithium-battery-voltage-with-nrf52

You can do simple voltage divider and add one capacitor. I think, reading battery can done with voltage similar above example.

RE: nrf52832 adc wrong value

Jørgen Holmefjord — Mon, 19 Nov 2018 12:07:17 GMT

Hi,

It seems that you have mistaken the SAADC channels for analog inputs. Any analog input can be assigned to any channels, i.e. channel 4 is not hardwired to AIN4 (P0.28). What you are actually reading is the VDD voltage that you have assigned as the positive input for channel 4 on line 17: SAADC_CH_PSELP_PSELP_VDD.

If you want to measure AIN4 (P0.28), you need to change this to SAADC_CH_PSELP_PSELP_AnalogInput4.

Best regards,
Jørgen

RE: nrf52832 adc wrong value

Sunil vignesh — Mon, 19 Nov 2018 11:58:54 GMT

Hi Berker,

I also need to read the battery value. but with out adc is it possible to read the battery level with internal registers. If adc is used means can you give any schematic related to ADC connection. It will be helpful for my project.