RE: Jittery results from SAADC on nRF52832

adamsperry — Tue, 23 Apr 2019 15:11:08 GMT

I just determined my problem yesterday. It was not with the SAADC. It was an issue of type casting when recombining the high and low bytes on my host computer. Thank you for your response.

RE: Jittery results from SAADC on nRF52832

Edvin — Tue, 23 Apr 2019 14:33:51 GMT

Hello,

[quote user=""]Pot -> SAADC on nRF52 DK -> NUS on nRF52 DK -> NUS on Sparkfun -> UART on sparkfun -> host computer[/quote]

There are a few step in this series of peripherals. Can you please try to print the SAADC values on the nRF52 DK on the UART or something? Just to see if the small negative number is present already here?

I just want to figure out where the small negative number is introduced. The pot, the SAADC, the NUS, the sparkfun, the UART on the sparkfun. Can you try to figure out where it happens? Either by logging, or by debugging.

You can try to print using either the logger module, either with RTT or UART on the nRF52 DK connected to the pot. You can try to log both the values you get from the SAADC, and the values that you are sending over the Nordic UART Service (NUS) over BLE on the first DK.

Are you able to find out where the 0's (small negative) are introduced? Are they coming from the SAADC?

Best regards,

Edvin