nRF52832/QFAAB0- can't get all SAADC channel data in scanning mode

RE: nRF52832/QFAAB0- can't get all SAADC channel data in scanning mode

Jørgen Holmefjord — Wed, 24 Jan 2018 13:13:01 GMT

Could you give some more details on what you are expecting to see, what you are seeing, and some measurements from all the channels? Can you also provide simplified example that reproduces this issue, that we can use for debugging?

RE: nRF52832/QFAAB0- can't get all SAADC channel data in scanning mode

kont40 — Tue, 23 Jan 2018 20:56:55 GMT

Hi, thanks for reply. Yes, when all the channels shown above were uncommented (five in total) SAMPLES_IN_BUFFER was set to 5. The problem appeared in that case.

RE: nRF52832/QFAAB0- can't get all SAADC channel data in scanning mode

Jørgen Holmefjord — Sun, 21 Jan 2018 22:33:29 GMT

Did you increase the size of SAMPLES_IN_BUFFER when you enabled more than two channels? Note this part from the SAADC documentation:

In Scan mode, the size of the Result buffer must be large enough to have room for a minimum one result from each of the enabled channels. To secure this, RESULT.MAXCNT must be specified to RESULT.MAXCNT >= "number of channels enabled". See Scan mode for more information about Scan mode.

You need to set the buffer to N times the number of activated channels to get correct results.