Repeating Chip Select Line Pulse

RE: Repeating Chip Select Line Pulse

Edvin — Tue, 21 Apr 2020 23:05:41 GMT

No worries. I am glad to hear that you found the source of the issue! 🙂

Best regards,

Edvin

RE: Repeating Chip Select Line Pulse

jemiaha — Tue, 21 Apr 2020 20:47:49 GMT

Thanks for the reply Edvin. The second image is from a wider time scale. The issue is resolved though. Even though I'd checked to make sure there wasn't another part of the SW using that pin I checked again and found it. In my defense, it wasn't a direct pin assignment repetition. This project uses the SAADC as well and the setup code for that was still referencing the pins from the previous board revision. It was using an NRF_SAADC_INPUT_AINX macro and thus wasn't in the pin map file. So every time the SAADC used the pin it would pulse the CS line. Totally my own fault. Sorry for the false alarm.

RE: Repeating Chip Select Line Pulse

Edvin — Tue, 21 Apr 2020 14:13:48 GMT

Hello,

I don't see the correlation between the first and second image from the logic analyzer? When does it start doing the pulses? Are you sure the pin isn't being used by something else? (I don't have a logic analzer in the home office these corona times, so I can't check).

However, can you try to set the SS/CS pin to NRF_DRV_SPI_PIN_NOT_USED, and control it manually from the application? You must set it as an output pin, set it to low before you send, and set it back up. Does it still do the dips every 1ms then?

RE: Repeating Chip Select Line Pulse

jemiaha — Mon, 20 Apr 2020 22:31:31 GMT

I should add that I'm using the 15.2.0 version of the SDK (for legacy reasons). It's in the tags but this is on the nRF52840.