ADC @ 4kHz with BLE running in parallel

RE: ADC @ 4kHz with BLE running in parallel

Jared — Fri, 22 Mar 2024 10:15:10 GMT

Hi,

The new SAADC driver v2 has a fix for the buffer swap issue, if you use nrfx driver directly then it will use this instead of the legacy driver. I'm not quite sure whether the Zephyr API use the legacy or the v2 driver but I think it use the latter.

Anyhow, at 4 kHz, I don't think it will be a problem at all.

regards

Jared

RE: ADC @ 4kHz with BLE running in parallel

Nathan O. — Fri, 22 Mar 2024 09:28:29 GMT

I am not sure which one I will be using but I guess I'll try to use the Zephyr ADC API. What would be the situation in both case ?

RE: ADC @ 4kHz with BLE running in parallel

Jared — Fri, 22 Mar 2024 09:17:47 GMT

Hi,

I see, are you using the nrfx SAADC driver directly or are you using the Zephyr ADC API?

regards

Jared

RE: ADC @ 4kHz with BLE running in parallel

Nathan O. — Thu, 21 Mar 2024 22:27:07 GMT

Thanks.

No it is a new project, I will be using nrf Connect SDK. Not sure how those apply then with NCS.

I really need the order of the adc samples to be right.

RE: ADC @ 4kHz with BLE running in parallel

Jared — Thu, 21 Mar 2024 12:21:39 GMT

Hi,

Are you using nRF5SDK?

I think at 4 kHz it should be fine but this (nRF5SDK) can be a concern when using Bluetooth and ADC together. In that the buffer samples might change order if the processing and setting up new buffers are interrupted by the Softdevice. The ADC on the nRF5840 use EasyDMA so the data will not be lost if a BLE event interrupts the processing of the data. If you're using nRF5SDK then you can find a sample here,

regards
Jared