ADC can only convert once

RE: ADC can only convert once

Karl Ylvisaker — Mon, 04 May 2020 17:34:36 GMT

Hello again,

I am happy that this resolved your issue!
Yes, buffer_convert must be called in order to continue the sampling - to designate a new buffer for the SAADC to fill.

If you are doing rapid sampling and are worried about loosing a sample between buffers, you might want to use the SAADC's double buffering feature.
The feature is demonstrated in the SAADC peripheral example in the SDK.

Please do not hesitate to open a new ticket if you should encounter any other issues or questions in the future.
Good luck with your development!

Best regards,
Karl

RE: ADC can only convert once

yusuftan — Mon, 04 May 2020 15:26:55 GMT

Hi Karl,

Thank you for your prompt response, as the buffer was declared static, I did not realize that I had to declare a new buffer every time DONE event occurred, so inserting nrf_drv_adc_buffer_convert(.....) at the end of the ADC ISR handler solved the problem.

Best regards,

RE: ADC can only convert once

Karl Ylvisaker — Mon, 04 May 2020 06:24:32 GMT

Hello,

What is your ADC_BUFFER_SIZE?
The DONE event will be triggered when the buffer is full - and then you will need to specify a new buffer for the ADC to start filling.
From the code you have shared it seems that you only call buffer_convert() during adc_config.
You will need to supply a new buffer every time a buffer is filled up, to continue sampling.

For future reference, it is highly beneficial if you would use the "Insert->code" option when sharing code snippets, as it greatly increases readability.

Best regards,
Karl