HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

RE: HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

MartinBL — Mon, 09 Oct 2017 07:20:57 GMT

Yes, RTT and UART should work.

RE: HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

nithin — Mon, 09 Oct 2017 07:16:10 GMT

OKay. How can I see that raw PCM data from RAM , could I use RTT or UART for that ?

RE: HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

MartinBL — Mon, 09 Oct 2017 07:00:52 GMT

The output of the PDM module is raw PCM data which is stored in buffers in RAM. The buffers can be as long as you want (as long as they fit in RAM of course). Nordic doesn't provide any solution for converting PCM to audio files, so I suggest you look for that somewhere else. Converting PCM to WAV seems to be a matter of generating a proper file header and place it before your raw PCM data: Link.

RE: HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

nithin — Sat, 07 Oct 2017 10:24:52 GMT

hai Martin, thanks for your response. I have some doubts whether these buffers ( m_cb.buffers[1],m_cb.buffers[0]) holds actual pdm out i.e PCM ? and its buffer size(in RAM). How to convert this pcm data to wav or any other audio formate?. I want to analyze a particular range of sound from this mic (spk0838ht4h-b).

RE: HOW TO ANALYSIS PDM DATA CONTINUOUSLY IN NRF52832

MartinBL — Fri, 06 Oct 2017 12:13:12 GMT

Hi, I'm not sure if I understand your problem. You provide a buffer to the PDM module, and the PDM then gathers data in the background. When the buffer is full you process it. This is achieved with the EasyDMA feature and the data is always stored in RAM. Unfortunately there are no PDM examples, but here is the documentation of the PDM drivers.