search

kamilsss655 / ESPRI

ESPRI (ESP Radio Interface) project providing extended functionalities to ham radios
Apache License 2.0
81 stars 3 forks source link

[FEATURE] Sample audio input and encode it as PDM (ADC) #5

Closed kamilsss655 closed 3 months ago

kamilsss655 commented 3 months ago

Is your feature request related to a problem? Please describe.

We need to be able to sample audio inputs as part of building block for digital modes and scrambler.

Describe the solution you'd like

Sample 2 seconds of audio output from radio (via Kenwood connector) using analog comparator of the ESP32 (or other means) and save it as PDM in memory.

Additional context

https://en.wikipedia.org/wiki/Pulse-density_modulation https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/sdm.html https://docs.espressif.com/projects/esp-idf/en/stable/esp32h2/api-reference/peripherals/ana_cmpr.html https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/i2s.html

KDMcMullan commented 3 months ago

I see a ton of things you could do with it ... what's you plan for the feature? Do you know if the ESP can sample at a good audio rate?

kamilsss655 commented 3 months ago

So far I was able to sample audio input at 20kHz, so I assume it could work well. Currently I am a bit stuck because of the internals of ESP-IDF libraries and the resource management (it seems one can only transmit audio or sample audio at a given time).

KDMcMullan commented 3 months ago

Would you want to do both simultaneously? Or are you saying that's two separate software builds needed?

kamilsss655 commented 3 months ago

I don't need to do both at the same time. Although I am having issue switching between rx and tx of audio. It might be I'm doing something wrong, but just in case I opened issue at: https://github.com/espressif/esp-idf/issues/13484

kamilsss655 commented 3 months ago

resolved in v.0.3.8