MicroPython Forum (Archive)

Thanks, yes, understand that as they're unsigned 12-but values (0 - 4095). I'm seeing a significant offset with the AMP Audio skin, with a somewhat noisy silence hovering anywhere between 2,400 to 3,000. I can compensate for this in post-processing but it would be nice to be able trim it out.

Thanks, that's to be suspected I guess - they're general-purpose ADCs and it's up to you to decide how to use it and provide any filtering. I don't have access to the AMP Audio skin design, I just assume that as it's using a _microphone_ that some sort of low-pass filter (maybe as low as 4kHz) is on...

Is there any low-pass filtering in front of the ADC either on the pyboard or the AMP Audio skin? I'm sampling at audio rate (6-8kHz) and just wondered whether any low-pass filter exists before the digital sampling?

Thanks. It's working now, even though I'm seeing a significant DC offset using the AMP Audi skin - but that's a separate issue! Thanks.

Wow - can'y anybody answer this? Can you do an adc.read() from within an ISR? I'll update to latest drivers but if you can't access the h/w from an ISR, mmmm.

I can read the AMP skin microphone using a timed read and I can seem to read values individually using adc.read() from the prompt. But, I need to read at an interrupt-driven rate (6kHz). I've tried everything but seem to get weird (max) values doing adc.read() from an ISR. Can you do an adc.read() f...