Pico et al sound output | adafruit | Page 1

wary rune Jun 10, 2023, 5:02 PM

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Coming back to this a bit later, stumbled across the RP2040 hardware design guide https://datasheets.raspberrypi.com/rp2040/hardware-design-with-rp2040.pdf pg23 which has a simple audio circuit for driving things in what's likely a more appropriate way:

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Tried it without the external supply/logic buffer, and works pretty well. Seemed like there was a bit of static at very low volume levels/off, but maybe that's a consequence of not using the pristine supply.

lofty rose Jun 10, 2023, 5:21 PM

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Yeah that's probably just a limitation of the PWM outputs and the filter's ability to smooth low duty cycle signals.

wary rune Jun 10, 2023, 6:27 PM

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Wonder if there's a software method for automatically turning the PWM off when the volume is too low.

#Pico et al sound output