Waves aren't actually sines

[litui]

I'm not sure if this is actually repairable as I'm generating and mixing sines in the application code itself, but what's coming out of the Flipper are not clean sines. I've started looking into this and suspect it's due mainly to the generation of audio using PWM on the F0.

Anyway, it means the DTMF, while it sounds good enough, is unlikely to be picked up by actual DTMF detectors as legitimate.

I may experiment with use of square waves instead, which might stand a better chance of surviving the PWM translation.