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Jscott44 / RTEP5-the-raspberry-jam

Realtime digital guitar effects pedal designed for Raspberry PI, written in C++
MIT License
12 stars 0 forks source link

PiGPIO Conflicts with PCM devices #97

Open Jscott44 opened 5 months ago

Jscott44 commented 5 months ago

By default PiGPIO uses the PCM clock (and thus the pins) to establish timing. Most audio devices use the PCM pins also. One can configure PiGPIO to use the PWM clock instead, however it appears the internal sound card on the RPI also uses the PWM clock. Thus, PiGPIO can only be used with using a full duplex sound card on PCM pins and configuring PiGPIO to use the PWM clock.

iamdario commented 5 months ago

After further testing, we have discovered that the physical button component of The Raspberry Jam would likely not work even with a full duplex sound card. This is because, in order for the button to work, the library being used to read the GPIO pins (PiGPIO) would require SU privileges. However, it has been found that ALSA is unable to function when given SU privileges. This hypothesis was confirmed by the following forum: Link.

Until a work around is found, this project will move towards implementing a digital button using the GUI.