Verdens beste effektpedal!

En (bærbar) effektboks for gitar som skal kjøre på en Raspberry Pi. Skal ha input for gitar og output for hodetelefon. Prosesserer signaler i real time.

Plan

• Finne et audio interface for Raspberry Pi slik at man kan få gitar-input.
• Finne ut hvordan man leser ut samples fra audio interface-et.
• Få til å spille ut lyden i real time
• Legge inn mulighet for å prosessere lyd med diverse moduler / plug-ins

Effektidéer

• Delay
• Looper
• Multitap delay
• Reverb
  • C++ Reverb – DSP Final Project)
  • Paper
• Fuzz!
• Flanger

Oppsett av raspberry pi'en

https://gist.github.com/torgeir/688369351d91152a3c63a4e51135f661

Ressurser / lenker

• https://forum.juce.com/t/audio-thru-xlr-cable-into-raspberry-pi/35452
• https://github.com/iPlug2/iPlug2OOS - alternativ til juce
• http://www.audioinjector.net/rpi-ultra
• https://www.amazon.com/dp/B01N905VOY
• https://github.com/Streampunk/naudiodon#readme
• http://www.portaudio.com/
• https://wiki.linuxaudio.org/wiki/raspberrypi

Build the base image

DOCKER_HOST=ssh://pi4 docker build -f Dockerfile.base -t <dockerhub-username>/effektpedal:latest

Remember to update the Dockerfile.effektpedal to depend on this image ☝️

Push it to dockerhub

DOCKER_HOST=ssh://pi4 docker push torgeir/effektpedal:latest

Run on Raspberry PI

Build the local code on the pi:

DOCKER_HOST=ssh://pi4 docker build -f Dockerfile.effektpedal -t compiled

To run it:

DOCKER_HOST=ssh://pi4 docker run --device=/dev/snd:/dev/snd compiled

Build and run on the pi:

DOCKER_HOST=ssh://pi4 docker build -f Dockerfile.effektpedal -t compiled . \
&& DOCKER_HOST=ssh://pi4 docker run --device=/dev/snd:/dev/snd compiled

To debug in a shell:

DOCKER_HOST=ssh://pi4 docker run --device=/dev/snd:/dev/snd -it --entrypoint /bin/bash compiled

Make it persistently run on PI boot

DOCKER_HOST=ssh://pi4 docker run -d --restart=always --name effektpedal --device=/dev/snd:/dev/snd compiled

To make redeploy possible, run this first

DOCKER_HOST=ssh://pi4 docker rm effektpedal

All in one go

DOCKER_HOST=ssh://pi4 docker stop effektpedal; \
  DOCKER_HOST=ssh://pi4 docker rm effektpedal; \
  DOCKER_HOST=ssh://pi4 docker build -f Dockerfile.effektpedal -t compiled . \
  && DOCKER_HOST=ssh://pi4 docker run -d --name effektpedal --restart=always --device=/dev/snd:/dev/snd compiled

Troubleshooting

Kill the running container:

DOCKER_HOST=ssh://pi4 docker stop $(docker ps | tail -n 1 | awk '{print $1}')

Debug docker image size

ncdu -X .dockerignore

Prune all images

docker images prune -f

Its rediculously loud!?

amixer sset 'Master' 50%
amixer sset 'Capture' 50%
sudo alsactl store