Notes on using a Raspberry Pi Zero 2w as a headless plexamp client

gistfile1.txt

# Headless Plexamp setup with an RPI0-2w

## Hardware
* RPI-0 2w
* USB soundcard (Fosi Audio MC331 in my case)

## Goal
* Teeny-tiny player to use as a streaming target for plexamp and airplay

## OS
* Raspberry Pi OS Lite (64bit)
Do a regular install, get your Pi on the network and normally operational.

## Software Prereqs
### NodeJS 20
```bash
# Add Node repo, keys and set version
curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/nodesource.gpg
echo "deb [signed-by=/usr/share/keyrings/nodesource.gpg] https://deb.nodesource.com/node_20.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
sudo apt update
sudo apt install -y nodejs
```

### Shairport-sync (for Airplay if you want it)
```bash
sudo apt update
sudo apt install -y shairport-sync
```

### Plexamp
1. Grab the headless plexamp package, move it to your RPI
2. Unpack it, your homedir is fine
```bash
curl -o plexamp-headless.tar.bz2 https://plexamp.plex.tv/headless/Plexamp-Linux-headless-v4.12.4.tar.bz2
tar -xjvf plexamp-headless.tar.bz2
```
3. Edit plexamp/plexamp.service
   a. Change all instances of /home/pi to match your own username eg: /home/my_user
4. Copy the plexamp.service file to /etc/systemd/system
5. Enable and start the service: `sudo systemctl daemon-reload && sudo systemctl enable plexamp`

### IMPORTANT: Fix the USB audio on the Pi
The default config for the zero 2 pi enables the HDMI audio channel, we need to fix this
```bash
# Edit the config.txt
sudo vi /boot/firmware/config.txt

# Disable the onboard audio:
# Comment out the line dtparam=audio=on -> #dtparam=audio=on
# Change the HDMI driver to disable the audio channel:
# dtoverlay=vc4-kms-v3d -> dtoverlay=vc4-kms-v3d,noaudio
```
Restart the Pi

### Plexamp setup
1. Go to https://plex.tv/claim and get a claim token
2. Go to your home directory and run: `node plexamp/js/index.js`
3. Enter your claim code there.  You should be ready

### Final Thoughts
You should now be able to run `lsusb` and see your USB soundcard, `aplay -l` should also list your device
If you can't see them, you need to troubleshoot USB issues: 
Is the cable you used charge only? 
Did you plug your usb cable into the usb port closest to the HDMI connector? (The other is power only)

That's it, have fun.