Beatnik Knob - Beatnik & Snapcast Client Volume Controller

A hardware volume controller for Snapcast using a rotary encoder on Raspberry Pi.

Hardware Wiring

Connect your rotary encoder to the Raspberry Pi:

Rotary Encoder	Raspberry Pi GPIO	Pin
CLK	GPIO 17	11
DT	GPIO 18	12
SW (Button)	GPIO 27	13
VCC	3.3V	1
GND	Ground	6

Installation

You can install the necessary packages and set up permissions by running the installation script.

# Make the script executable
chmod +x install.sh

# Run the installation script
sudo ./install.sh

After the script completes, you will need to reboot your Raspberry Pi for the permission changes to take effect.

For manual installation steps, please see the INSTALL.md file.

4. Configure Snapcast Connection

# Edit the main script
nano rotary/snapcast-volume-rotary.py

Update these variables:

• SNAPCAST_URI = "ws://YOUR_SERVER_IP:1780/jsonrpc"
• SNAPCAST_CLIENT_ID = "YOUR_CLIENT_ID"

Find your client ID:

curl -s http://YOUR_SERVER_IP:1780/jsonrpc \
  -d '{"id":1,"jsonrpc":"2.0","method":"Server.GetStatus"}' | \
  jq '.result.server.groups[].clients[].id'

5. Test Hardware

# Test rotary encoder wiring
cd rotary
python3 rotary-encoder-test.py

6. Run Volume Controller

# Start the controller
python3 snapcast-volume-rotary.py

Optional: Run as System Service

Create service file:

sudo nano /etc/systemd/system/beatnik-knob.service

Add this content:

[Unit]
Description=Beatnik Knob Volume Controller
After=network.target

[Service]
Type=simple
User=pi
WorkingDirectory=/home/pi/beatnik-knob/rotary
ExecStart=/usr/bin/python3 snapcast-volume-rotary.py
Restart=always

[Install]
WantedBy=multi-user.target

Enable and start:

sudo systemctl daemon-reload
sudo systemctl enable beatnik-knob.service
sudo systemctl start beatnik-knob.service

Troubleshooting

Permission errors: Make sure you logged out and back in after adding user to gpio group

Import errors:

sudo apt install --reinstall python3-gpiozero python3-websockets

Connection errors: Verify Snapcast server IP and that port 1780 is accessible

Service logging and debugging:

# Check service status
sudo systemctl status beatnik-knob.service

# View recent logs
journalctl -u beatnik-knob.service -n 50

# Follow logs in real-time
journalctl -u beatnik-knob.service -f

# View logs from today
journalctl -u beatnik-knob.service --since today

# View logs with timestamps
journalctl -u beatnik-knob.service -o short-iso

# Restart service and watch logs
sudo systemctl restart beatnik-knob.service && journalctl -u beatnik-knob.service -f