Transform your Raspberry Pi Zero W with Pirate Audio HAT into a Bluetooth audio receiver for any stereo system.

• Raspberry Pi Zero W (original with BCM2835)
• Pimoroni Pirate Audio HAT (any variant with headphone amp)
• MicroSD card (8GB minimum)
• Power supply (5V 2A recommended)
• 3.5mm audio cable (to connect to your stereo)

• Raspberry Pi OS Lite (Legacy, 32-bit) - based on Debian Bullseye
• SSH enabled
• WiFi configured

Use Raspberry Pi Imager to flash the SD card:

1. Choose Device: Raspberry Pi Zero
2. Choose OS: Raspberry Pi OS (other) → Raspberry Pi OS Lite (Legacy, 32-bit)
3. Choose Storage: Your SD card
4. Configure Settings (click gear icon):
   • Set hostname: pi or bt-receiver
   • Enable SSH with password authentication
   • Set username: pi and password
   • Configure WiFi (SSID and password)
   • Set locale and timezone

1. Insert SD card into Pi Zero W
2. Power it on and wait ~60 seconds for first boot
3. Connect via SSH:

   ssh pi@pi.local
   # or
   ssh pi@<IP_ADDRESS>

Copy the script to your Pi and run it:

# From your computer
scp setup-bt-receiver.sh pi@pi.local:~

# SSH into the Pi
ssh pi@pi.local

# Run the setup script
bash setup-bt-receiver.sh

The script will:

• Update system packages
• Install Pirate Audio HAT drivers
• Install and configure Bluetooth and PulseAudio
• Set up automatic Bluetooth discovery
• Create systemd service for auto-start on boot
• Configure the device as "BT-Audio-Receiver"

After the script completes, reboot when prompted:

sudo reboot

1. Open Bluetooth settings on your phone
2. Search for available devices
3. Connect to "BT-Audio-Receiver" or "pi"
4. Pair (no PIN required)
5. Play audio - it will output through the Pirate Audio HAT

• The Pi will remain discoverable at all times
• Previously paired devices will automatically reconnect
• Only one device can stream audio at a time
• Audio quality: 44.1kHz/48kHz, 16-bit stereo

Check if Bluetooth is powered and unblocked:

# Check rfkill status
sudo rfkill list

# Unblock if necessary
sudo rfkill unblock bluetooth

# Power on Bluetooth
bluetoothctl power on
bluetoothctl discoverable on
bluetoothctl pairable on

# Check status
bluetoothctl show

Should show:

• Powered: yes
• Discoverable: yes
• Pairable: yes

Check if Pirate Audio HAT is detected:

# List audio devices
aplay -l
cat /proc/asound/cards

# Should show "sndrpihifiberry" or similar, not just HDMI

If HAT not detected, verify /boot/firmware/config.txt:

sudo nano /boot/firmware/config.txt

Ensure these lines exist:

#dtparam=audio=on    # Must be commented out
dtoverlay=hifiberry-dac
gpio=25=op,dh

Then reboot:

sudo reboot

Set the correct default audio device:

# Check current sinks
pactl list sinks short

# Set HiFiBerry as default
pactl set-default-sink <SINK_NUMBER_OR_NAME>

Or configure ALSA default:

sudo tee /etc/asound.conf > /dev/null <<EOF
pcm.!default {
    type hw
    card 0
}
ctl.!default {
    type hw
    card 0
}
EOF

Monitor Bluetooth events in real-time:

bluetoothctl
# Watch for connection attempts and errors

Check service status:

# Bluetooth service
sudo systemctl status bluetooth

# Audio receiver service
sudo systemctl status bt-audio-receiver

# View recent logs
journalctl -u bt-audio-receiver -n 50

# Check status
pulseaudio --check && echo "Running" || echo "Not running"

# Restart PulseAudio
pulseaudio --kill
pulseaudio --start

# Check for errors
journalctl --user -u pulseaudio -n 50

# Make discoverable again
bluetoothctl discoverable on

# List paired devices
bluetoothctl devices

# Remove a device
bluetoothctl remove <MAC_ADDRESS>

# Trust a device (auto-reconnect)
bluetoothctl trust <MAC_ADDRESS>

# Check Bluetooth service
sudo systemctl status bluetooth

# Check receiver service
sudo systemctl status bt-audio-receiver

# Restart receiver service
sudo systemctl restart bt-audio-receiver

# View logs
journalctl -u bt-audio-receiver -f

# Test audio output
speaker-test -c2 -t wav

# List audio devices
aplay -l

# Check PulseAudio sinks
pactl list sinks short

# Monitor audio routing
pactl list sinks

• Bluetooth config: /etc/bluetooth/main.conf
• Boot config: /boot/firmware/config.txt
• PulseAudio user config: ~/.config/pulse/client.conf and ~/.config/pulse/default.pa
• PulseAudio system config: /etc/pulse/default.pa
• Bluetooth service: /usr/local/bin/bt-speaker-init.sh
• Systemd service: /etc/systemd/system/bt-audio-receiver.service

Edit the init script:

sudo nano /usr/local/bin/bt-speaker-init.sh

Change this line:

hciconfig hci0 name "BT-Audio-Receiver"

Then restart:

sudo systemctl restart bt-audio-receiver

Edit PulseAudio config:

nano ~/.config/pulse/default.pa

Modify:

default-sample-format = s16le      # or s24le for 24-bit
default-sample-rate = 44100        # or 48000
alternate-sample-rate = 48000      # or 96000

Restart PulseAudio:

pulseaudio --kill
pulseaudio --start

To remove the Bluetooth receiver setup:

# Stop and disable services
sudo systemctl stop bt-audio-receiver
sudo systemctl disable bt-audio-receiver

# Remove files
sudo rm /etc/systemd/system/bt-audio-receiver.service
sudo rm /usr/local/bin/bt-speaker-init.sh

# Reload systemd
sudo systemctl daemon-reload

# Optional: Remove packages
sudo apt-get remove --purge bluez pulseaudio pulseaudio-module-bluetooth

The Raspberry Pi Zero W has limited resources:

• Single-core 1GHz CPU
• 512MB RAM
• Bluetooth 4.1

Expected performance:

• ✅ Streaming from phone/tablet
• ✅ Standard audio quality (44.1kHz/48kHz)
• ✅ Low latency for music playback
• ⚠️ High-res audio may have dropouts
• ⚠️ Multiple simultaneous connections not supported

• The device is always discoverable (no timeout)
• Auto-pairing is enabled (no PIN required)
• Consider setting DiscoverableTimeout in /etc/bluetooth/main.conf for better security
• Add PIN pairing by changing the agent type in the init script

MIT License - Feel free to modify and distribute

• Pimoroni for the Pirate Audio HAT
• Raspberry Pi Foundation
• BlueZ Bluetooth stack
• PulseAudio project

For issues or questions:

1. Check the Troubleshooting section
2. Review system logs: journalctl -xe
3. Check Pimoroni support forums
4. Verify hardware connections

• v1.0 - Initial release with automatic setup script
  • Bluetooth audio receiver functionality
  • Pirate Audio HAT support
  • Auto-discovery and pairing
  • Systemd service for persistence