CONFIGURE_BLUETOOTH_PRINTER.md

Configure for Bluetooth Printer

The Issue

The app is trying to use USB printer, but you have a BLUETOOTH printer.

Solution: Change Configuration

Step 1: Edit app.py on Raspberry Pi

# SSH to Pi
ssh [email protected]

# Go to app directory
cd /boot/firmware

# Edit app.py
sudo nano app.py

Step 2: Change Printer Type

Find line 18 (around there):

PRINTER_TYPE = os.getenv('PRINTER_TYPE', 'usb')

Change to:

PRINTER_TYPE = os.getenv('PRINTER_TYPE', 'bluetooth')

Also check line 21 (SERIAL_PORT):

SERIAL_PORT = os.getenv('SERIAL_PORT', '/dev/rfcomm0')

This should already be /dev/rfcomm0 which is correct for Bluetooth.

Save: Ctrl + X, Y, Enter

Step 3: Set Up Bluetooth Connection

Make sure Bluetooth is paired and connected.

Check if printer is paired:

bluetoothctl
devices
# Should show your printer
exit

If not paired, pair it:

# Enter bluetoothctl
bluetoothctl

# Scan for devices
scan on
# Wait to see your printer's MAC address

# Pair (replace MAC with your printer)
pair MAC:ADDRESS:OF:PRINTER

# Trust
trust MAC:ADDRESS:OF:PRINTER

# Exit
exit

Bind to serial port:

# Find your printer's MAC address
bluetoothctl devices

# Bind to rfcomm (replace MAC with your printer's MAC)
sudo rfcomm bind /dev/rfcomm0 MAC:ADDRESS:OF:PRINTER

# Verify it's bound
ls -la /dev/rfcomm0

Should show:

crw-rw---- 1 root dialout 216, 0 Oct 27 12:00 /dev/rfcomm0

Step 4: Fix Permissions

sudo chmod 666 /dev/rfcomm0
sudo usermod -a -G dialout pi

You may need to log out and back in for group changes to take effect.

Step 5: RESTART Flask

# Kill Flask
pkill -f app.py

# Start again
python3 app.py

Step 6: Test the Connection

From your Mac:

curl https://your-ngrok-url.ngrok-free.dev/health
   - Replace with your actual ngrok URL

Should return printer_connected: true

Then try submitting a ticket from Netlify!

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Alternative: Set via Environment Variable

Instead of editing the file, you can set environment variable:

# Stop Flask
pkill -f app.py

# Start with Bluetooth config
export PRINTER_TYPE=bluetooth
export SERIAL_PORT=/dev/rfcomm0
python3 app.py

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Quick Checklist

✅ Printer paired with Bluetooth
✅ rfcomm bound to /dev/rfcomm0
✅ Permission set (chmod 666 /dev/rfcomm0)
✅ User in dialout group
✅ app.py changed to 'bluetooth'
✅ Flask restarted
✅ Test from Netlify

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Troubleshooting

"No such file or directory" for rfcomm0

# Bind the port
sudo rfcomm bind /dev/rfcomm0 YOUR_PRINTER_MAC

"Permission denied"

sudo chmod 666 /dev/rfcomm0
sudo usermod -a -G dialout pi
# Log out and back in

"Connection refused"

# Unbind and rebind
sudo rfcomm unbind /dev/rfcomm0
sudo rfcomm bind /dev/rfcomm0 YOUR_PRINTER_MAC

Printer not showing in bluetoothctl

# Make sure Bluetooth is on
sudo systemctl status bluetooth

# Turn on if needed
sudo systemctl start bluetooth
sudo systemctl enable bluetooth