Use Raspberry Pi Camera with Prusa Connect

README.md

Use Raspberry Pi and Pi Cam for Prusa Connect

I couldn't get the script from p123ad to work on my Pi Zero W 2 with Camera Module 3 (all kinds of ffmpeg errors). There are several built-in tools for working with the camera now, so I tried to figure out if I could use one of those instead.

Behold this version, which uses the built-in libcamera-still tool to actually interact with the camera and save a JPEG. That image is then uploaded to Prusa Connect, same as the original script.

Instructions

1. Go to the Cameras section at https://connect.prusa3d.com
2. Add a new camera by clicking "Add new other camera"
3. Copy the generated Token
4. Set up your Pi Zero W 2 with Raspian OS Lite (32-bit) (this may work with other combinations of Pi and OS but I haven't tested)
5. Log into your Pi and create a shell script with sudo nano /usr/local/bin/prusaconnect_upload_cam.sh and swap out connect-token-here in the script example with the Token you copied in step 3
6. Change ownership of the script to the user you log into your pi with, for example if your user is pi then run: sudo chown pi:pi /usr/local/bin/prusaconnect_upload_cam.sh
7. Make the script executable: chmod +x /usr/local/bin/prusaconnect_upload_cam.sh
8. Start the script with /usr/local/bin/prusaconnect_upload_cam.sh

If it works you should see no error messages, and a new image appearing in Prusa Connect every 10 seconds.

Create Autostart Service

To run the script in the background and have it start automatically when your Pi starts:

1. Create the service file with sudo nano /etc/systemd/system/prusaconnect_upload_cam.service, paste the content from below and save.
2. Start the service: sudo systemctl start prusaconnect_upload_cam.service.
3. Check if the service is running with sudo systemctl status prusaconnect_upload_cam.service.
4. Enable the service to run at startup: sudo systemctl enable prusaconnect_upload_cam.service.

prusaconnect_upload_cam.service

[Unit]
Description=Raspi Cam to Prusa Connect

[Service]
ExecStart=/usr/local/bin/prusaconnect_upload_cam.sh

[Install]
WantedBy=multi-user.target

prusaconnect_upload_cam.sh

#!/bin/bash

# Set default values for environment variables
: "${HTTP_URL:=https://connect.prusa3d.com/c/snapshot}"
: "${DELAY_SECONDS:=10}"
: "${LONG_DELAY_SECONDS:=60}"
# FINGERPRINT can be a random string with at least 16 characters
: "${FINGERPRINT:=123456789012345678}"
# CAMERA_TOKEN generated by the Connect server
: "${CAMERA_TOKEN:=connect-token-here}"

while true; do
    # Grab a frame from libcamera-still with the highest resolution
    # that is displayed on Prusa Connect: 1704 x 1278 for a 4:3 image
    # Setting the quality to 80 saves almost 50% in file size for
    # very little decrease in quality. Set to taste!
    # If you need to rotate the image 180° add `--rotate 180`
    # (One user reported needing to make this `--camera.rotate 180` instead!)
    libcamera-still -v 0 --immediate --width 2274 --height 1280 -q 80 -o /tmp/output.jpg

    # If no error, upload it.
    if [ $? -eq 0 ]; then
        # POST the image to the HTTP URL using curl
        curl -k -X PUT "$HTTP_URL" \
            -H "accept: */*" \
            -H "content-type: image/jpg" \
            -H "fingerprint: $FINGERPRINT" \
            -H "token: $CAMERA_TOKEN" \
            --data-binary "@/tmp/output.jpg" \
            --no-progress-meter \
            --compressed

        # Reset delay to the normal value
        DELAY=$DELAY_SECONDS
    else
        echo "libcamera-still returned an error, retrying after ${LONG_DELAY_SECONDS}s..."
        
        # Set delay to the longer value
        DELAY=$LONG_DELAY_SECONDS
    fi

    sleep "$DELAY"
done

Thanks for the snippets, it's very nice !

If you have an error like this when you check the logs of your service:

Jun 06 22:38:10 raspberrypi prusaconnect_upload_cam.sh[3694]: ERROR: *** failed to open file /tmp/output.jpg ***
Jun 06 22:38:10 raspberrypi prusaconnect_upload_cam.sh[3633]: libcamera-still returned an error, retrying after 30s...

You may have some permissions issues in the way your service is set.

Do this instead:

1. Delete and edit your service file
   sudo rm /etc/systemd/system/prusaconnect_upload_cam.service && sudo nano /etc/systemd/system/prusaconnect_upload_cam.service

2. Paste this, change your user name (often pi but can be something else) and save the file

[Unit]
Description=Raspi Cam to Prusa Connect
After=network.target

[Service]
ExecStart=/usr/local/bin/prusaconnect_upload_cam.sh
##################################
### CHANGE TO YOUR USERNAME BELOW  ###
##################################
User=your-username
Environment=XDG_RUNTIME_DIR=/run/user/1000
Restart=always

[Install]
WantedBy=multi-user.target

3. Restart your service

sudo systemctl daemon-reload
sudo systemctl restart prusaconnect_upload_cam.service

4. Check that it works correctly (you should see a 204 server response after a few seconds)

journalctl -u prusaconnect_upload_cam.service -f

5. If it works, set the service to start at boot

sudo systemctl enable prusaconnect_upload_cam.service