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

Am I the only one who gets regurarly status_code:204 error messages? It's totally random, usually I have to restart the service every day. Sometimes it works for 10 hours, sometimes for 40 hours. Do you have any idea how can I fix this?

sudo systemctl status prusaconnect_upload_cam.service
● prusaconnect_upload_cam.service - Raspi Cam to Prusa Connect
Loaded: loaded (/etc/systemd/system/prusaconnect_upload_cam.service; enabled; preset: enabled)
Active: active (running) since Fri 2025-02-07 19:03:31 CET; 2 days ago
Main PID: 27648 (prusaconnect_up)
Tasks: 2 (limit: 1568)
CPU: 2h 3min 53.964s
CGroup: /system.slice/prusaconnect_upload_cam.service
├─27648 /bin/bash /usr/local/bin/prusaconnect_upload_cam.sh
└─29610 curl -k -X PUT https://connect.prusa3d.com/c/snapshot -H "accept: /" -H "content-type: image/jpg>

Feb 09 18:53:19 raspberrypi prusaconnect_upload_cam.sh[29485]: {"status_code":204}
Feb 09 18:53:42 raspberrypi prusaconnect_upload_cam.sh[29496]: {"status_code":204}
Feb 09 18:54:20 raspberrypi prusaconnect_upload_cam.sh[29507]: {"status_code":204}
Feb 09 18:55:11 raspberrypi prusaconnect_upload_cam.sh[29518]: {"status_code":204}
Feb 09 18:55:44 raspberrypi prusaconnect_upload_cam.sh[29531]: {"status_code":204}
Feb 09 18:56:52 raspberrypi prusaconnect_upload_cam.sh[29542]: {"status_code":204}
Feb 09 18:57:28 raspberrypi prusaconnect_upload_cam.sh[29553]: {"status_code":204}
Feb 09 18:58:23 raspberrypi prusaconnect_upload_cam.sh[29564]: {"status_code":204}
Feb 09 18:58:50 raspberrypi prusaconnect_upload_cam.sh[29576]: {"status_code":204}
Feb 09 18:59:19 raspberrypi prusaconnect_upload_cam.sh[29587]: {"status_code":204}

@domosgabor So a 204 isn't an error in the HTTP world: it's a success and just the server saying "I have nothing to return": https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/204 Do you find that once the 204s start showing up that your webcam images don't update on the Prusa site?

@domosgabor So a 204 isn't an error in the HTTP world: it's a success and just the server saying "I have nothing to return": https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/204 Do you find that once the 204s start showing up that your webcam images don't update on the Prusa site?

Thanks for the clarification. Exactly as you said, the camera stops updating after getting 204 status code.

So it's not an error, but how can I investigate why the image is not updating?