Intro Fluff

I was using RPi 4 to drive my MK3S+ printers, using the PrusaLink image, one of the great features of PrusaLink is the native support for USB cameras.

I upgraded my Prusa printers from MK3 to MK4, the surprise downside of the upgrade was that suddenly I had nowhere to plug my USB cameras into the Prusa MK4!

Fortunately, Prusa has enabled camera image upload via API.

Prusa Connect - Camera API | Prusa Knowledge Base

Prusa Connect’s Open API allows for seamless integration of third…

Prusa Knowledge Base

Here are the steps I took
My code is available and hosted on GitHub.

GitHub - nickjvturner/prusa-connect-rpi-camera: Scripts to rapidly deploy RPi cameras to feed Prusa Connect

Scripts to rapidly deploy RPi cameras to feed Prusa Connect - nickjvturner/prusa-connect-rpi-camera

GitHubnickjvturner

prusa-connect-rpi-camera

Prusa Connect

Login to Prusa Connect

Navigate to your printer that you want to pair the camera with

Navigate to Camera

+ Add new other camera

Note the Token, We will need that later

Raspberry Pi

Starting with fresh SD image of Bookworm

Update and Upgrade

sudo apt update
sudo apt upgrade -y

Install Python 3 and Pip

Python 3 should be pre-installed, but you may need to install pip for package management

sudo apt install python3-pip -y

Install git

sudo apt install git

Clone this repo

git clone https://github.com/nickjvturner/prusa-connect-rpi-camera

Navigate into the cloned directory

cd prusa-connect-rpi-camera

Create a Virtual Environment

python3 -m venv venv

Activate the Virtual Environment

source venv/bin/activate

Install OpenCV and uuidgen (apt)

sudo apt install python3-opencv -y
sudo apt-get install uuid-runtime

Install requests, OpenCV, Flask (pip3)

pip3 install requests
pip3 install opencv-python
pip3 install flask

Generate a UUID for the camera

The camera requires a UUID, we can generate one using uuidgen

uuidgen

Update secrets.py

Add the freshly created UUID into the secrets.py file
Add the token from earlier to secrets.py

Review code before execution

Quickly skim through:

• pc-cam-local.py
• pc-cam-uploader.py

Test pc-cam-local

You should manually execute/test these scripts, make sure you have activated the virtual environment venv to avoid an error about Flask not being found.

python3 pc-cam-local.py

Check this is working, open up a browser, navigate to the IP address of the Raspberry Pi on port 5000

http://{IP_ADDRESS_OF_YOUR_RPI}:5000

You should see a simple web page displaying frames being captured by your camera.

IP Camera feed

http://{IP_ADDRESS_OF_YOUR_RPI}:5000/video_feed

This URL should serve you only the frames, not embedded within a web page.

IP Camera Viewer

This is the point where you could point an IP camera viewer app at the IP Camera feed URL. I am currently enjoying 'IP Cams'.

‎IP Camera Viewer - IPCams

‎IPCams is a best in class app for viewing your IP security cameras. Connect an ONVIF, RTSP, MJPEG, or HLS camera and view its stream with a beautiful and fluid experience. From the small screen on your wrist to the large screen in your living room, IPCams makes it easy to view your cameras. FEATURE…

App StoreNogosoft LLC

Test pc-cam-uploader

Back to the script testing, pc-cam-local.py should also be writing a .jpg frame to disk every 10 seconds. Check this file is present in your 'prusa-connect-rpi-camera' directory.

latest_frame.jpg

Manually execute pc-cam-uploader.py

python3 pc-cam-uploader.py

If everything is working Prusa Connect should receive the 'latest_frame.jpg'.

Configure scripts to run on boot

Create a service file for pc-cam-local.py

sudo nano /etc/systemd/system/pc-cam-local.service

[Unit]
Description=RPi Camera Local Web Server
After=network.target

[Service]
ExecStart=/home/pi/prusa-connect-rpi-camera/venv/bin/python /home/pi/prusa-connect-rpi-camera/pc-cam-local.py
WorkingDirectory=/home/pi/prusa-connect-rpi-camera
Restart=always
User=pi

[Install]
WantedBy=multi-user.target

Create a service file for pc-cam-uploader.py

sudo nano /etc/systemd/system/pc-cam-uploader.service

[Unit]
Description=Prusa Connect RPi Camera image uploader
After=network.target

[Service]
ExecStart=/home/pi/prusa-connect-rpi-camera/venv/bin/python /home/pi/prusa-connect-rpi-camera/pc-cam-uploader.py
WorkingDirectory=/home/pi/prusa-connect-rpi-camera
Restart=always
User=pi

[Install]
WantedBy=multi-user.target

Enable and start the services

sudo systemctl daemon-reload

sudo systemctl enable pc-cam-local
sudo systemctl start pc-cam-local

sudo systemctl enable pc-cam-uploader
sudo systemctl start pc-cam-uploader

Made changes?

If you git pull and there are changes or you make local changes yourself, you need to stop the related service, reload systemctl daemon and restart the related service

sudo systemctl daemon-reload

sudo systemctl enable pc-cam-local
sudo systemctl restart pc-cam-local

sudo systemctl enable pc-cam-uploader
sudo systemctl restart pc-cam-uploader