web-camera_PT

A Raspberry Pi streams MJEPG Video to a Windows PC running a Web Flask server. The server converts the MJPEG stream to .jpg img stream using opencv viewable in Chrome browser. Two RDS3115MG servos connected to the Raspberry Pi are controlled using the Adafruit 16-Channel PWM/Servo Hat. A FOTEK SSR-25DD Solid State Relay is attached directly to the GPIO pin of the Raspberry Pi to control a Water Pump. The servos and the Relay are controllable through MQTT.

On clicking the video stream, you will be able to control the Camera in Pan and Tilt directions and mouse down activates the Water Pump.

Stuff Needed to view camera stream

RPI 3B+ with Bullseye arm64 lite
Raspberry Pi Camera v2.1
Windows Machine
RPI Power Supply

Stuff Needed to pan tilt

RDS3115MG Servo Motors (Or servo motors which are strong enough)
Adafruit 16-Channel PWM/Servo Hat
3D printed parts
Server Running a MQTT Broker
Power Supply for Servo

Stuff Needed to make water turret

12V Portable Agriculture Sprayer
Solid State Relay
3D printed parts
Power Supply for 12V Motors

Setup in RPI

Check if libcamera works/stream setup correctly

Create mjpeg stream
View in windows machine using VLC

Creating mjpeg stream

Run this command on RPI, add -v to view verbose log The IP Address is the RPI's address, so could probably replace this with 127.0.0.1 or localhost, not sure, never tried

Send with 144p

libcamera-vid -t 0 --width 256 --height 144 -q 100 -n --codec mjpeg --inline --listen -o tcp://192.168.XX.XX:XXXX

Send with 240p

libcamera-vid -t 0 --width 352 --height 240 -q 100 -n --codec mjpeg --inline --listen -o tcp://192.168.XX.XX:XXXX

Send with 360p

libcamera-vid -t 0 --width 480 --height 360 -q 100 -n --codec mjpeg --inline --listen -o tcp://192.168.XX.XX:XXXX

Send with 480p (Fails! Not sure why)

libcamera-vid -t 0 --width 858 --height 480 -q 100 -n --codec mjpeg --inline --listen -o tcp://192.168.XX.XX:XXXX
XXX
terminate called after throwing an instance of 'std::runtime_error'
  what():  failed to send data on socket
Aborted

View in Windows using VLC

At this point, the mjpeg stream should be viewable from your Windows PC. Download vlc from https://www.videolan.org/vlc/download-windows.html Navigate to Media > Open Network Stream This is the stream address, the IP Address is the RPI's IP address

tcp/mjpeg://192.168.XX.XXXX:XXXX

You should see the video stream, but it will have a 2 seconds delay. We can reduce this delay by using opencv to read the stream.

Create systemd to auto restart service

Everytime the connection is broken/reset, the libcamera service will die, so these are the steps to set up an auto reset service

cd /lib/systemd/system/
sudo nano libcamera_stream.service

[Unit]
Description=Runs the Libcamera Streaming Service
After=multi-user.target

[Service]
Type=simple
ExecStart=libcamera-vid -t 0 --width 256 --height 144 -q 100 -n --codec mjpeg --inline --listen -o tcp://192.168.XX.XX:XXXX
Restart=on-abort

[Install]
WantedBy=multi-user.target

sudo chmod 644 /lib/systemd/system/libcamera_stream.service
sudo systemctl daemon-reload
sudo systemctl enable libcamera_stream.service
sudo systemctl start libcamera_stream.service
sudo systemctl status libcamera_stream.service

Setup in Windows

Setup Env Variables

Create var to store the address of the rpi Since I use venv, I edit my env/Scripts/activate with export ENV_VAR=XXX to create my env variable Or you can just do export MJPEG_ADDRESS=XXX everytime you create a new terminal

MJPEG_ADDRESS=192.168.XX.XXXX
MJPEG_PORT=XXXX

Install python libraries

Use pip to install flask and opencv-python

pip install flask
pip install opencv-python

If some libraries are missing, just check my requirements.txt

Check if opencv works

Run simple script to view image stream from opencv

python read_mjpeg_opencv.py

Run Flask Server

Chrome does not support showing http mjpeg stream directly. (I think) To view stream in browser, need to convert the mjpeg stream into a browser compatible format The way I did it is to host a server that does the conversion from mjpeg stream into jpg. I wrote app.py that converts it into a constantly updating jpg image

python app_basic.py

$ python app_basic.py 
 * Serving Flask app 'app_basic' (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://127.0.0.1:5000 (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 119-083-471
127.0.0.1 - - [08/May/2022 13:48:47] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [08/May/2022 13:48:47] "GET /static/style.css HTTP/1.1" 304 -
127.0.0.1 - - [08/May/2022 13:48:50] "GET /video_feed HTTP/1.1" 200 -

The site should be accessible on your localhost at http://127.0.0.1:5000

NOTE that if you refresh the page, libcamera will die and need to be restarted.

If you have already setup the systemd service to auto restart it then just need to just refresh the page twice every time.

To allow access to other computers on the same network, you need to set the appropriate firewall rules

netsh firewall add portopening TCP 5000 "WaterTurret"
netsh advfirewall firewall add rule name="WaterTurret TCP Port 5000" dir=in action=allow protocol=TCP localport=5000
netsh advfirewall firewall add rule name="WaterTurret TCP Port 5000" dir=out action=allow protocol=TCP localport=5000

Palt0n/web-camera_PT