These are brief notes and are not intended to be a full tutorial. A simpler version of this code is explained in detail here:
The project contains 2 directories.
The web-server directory contains the main web application. Install this on your main computer in a directory called web-server. Your main computer could be a Windows PC or Mac or Linux or Raspberry Pi. You can attach a camera to it (a standard webcam or a Raspberry Pi camera for the Raspberry Pi) if you want to stream a view of the robot room.
The robot directory contains the code for the robot. Install this on each Raspberry Pi robot you want to control in a directory called robot. The mqtt_robot.py version is for "standard" Raspberry Pi robots, and uses the gpiozero Robot class. The mqtt_picon_robot.py version is a version for use with the Picon Zero motor controller.
Follow the setup instructions here to install Mosquitto and Paho:
Edit the settings in web_site_settings.py.
Find the following lines in the Global objects section of the code:
robots = {"petra":None, "betty":None}
# List of cameras
cameras = {"Main":"/video", "Rear":"http://petra:5001/video"}
Enter the name of your robots and the URL of your additional cameras. Leave the main camera as-is. Note that when you test this locally and connected to the internet the URLs will be different.
In web_site.py you can change between a standard webcam
from webcam_player import VideoPlayer
and a Raspberry Pi Camera:
from pi_camera_player import VideoPlayer
Start the web application by running:
python3 web_site.py
Then from a browser you can browse to the main page:
http://localhost:5000/
To get the admin screen:
http://localhost:5000/admin
You can install additional cameras, on different machines around the room. On each computer running additional cameras, run:
python3 streamvideo.py
Note that you can alter the code to rotate the camera, change the resolution, etc.
As well as Raspberry Pi cameras, you can use webcams. For this, you will need to comment out the line that imports from pi_camera_player and uncomment the line that uses webcam_player. Note that you will need to install OpenCV for this to work.
The URL for the camera needs to be added to the cameras dictionary in web_site_settings.py.
Note that you can alter the code to rotate the camera, change the resolution, etc.
On each robot, edit mqtt_robot.py or mqtt_picon_robot.py. Find these lines:
MQTT_BROKER = "web-server" # Change to name of your broker MQTT_TOPIC = "robots/clarissa" # Change to name of your topic
Change the name "web-server" to the name or IP address of your web server.
Change the name "clarissa" to the name of this robot.
Start the robot:
python3 mqtt_robot.py
or
python3 mqtt_picon_robot.py
Run streamvideo.py on the robot. Change the camera config if required in pi_camera_player.py.
Note that to reduce bandwidth use, use the lowest quality settings on the robot camera. These are fine:
RESOLUTION = (160,120) JPEGQUALITY = 10 FPS = 5
Add the camera to the cameras dictionary in web_site_settings.py.
The best way to do this is to set up a DMZ or port forwarding on your router. Otherwise you could use a service like ngrok.
The easiest way to manage the robot is to set up a service that starts when the robot starts.
Create /usr/bin/runrobot.sh and add the following
DATE=`date '+%Y-%m-%d %H:%M:%S'`
echo "Myservice service started at ${DATE}" | systemd-cat -p info
python3 /home/pi/web-controlled-robot-full/robot/mqtt_picon_robot.py &
python3 /home/pi/web-controlled-robot-full/web-server/streamvideo.py
sudo chmod +x /usr/bin/runrobot.sh
Create /etc/systemd/system/runrobot.service and add the following:
[Unit] Description=Web robot systemd service. [Service] Type=simple User=pi ExecStart=/bin/bash /usr/bin/runrobot.sh [Install] WantedBy=multi-user.target
Create /etc/systemd/system/runrobot.timer and add the following:
[Unit] Description=Load network drive with delay [Timer] OnBootSec=1min [Install] WantedBy=timers.target
Enable the timer:
sudo systemctl enable myservice.timer
Reboot the Pi.