In this lesson, we will show you how to use Python3 Flask and M-Jpeg Streamer software to control a Raspberry Pi Robot Car through Internet. You will monitor the car’s real-time movement through its’ eye(front camera).

Step 1: You must complete and test lesson 2 before you continue on with this lesson , then install a new SG90 blue servo onto the servo position. Connect SG90 servo to PCA9685 port 14.

Step 2: Choose slotted bracket in servo motor to cross Camera holder from top to bottom and fix blade with M1.5*6 Self Tapping Screws

Step 3: Install CSI camera to holder with 4pcs M2 push pin rivets

Step 4: Install Camera holder on servo motor with 1pc M2*4 Self Tapping Screws

Servo Must be installed and connected PCA9685 PWM 15 port and connect CSI camera to CSI Slot of Raspberry Pi with CSI ribbon cable (Please pay attention the connections of the cable before you install it.)

Step 1: Please enable Camera in Raspberry Pi by typing following command

sudo raspi-config

Then select ->5 Interfacing Options->P1 Camera->Yes->Ok->Finish (Please reboot the raspberry pi according to the notice.)

Step 2: Type following command to install mjpeg-streamer software :

wget http://osoyoo.com/driver/picar/webcam.sh


and then type the following command:

wget http://osoyoo.com/driver/picar/camstart.sh

and type the following command at last:

bash webcam.sh

After running above commands, mjpeg-streamer software is installed in your raspberry pi. So Simple!

Step 3: Start  jpeg-streamer server in your Raspberry Pi
Run following command in your Pi terminal will start your mjpeg-streamer server

bash camstart.sh

These message means your video server is running at port 8899 in your Pi.

Step 4: Now we can use your browser to test the surveillance video. Now please visit http://your_raspberry_pi_ip:8899 (in our sample case http://192.168.0.34:8899),

click stream link or direct visit http://your_raspberry_pi_ip:8899/?action=stream, you will see the video surveillance.

Step 5: Open a new terminal window and run the following code to install the OSOYOO web camera controlled robot car software

wget http://osoyoo.com/driver/p3-car/piwebcar.sh


and then type the following command:

bash piwebcar.sh

Step 6: type following command to enter the folder osoyoowebcar

cd piwebcar

Step 7: Then type the following command to edit the file webcar.py

nano webcar.py

Replace ip address 192.168.0.34 in line 15 to your raspberry pi IP address, and cick “Ctrl”+”X” then “Y” to save the file and then click “enter” to exit

Step 8: Then type the following command to edit the file templates/index.html

nano templates/index.html

Please change 192.168.0.34 in line 34 to your pi’s ip address, and cick “Ctrl”+”X” then “Y” to save the file and then click “enter” to exit

Step 9: Run the code by typing command

sudo python ~/piwebcar/webcar.py

Step 10: In your PC or cell phone which is the same wifi network of your Raspberry Pi, open the browser and visit http://your_RaspberryPi_ip_address, you will see following UI

The arrows buttons are direction control keys, red circle button in the middle is the STOP key. There are four speed control buttons in the bottom:

In the top of the page, there is a Camera Direction Slider, you can move the slider in order to rotate the servo and change the camera orientation.

Before the upper Arrow button, there is a Steer Direction Slider, you can move this slider to rotate your front wheel (just like rotate your steering wheel when driving a car).

Reference:
Marcelo Rovai : Python WebServer With Flask and Raspberry Pi
https://towardsdatascience.com/python-webserver-with-flask-and-raspberry-pi-398423cc6f5d