The WC-Car is built from an existing RC Car but has been heavily modified. The original control board (reciever, motor control etc.) was removed and replaced with a Raspberry Pi 3, Arduino Uno and a H bridge. The Raspberry Pi recives input from the client via a tcp connection which feeds commands to the Arduino through serial to execute. The Raspberry Pi is also hosting a webcam server. (A Genuino 101 was going to be used, but nampy firmware is not compatible with the x86 architecture.)
DC motors can either go forward or reverse depending on the polarity of the circuit, a H bridge is used to change the polarity and PWM is used to control the speed. The H bridge that was used is a l298n clone. The two input directions are toggled and a PWM signal is sent to the H bridge. Below is an example of the rear motor, the front motor which handles the steering is the exact same.
digitalWrite(REAR_DIR_1, LOW);
digitalWrite(REAR_DIR_2, HIGH);
analogWrite(PWM_REAR, 200);from nanpy import ArduinoApi, SerialManager
connection = SerialManager()
a = ArduinoApi(connection=connection)
a.digitalWrite(REAR_DIR_1, a.LOW);
a.digitalWrite(REAR_DIR_2, a.HIGH);
a.analogWrite(PWM_REAR, 200);This project is being used as my year 12 major IPT project, and I thought it would be an interesting concept to explore.
The Arduino must be running the nanpy firmware which will be linked below with instructions.
The Motion package must be installed which can retrieved through apt-get to host a webcam server. Apache is optional but it can be used to make a nicer looking website with the webcam stream embedded.
The Raspberry Pi must be running Python 3.5.x as the server is written is Python 3.5
The Reaspberry Pi must have the nanpy package installed
The client is also written in Python 3.5 just like the server meaning Python 3.5.x must be installed
The OpenCV2 python 3 library if you would prefer the webcam stream to be in a window instead viewing a web page
The MIT License (MIT)
Copyright (c) 2016 Lochie Ashcroft
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