DIY Pi Buggy

The motivation behind this project came from a robotics and engineering club that I've been going to. I've been saving my money and building up an understanding of raspberry pi and electronics. The reason I chose this project was to get used to using motors and controlling different speeds. I am self taught as I am home schooled and my mum and dad (who are my teachers) don't understand how to use the raspberry pi!

The project is a movable/programmable buggy that can move forwards, backwards, left and right.

The fun part of this project was adding a camera to it and filming the movements that it was making and crashing it into things! I also loved experimenting with different motor drivers and components. I chose the explorer hat because it was easy to use and program.

• Raspberry Pi
• The Explorer Hat Pro
• 2 x Motors (Make sure that they don’t take more than 220ma from the pi)
• 2 x Wheels that fit the motors
• Caster Wheel
• Premade Chassis / Ply Wood (to make one, or have one laser cut)
• Power Bank with an output of 2,000ma (or some way of powering the pi, Explorer Hat and the Motors)
• Cable Ties (Bunnings are good for this one)
• Jumper Wires (About 5)
• Soldering Iron and Solder

Directions

Note: Skip step 1 and 4 if using premade chassis

1. First take the ply wood and cut out a rectangle measuring 22 (L) x 12 (W)cm and mount the castor wheel on the front of the wood.
2. Take the motors and solder two jumper wires to the pads on the motors.
3. Mount the two motors to the chassis using cable ties. Add the Wheels.
4. Drill two holes for the jumper wires to go through.
5. Mount the power bank on the chassis wherever you like – I mounted mine on the underside of the chassis in front of the motors using cable ties.

Installing the Pi and the Hat

1. Disconnect all the cables from the Pi and attach the Explorer HAT
2. Attach the Pi and HAT to the chassis
3. Insert jumper leads (from the two motors) into the two motor ports on the Explorer Hat.

The Code

Write the following code into a Python 3 window:

import explorerhat as eh
from guizero import App, Text, Box, PushButton
from time import sleep
 
 
def backwards():
    eh.motor.one.forward(100)
    eh.motor.two.forward(100)
    sleep(1.5)
    eh.motor.one.stop()
    eh.motor.two.stop()
 
    
def forwards():
    eh.motor.one.backward(100)
    eh.motor.two.backward(100)
    sleep(1.5)
    eh.motor.one.stop()
    eh.motor.two.stop()
 
 
def right():
    eh.motor.one.forward(100)
    eh.motor.two.backward(0)
    sleep(0.5)
    eh.motor.one.stop()
    eh.motor.two.stop()    
 
 
def left():
    eh.motor.one.backward(0)
    eh.motor.two.forward(100)
    sleep(0.5)
    eh.motor.one.stop()
    eh.motor.two.stop()
app = App(title="Buggy Controler", height=125, width=245, layout="grid")
box = Box(app, layout="grid", grid=[5,5])
forward = PushButton(box, forwards, text="  Forward  ", grid=[1,0])
reverse = PushButton(box, backwards, text="  Backwards  ", grid=[1,2])
right = PushButton(box, right, text="  right  ", grid=[2,1])
left = PushButton(box, left, text="  left  ", grid=[0,1])
app.display()

The Finished Buggy

Now that it's all assembled and coded, you can use VNC to remotely control the buggy! Cool!