The Bigtrak was a programmable electric six-wheeled robot popular in the 80s. It used a keypad on top to allow the user to enter instructions, which it would then carry out sequentially.
In 2010 it was relaunched. I had one of these lying around from years ago as well as a spare Arduino Mega so I decided to see if I could hack it.
The full how-to guides I wrote for this project are available on my blog Micropi here:
- https://micropi.wordpress.com/2018/09/23/bigtrak-with-an-arduino-part-1/
- https://micropi.wordpress.com/2019/04/09/bigtrak-with-an-arduino-part-2-remote-control-with-an-esp8266/
Firstly I took out all of the internal circuit boards and found the connectors for the two motors. I then wired them to a cheap L298N-based motor driver board which I in turn connected to the Arduino Mega. To power it all I used a battery pack of 5 AA batteries.
Once I got the motors working under the Arduino’s control I decided to add remote control to it. To do this I used an ESP8266 WiFi chip. I used WiFi because it has a good enough range for me and is already compatible with many devices such as laptops, phones and tablets.
To control the robot you sent HTTP requests with the speed of the two motors and whether they should be in reverse as four arguments in the URL. I wrote a Python script using the requests library combined with a Tkinter user interface to serve as a remote control.
On the Arduino side I wrote code in order to parse the HTTP requests for the needed arguments using the Arduino language, which is based on C/C++. The ESP8266 is set to AP mode, which means that it broadcasts its own WiFi access point for devices to connect to. This means that a WiFi router isn’t needed, making it portable.
The code is all on GitHub here: https://github.com/brychanthomas/Micropi-Bigtrak
At the moment I haven’t connected the ‘photon blaster’ LED, the speaker or the keypad to the Arduino although that could be a future improvement.
Brychan Thomas' projects 