Monthly Archives: November 2016

Breadboarding the Robot Tank Electronics

With the tank chassis set up, I started working on breadboarding the electronics for the robot.  My plan was to salvage the motor driver from a dead MiniBot board, and use a WeMos D1 Mini as the microcontroller.  Here is the part list for this build:

  • Tamiya Tank Chassis w/ Gear Box and motors (see this post for details)
  • WeMos D1 Mini
  • TB6612FNG Motor Driver Board (taken from a MiniBot protosnap board)
  • Misc: a lot of jumper wire, a breadboard, and a breadboard power supply

Unlike most of my build days, this one went pretty smoothly.  The one issue that I encountered was that the MiniBot version of the TB6612FNG was a little different than the version that is more commonly sold.  Fortunately, the MiniBot kit had sample code that I was able to pick through in order to properly control the motors.

  • Snapping off the motor driver from the MiniBot board

Another issue I had was with the OTA updates (Over the Air).  The esp8266 addon package for Arduino included sample code for enabling OTA updates.  I did a few tests with the OTA code and was able to use it somewhat successfully, but I was getting some weird behaviors when I incorporated it into the tank sketch.  I think the issue might have to do with how WeMos resets itself.  It looks like one or two of the pins that I am using to control the motors get pulled high on reset.  This causes the motors to start spinning, which could cause some power draw issues.  I will need to investigate this a bit more later, but for now, I am happy with the progress and looking forward to setting the tank up so that it can be operated over WiFi.