Tombstone - Micro:bit robot

The inspiration for this project was a TV series called Battlebots. We saw 2 seasons on Netflix. It was about robots battling each other in an arena. My favorite robot was called Tombstone.

This is the robot we built. It uses some Micro:bit components, some motors and Lego Technic pieces.  It is powered with a USB power bank. The chassis is made out of cardboard and the components are attached with zip ties and blue tag

This project requires motors to move the robot and to move the blade at the front. As you can see in the photo we are using 1 Lego motor to move the Lego Technic that controls the blade and 2 non-Lego motors that move the robot. We also added a swivel castor wheel for support

Making the robot we discovered that can't connect the motors directly to the pins on the Micro:bit because you can fry the Micro:bit. So you need to use a motor shield. There are many available but we are using this one from Dfrobot. It is called the Dfrobot Micro:bit expansion board. This one allows you to connect up to 4 motors (M1 to M4 in the photo). You connect the power to the shield and then the Micro:bit slips into a slot as you can see in this photo

To move the blade we created a mechanism with Lego Technic. It includes a chain to transmit the rotational movement of the motor from the center of the vehicle to the blade which has to be at the front. We are using 2 gears: a big one and a small one. By having he smaller at the front we make the blade spin faster.

We wanted to control the robot remotely with a second Micro:bit so we used the the "radio" function. You have to set both Micro:bits in the same radio group. This is the code of the remote control. It is just sending strings like "right", "left", "ahead" ...

The code in the Micro:bit on the Tombstone is moving the motors to change direction accordingly. Motors 1 and 4 control the wheels and motor 2 moves the blade all the time

We had a lot of fun smashing things. We also did this video about Tombstone kicking Lego minifigs around. I hope you like the video