PiBot: An Educational Robot

Every hardware hacker builds an educational kit at some point. This is my first attempt -- it's still a little rough around the edges. I chose a Pi Pico as the core microcontroller, so students could work with Python. The on-board motor controllers are sufficient for small N20 motors, and there are expansion ports to connect a wide variety of sensors. Unlike a lot of kits, it uses standard JST headers, I'm not trying to create a walled garden here!

The main board is compact, and easy to work with.

Populated Board

Not all of the motor controllers need to be connected -- this board can be used for both differential-drive robots (two motors), and omnidirectional robots (4 motors and Mechanum wheels).

JST connectors are provided for sensors, motors, power, and expansion. There also an auxiliary 12V power output.

Cable management can be a pain with robots, so I kept it clean.

Assembled Robot

The robot can be assembles using a variety of rigid cases. Wood, plastic, and metal are all appropriate. The board can be fixed in place with standard M3 bolts or hex spacers.

Still pretty clean! A standard 18650 lithium cell supplies power.

Assembled Robot

The assembled robot is intended to use laser time-of-flight sensors for autonomous navigation. Ultrasonic sensors can be used too, but the laser ToF ones are really cool and about the same price.

For orientation, we use a gyroscope. These are quite accurate for measuring rotation via dead-reckoning, especially when corrected with measurements from the laser ToF sensors. A magnetic compass is used for absolute direction.

The completed robot is durable, and easy to expand and maintain.

Current Status

It's a prototype. A pretty good one perhaps, but it needs more work on the software and curriculum side. I wrote up some motion libraries, and they work alright, but it needs a lot more polish before this can become a real product. A half baked educational product is just confusing to students and achieves nothing!

The major unfair advantages I'm aiming for here are cost, simplicity, flexibility, and easy maintenance. Some schools or universities import robot kits from overseas at great expense -- then the moment a connector breaks, it's trash and they have to order new parts. These new parts are manufactured in Asia, shipped to the USA, then shipped back to Asia. It's just silly. We know how to make things here!

I will return to this someday and finish it. For now I'm working on other things though!