Inverted pendulums can be a pretty cool testbed for controls stuff. They’re relatively simple, but very non-linear systems, and there are a lot of approaches to swinging up and stabilizing the pendulum. The Furuta pendulum style of machine is particularly interesting, I think. If built right, they can be very small but have unlimited travel, unlike the car-pole style of inverted pendulum, which eventually runs out of track for the cart. Although the full non-linear equations of motion are much more gnarly, for small motions the behavior is largely the same, so it’s not actually any harder to stabilize.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.