Starting with an off-the-shelf Nike + iPod transmitter [top], I removed and modified the circuit board [second from top]. I constructed a receiver from an Arduino Pro Mini microcontroller and a Nordic radio chip [second from bottom]. Then I repackaged the transmitter to make it easy to replace its battery and switch it on and off [bottom].
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.