Bypass capacitors – the components designers put in to help with dips in power due to switching digital circuits (and the components the factory tries to get rid of).
John Dunn writes on EDN about all the capacitive factors in a circuit, that they are non-ideal (they have resistance & inductance also making for resonant circuits) and what all those resonances might do if one appears at your clock frequency.
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.