Not actually elusive*, as this happens on a regular basis inside your phone, computer and nearly everything else with a clock or carrier, but I thought it would look cool as a GIF, so I made one.
This is a PLL achieving lock in an 8x multiplier circuit after a frequency shift. I could watch this all day.
*- can actually be elusive if you’re not familiar with loop filters.
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.