Since you can easily destroy hardware using this adapter, we really recommend it only for experts and people who fully understand what they’re getting into by pushing arbitrary voltages into their fancy computers! Use a multimeter to probe the magjack pins to verify you’ve got the right voltages before plugging in into your computer.
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.