This is a magnetic loop controller board designed by Loftur TF3LJ and VE2LJX. This PCB was designed by 9A3GOS (me) and assembled by two assembly factories. Each factory made 5 boards (minimum order quantity).
There is one via under the stepper driver which could be a little bigger, but I was driving 2 amps to a stepper motor without an issue.
Original design and documentation: https://sites.google.com/site/lofturj/to-automatically-tune-a-magnetic-loop-antenna
You can upload a compiled hex file to a teensy microcontroller or use Arduino environment to modify it and compile it yourself.Read more “Magnetic loop controller PCB – design by Loftur E. Jónasson – TF3LJ / VE2LJX”