Based on Raspberry Pi Pico board, this metal detector is included in pulse induction metal detectors category, with well known advantages and disadvantages. RPi Pico generate 3,3v amplitude pulses at one of GPIO pins. This pulses are amplified and applied to a MOSFET device that had the searching coil in series with drain. The pulse will produce a magnetic field generated by the searching coil, and becose of eddy currents, the target will produce a very low corresponding voltage...