FoxyPI - motion/non-motion pulse induction metal detector, built on the Arduino Nano 3.0, with audiovisual indication, setting parameters via the menu, automatic or manual ground balancing.
Hex-file for Arduino Nano 3.0 (version 3.3 from 04/16/2019) - https://acdc.foxylab.com/sites/default/files/FoxyPIv3_3.ino.eightanaloginputs.hex
Elf-file for Arduino Nano 3.0 (version 3.3 from 04/16/2019) - https://acdc.foxylab.com/sites/default/files/FoxyPIv3_3.ino.elf
The detection range of targets in the "air" test in non-motion (in a motion a little less) mode:
(the test was carried out with the batteries discharged to 1.3 V , therefore, the data are understated)
golden ring - 9 cm;
coin 5 roubles (U.S. quarter analog) - 15 cm;
HDD plate - 33 cm.