FoxyPI - Arduino Nano metal detector

One of the new finds with FoxyPI MD (before and after electrolytic cleaning):

Metal with magnetic properties, the shape is close to a hexagon with a side length of about 8 mm, the edges are uneven, and there is an asymmetrical hole in the middle.

Old handmade "iron" button?

Examples of signal curves in test mode:

1 - without a target, 2, 3, 4 - when approaching a massive target:

Minor update ( version 3.8 ) is ready (FoxyPIv3_8.ino.eightanaloginputs.hex):

improved display of signal curves in test mode (through earlier reading of preset settings, including contrast).

One of the new finds in the garden with a metal detector FoxyPI (after electrolytic cleaning):

The thickness of the metal (5.5 mm) and the characteristic shape are an echo of WWII. I calculated the inner diameter, which turned out to be approximately 4.3 cm.

Influence of the value of the GUARD parameter on the detection range of the golden ring (L):

GUARD L, cm

500 ---> 12

750 ---> 10

1000 ---> 8

1500 ---> 7

It is possible to decrease it even below 500, but in this case false positives may appear.

An interesting find in the garden with FoxyPI - an unusual chrome detail (photo after electrolytic cleaning):

Errors that may occur during zeroing:

ERR 01 - the saturation section was not found in the signal:
     * coil break
     * no pulse generation
     * the signal during zeroing is so strong that the saturation region is shifted beyond the registration window

ERR 02:
     * the signal during zeroing is strong enough so that the saturation region lasts until the end of the registration window

FoxyPI firmware v3.7:

FoxyPIv3_7.ino.eightanaloginputs.hex

What's new in version 3.7:

* small code optimization was performed to increase the stability of the metal detector
+ beep indication for errors ERR 01 and ERR 02 added

Service menu in firmware v3.6:

FoxyPI firmware v3.6:

FoxyPIv3_6.ino.eightanaloginputs.hex

What's new in version 3.6:

+ added the ability to configure the guard interval using the GUARD item of the service menu;

+ added auto-tuning of levels 1 and 2 of the audiovisual indication in static mode;

+ integrated test mode (to activate, after switching on, hold the control button until the graph of the signal curve appears)