Arduino metal detector?

[FoxyLab]

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.

[DonCaffeDelaSkobalj]

[FoxyLab]

[ATTACH]51022[/ATTACH]

Tell us the purpose of this circuit.

P.S. The metal detector analyzes the signal of one polarity only.

[Vadim18]

I gues this circuit provide constant load for positive voltage. For shortening opamp settling time after tx pulse?

[FoxyLab]

I gues this circuit provide constant load for positive voltage. For shortening opamp settling time after tx pulse?

In this case, this addition is not very relevant - the saturation section of the operational amplifier/ADC is longer than setting time.

[FoxyLab]

One of the new garden finds from FoxyPI -an unidentified non-magnetic "light" metal part:

[DonCaffeDelaSkobalj]

input currents compensation and temperature drift also.

[6666]

Found this in my archive not sure where I got it, or if it works

[FoxyLab]

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.

[6666]

You have some interesting things in your garden, hope there are none live

[FoxyLab]

You have some interesting things in your garden, hope there are none live

15 km from here is the Sozh river, along which the first line of defense of the Eastern Wall passed here. In 1943, very heavy battles took place here, in which most of the Soviet 11 Army died (my little research on this topic - blog.foxylab.com (in russian)).

[Vadim18]

15 km from here is the Sozh river, along which the first line of defense of the Eastern Wall passed here. In 1943, very heavy battles took place here, in which most of the Soviet 11 Army died (my little research on this topic - blog.foxylab.com (in russian)).

You not so lucky - about two monts ago i visually found live WWII bombshell, while driving a bicycle on the road between railroad and fields.
Size was like a 1.5 liters bottle of mineral water. I called police, and have some fun

[FoxyLab]

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).

[FoxyLab]

Examples of signal curves in test mode:
1 - without a target, 2, 3, 4 - when approaching a massive target:

[6666]

Examples of signal curves in test mode:
1 - without a target, 2, 3, 4 - when approaching a massive target:

looks good