Arduino metal detector?

[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]

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)).

[6666]

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

[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]

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

[DonCaffeDelaSkobalj]

input currents compensation and temperature drift also.

[FoxyLab]

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

[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.

[Vadim18]

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

[FoxyLab]

[ATTACH]51022[/ATTACH]

Tell us the purpose of this circuit.

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

[DonCaffeDelaSkobalj]

[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.

[Rodelio]

At last i build this MD. It work nice but i have som trouble thr first time.
I read carefully in the site of foxilab and i realice that it need a double power supply. so i have to make som changes on the dising of PCB.
Because it wont work. zero signal in the output of LM358.
Here adjunt a .lay file for editing... see you.FOXY MD changes to do.rar

[Rodelio]

Hi. I taked a SprintLayout file already posted here in this thread and do it some touch... FOXY MD.rarAs soon i get it working, I will like to do a very samall PCB with SMD components using Arduio Nano...

[FoxyLab]

FoxyPi hex file working in a little island in center of america[ATTACH]50930[/ATTACH]
I don,t know how to upload videos, so i post a screenshot from my samsung cellphone.. [ATTACH]50931[/ATTACH]

Hola, Rodelio! Excellent!