Arduino metal detector?

[waltr]

Nice work FoxLab. Nice simple PI detector.

Samples sums integration

I am guessing this is a software implementation of the op-amp RC integrator found in most PI detector circuits.

I have written code to do this op-amp integrator functionality and it does increase sensitivity and decrease noise.

[FoxyLab]

Thanks for the update Foxylab, what is the frequency of your main electricity supply in your country 50/60 Hz, does it cause your detector any problem ?

50 Hz.
Samples sums integration successfully solves this problem

[6666]

Thanks for the update Foxylab, what is the frequency of your main electricity supply in your country 50/60 Hz, does it cause your detector any problem ?

[FoxyLab]

With the addition of the autotune of the initial delay and the duration of the analyzed signal, the development of FoxyPI version 3.3 can be considered complete.

Summary:
pulse metal detector operating in non-motion and motion modes;
setting parameters through the menu, audiovisual indication;
The default parameters are a pulse width of 150 us, a repetition rate of 80 pulses per second.

Main electronic components:
Arduino Nano 3.0, LM358N, MOSFET.

The detection range of targets in the "air" test in non-motion (in a notion 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 rubles - 15 cm
HDD plate - 33 cm
Something like this

[Hammerhead]

Didn't had user Hammerhead from Egypt also built some Arduino MD?

If he is still around just a tip:
Nokta Makro Anfibio - Full Water Proof - perfect for Beach and Diving![ATTACH]46007[/ATTACH][ATTACH]46008[/ATTACH][ATTACH]46009[/ATTACH]
Import from Turkey via Lebanon to Cyprus - by Speed-Boat! *laugh*

Hello my friend, I am now working on the Pirate Metal detectorUnderwater

[Funfinder]

Didn't had user Hammerhead from Egypt also built some Arduino MD?

If he is still around just a tip:
Nokta Makro Anfibio - Full Water Proof - perfect for Beach and Diving!
Import from Turkey via Lebanon to Cyprus - by Speed-Boat! *laugh*

[FoxyLab]

You have super slow motion detector

An increase in the pulse repetition rate up to 80 pps markedly increased the detector "responsiveness".

[FoxyLab]

Added the ability to work the metal detector in static (non-motion) mode:

Switching between dynamic (default) and static modes - by long pressing the button.
Static mode can be used for pinpointing, as well as the main search mode (stability is sufficient).

[dbanner]

[FoxyLab]

Very good ... We appreciate sharing with us your work. Thanks.

Very thank for the support!!!

You have super slow motion detector

It is necessary to choose the optimal coefficients of the integrator and the filter

Why is there always high tone after low tone? What is the use of that except for being extremely annoying?
Is it supposed to help in pinpointing the target? If so, may I suggest you make it a little shorter in duration

Low Tone - movement of the coil to the target (signal increases) ; High Tone - movement of the coil from the target (signal decreases) (Yes, is good for pinpointing - my little "know-how" , but tone length required tuning)

[dbanner]

Very good. You have super slow motion detector. Why is there always high tone after low tone? What is the use of that except for being extremely annoying?
Is it supposed to help in pinpointing the target? If so, may I suggest you make it a little shorter in duration. Or maybe you plan for ferrous/non ferrous in future with low and high tone?
We appreciate sharing with us your work. Thanks.

[FoxyLab]

I read your web site (used Chrome translator) and very nice project and write up.
Also read your explanation of discrimination with Neural nets. Very interesting.
Have you been able to add this neural net into your detector?

Thanks!!!
Version 4 is canceled. Everything turned out to be simpler - I made a software emulation of the integrator and the filter, which provided the desired stability and sensitivity.
"Air" and "underground" tests of the new version 3.3 -

(for discharged batteries and at approximately matched coefficients it turned out not so bad).

Studies with the neural network I did for the static version of the metal detector.
I will try add discrimination to current version MD with motion mode.

[waltr]

Version 4 underway. Static mode (and 30 pps) will be back , but with ADC use and integration (unlike comparator use in version 2) and better stability.

I read your web site (used Chrome translator) and very nice project and write up.
Also read your explanation of discrimination with Neural nets. Very interesting.
Have you been able to add this neural net into your detector?

[FoxyLab]

Version 4 underway. Static mode (and 30 pps) will be back , but with ADC use and integration (unlike comparator use in version 2) and better stability.

[FoxyLab]

PULSE RATE - pulse repetition rate (10/20/30/40 pps)

Foxylab I am curious for your reason why you choose a very low pulse rate ?

I compare the differences in the curves for two adjacent pulses. If you take the frequency higher, the difference will be less noticeable (worsening, if I may say so, the signal-to-noise ratio). For coil speeds up to a meter per second, sensitivity at such a low frequency is quite acceptable.