Arduino based pulse induction metal detector

Looks good. Think I saw you posting this on the Geotech forum.

I do need to figure out how to use a translator for your web site. I looked through it and seems lots of good info from the pictures and diagrams. Just need to read the text.
Got it - Chrome translates.
 
Think I saw you posting this on the Geotech forum.
Yes, I replied you there.

I made a software emulation of the integrator and the filter, which provided the desired stability and sensitivity with motion mode.

"Air" and "underground" tests of the new version 3.3 -
 
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).
 
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 µs, 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 ;)
 
The first result of the first garden search with FoxyPI v3.3:
fox_ok.png

FoxyPI_v3_3_tgts_190421.jpg
 
You must be detecting in my yard. lol
I find lots of nails bent like that.
;) I made many different finds with version 2 of FoxyPI (including, of course, many-many nails:laughing:).
This is the first find in the first real search with version 3.3. Ahead of a lot of interesting:yes:
 
This is a very nice project. I plan on making a coin tumbler. Thinking about using an arduino but a simple 555 timer and pot would be simpler. Nice to see combining two hobbies into one. Keep up the good work.

:thumbsup:
 
This is a very nice project. I plan on making a coin tumbler. Thinking about using an arduino but a simple 555 timer and pot would be simpler. Nice to see combining two hobbies into one. Keep up the good work.

:thumbsup:

Thanks
fox_ok.png

My first homemade metal detector was also analog, but digital MD FoxyPI turned out to be more convenient and sensitive.
 
Awesome project! Designing and building your own machine is super impressive [emoji106][emoji846] Thank you for sharing.
 
I built a model of the entire power part of my metal detector for LTspice XVII:
FoxyPI_v3_tran.asc

You can play with the parameters and watch, for example, the voltage on the search coil (1), on the opamp input (2), the current in the coil (3):
FoxyPI_v3_tran.png
 
Last edited:
The final firmware version 3.4 is ready - FoxyPIv3_4.ino.eightanaloginputs.hex
What's new:
  • MOSFET overheating is excluded
  • increased stability
  • added auto-tuning interval between ADC samples
  • added display of the signal curve after auto-balancing
FoxyPI_v3_static_searching.png

And here is how the interference from a nearby LCD TV appears:
FoxyPI_v3_LCD_noise.png
 
Back
Top Bottom