Metal detector with arduino

Projects General Guidance
1

I am wondering how to make a metal detector with arduino.
Does anyone have a tutorial that would be good for some one with no metal detecting knowledge?

I am planing to start with something simple and then gradually add features.

Thanks

I found a lot of conflicting tutorials that many said did not work.

2
3

Um.. I can't read in that language.....

4

Ok, I translated it to English.
The schematic does not make much sense.
How does it detect metal with only one coil?

5

A translated bit from the article says:

The operation of the circuit is as follows. A square wave, generated by Arduino pin A4, goes to the LR high-pass filter. Due to this, very short peaks (about 0.5 microseconds) are generated each time by the coil, corresponding to as many pulses. The pulse length of the peaks thus generated is proportional to the inductance of the coil. So, with the help of the peaks of these pulses, we can in principle measure the inductance of the coil, however the peaks are too short.

Therefore, to solve this problem, a capacitor is used which is charged by the rising pulse or peak. And a few pulses are enough to charge the capacitor to the point where its voltage can be read from the analog pin A5 of the Arduino, thanks to the Analog-Digital Converter (ADC) with which the Arduino is equipped. After the voltage has been read, the capacitor is quickly discharged via “software”, setting pin A5 as the output and setting it to “low”.

Inductance changes, due to the coupling of the coil with the metal being detected, changes the sizes of the pulses that are integrated in the capacitor and read by the ADC. The Arduino empties the capacitor on A5, switches pinMode, sends a number of pulses on A4, and checks the integration on A5. Pretty cool if it works.

6

Oh..... that is the problem with the internet.
I would prefer something more simple?
That is more likely to work?

7

Does anyone have a suggestion for something that will probably work?

8

I'm not saying that scheme doesn't work. Just that I've not tested it.

9

I might follow along with that one and see how it works.
Found this:https://www.instructables.com/DIY-Simple-Sensitive-Arduino-Metal-Detector/
and:
https://www.instructables.com/DIY-Very-Simple-Arduino-Metal-Detector/
One coil!!

10

Hi, @anon92864395
This YouTube channel has some interesting detectors.

And some instructions.

Tom... :grinning: :+1: :coffee: :australia:

11

Try searching for beginner-friendly tutorials on websites like Arduino Project Hub or YouTube. Look for well-reviewed tutorials and consider starting with a simple design before adding more advanced features so that you gain confidence. It's common to find conflicting information online, so choose a tutorial with positive feedback to increase your chances of success. Or use AI softwares for this research.
Wish you good luck for your project.

12

Thanks!
It is actually made by the same person that made the detectors that I Shared the links!
Thanks!

13

What types of metal detectors exist?
What type should i start with?
Thanks

14

I need some wire for coils....
Anything recommend from amazon?

15

How many ChatGPT copy/pastes are enough?

16

Should I flag it???

17

The user has only done two chat replies. I should have noted chatgpt reply-posts are from a number of users.

18

One also contains a spam:

19

Ok.
I have decided to try and do this with a Pico….
I will try both VLF(2 coils. Transmit coil and receive coil) and PI(Pulse induction. One coil.)
I also am looking into motion and non motion things(no idea now).
I need to get wire and op amps.
Any recommendations for those?