PICKINI V4 - an easy to build, self adjusting PI detector

[jeep6789]

Most importantly, I want to know its detection range, whether it can achieve the performance of general pulse detectors, such as Felezjoopi, and stability, whether it is suitable for large coils,

[BC547]

Does the pulse width change more than the pulse amplitude

If the pulse slope is exactly 45 degrees and depending on where you sample the voltage, ...no/yes.

When detecting the pulse amplitude, we have a time-lapse sampling pulse as a reference, but when detecting the width, what do we use as a reference, should we also have a sampling pulse? How do you track this pulse that's changing in width

The microcontroller keeps track of all samples in a slow running average value. Any samples that are different from this average = reference will trigger the target sound.
Slow changing ground influence is averaged out. This technique is also explained in the software examples in the book "Inside the metal detector"

[jeep6789]

When detecting the pulse amplitude, we have a time-lapse sampling pulse as a reference, but when detecting the width, what do we use as a reference, should we also have a sampling pulse? How do you track this pulse that's changing in width

[jeep6789]

' Does the pulse width change more than the pulse amplitude

[BC547]

What is the detection effect?

When a target is under the coil, the pulse width increases.
The pulse width is measured with a high-resolution timer (32 MHz).

[jeep6789]

What is the detection effect?

[BC547]

PCB looks OK.
Check the DC values on the pins of the opamp and the PIC controller ( with coil connected ) as described here:

http://users.telenet.be/willaert/MD/pickini/pickini_en/V4/electronics.html

Hex file Pickini 4.1:

http://users.telenet.be/willaert/MD/pickini/software/v4/Pickini4.1.hex

[sbalio1]

Friend i ask if my pcb havent error
. And hex file whitch hex did you using. What about diameter of wire

[BC547]

I made this pinpointer but coil dident works i there is no sens

? Do you mean : I don't know how to make a coil ?
There is plenty of information to be found on this forum or in the "Coils" specific part.
Here is my 2 cts on coils for Pickini:

http://users.telenet.be/willaert/MD/pickini/pickini_en/V3/coil.html

And of course there is the excellent coil calculator by Qiaozhi:

https://www.geotech1.com/forums/showthread.php?17909-Coil-Calculator

If you just want to test the detector, you can hook up a simple bundle coil - diameter 20 cm / 26 turns.

And take it outside for testing.

[sbalio1]

hi i made like this pcb https://www14.0zz0.com/2022/04/11/01/507527140.jpg
https://www3.0zz0.com/2022/04/11/01/440374246.jpg but there is no sense coil

[sbalio1]

I just buying pic16f1824 . I made this pinpointer but coil dident works i there is no sens . Iwell put my pcb.

[jeep6789]

What are the advantages of detecting the width of counterattack pulse compared with its amplitude? Then where does the width of counterattack pulse start and end? Could you please give me a schematic diagram

[sbalio1]

Hi to all freinds tell me pleade i make pikini v4 it works but coil diden works . Why.

[BC547]

The pinpoint button switches from motion to non-motion.
This means that new samples are no longer added to the slow running average reference value.
You place the coil away from the target and press the button there. The running average = reference is ground without metal target.
Keep the button pressed and move it over the target. There will be a difference between the stable reference and the target value -> target sound.
You can keep the coil over the target with the button pressed and the signal will not null out.
This is how the pin-point function is implemented. It allows you to hover over a target.
It has often helped me in determining the size of a target ( talking about bigger sizes here = WW1 artillery UXO)
You could also try to reduce the sensitivity before pinpointing.

[Metalfree]

Dear f117
I tried the MD on the beach, excellent stability even with high mineralization perfect functioning.
On the other hand, the PicPoint does not work as it should, in practice once it has detected the metal it always sounds
even lifting the MD, should it work as non-motion I guess like other MD do?
Using the latest version of the software
Greetings