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

[F117]

You can find all design info here:
http://www.willaert.world/MD/pickini_en/V4/intro.html

[sbalio1]

There is a problem, forum members, with this device. The problem is that the sensitivity begins to decrease gradually on its own, even though the battery is still fully charged. Does anyone here explain the problem to us?

[sbalio1]

I have made this device four times, but I have the same problem. The sensitivity starts to decrease on its own. Is it possible that there is a problem with a file? hex

[kt315]

• hello amigo
  
  it's not mine choice ) i deeply sure recommend to do just that had been released in 100s++ pieces. this is Main Rule. if to do crude project then you have to be expert in electronics and in the code programming.
  so buy a pcb or kit from anybody and you will get working detector. or you just waste your time. while certainly you get the experience in electronics anyway ))
  
  pleasure

[sbalio1]

HI KT315 I WAS MAKING DETECTOR SCANEER . THANKS

[Reedick]

Hi . I say happy new year to all friends here. 2025

[useus]

I finally programmed the pic with pickit 3, I turned on the metal detector but I have a problem, the detection works but I have a loud and continuous beep that lasts about a second. what do I need to check to fix it?
pickini4.2 hex
I use a buzzer connected as described on the previous page, so the sound is very loud

[F117]

useus

Test the detector outside, away from any EMI interference. Do not test it in house.
Turn down the sensitivity potmeter.
Version 4.2 is an experimental version where the sensitivity setting influences the voltage comparator slicing level.
The best version is v4.1. But you will still experience EMI noise when testing inside a building.

[useus]

useus

Test the detector outside, away from any EMI interference. Do not test it in house.
Turn down the sensitivity potmeter.
Version 4.2 is an experimental version where the sensitivity setting influences the voltage comparator slicing level.
The best version is v4.1. But you will still experience EMI noise when testing inside a building.

I tried it outdoors, in the woods, the sound it emits is not the sound of a target, it's like a preset beep that sounds for a second and stops for a second in a loop.
I will test the 4.1

[F117]

At the audio output, a pulse is generated every 2 s = confidence tick. This indicates that the detector is up and running, even when no target is detected over a long period of time. It is common with military detectors.
When you connect a 5V beeper to the audio output it will be activated every 2s.
Better would be to connect a piezo speaker instead of a 5V DC buzzer.
If you insist on using this buzzer you can connect it to pin 7 of the PIC. This is a digital output that goes high when a target is detected.
It is ON/OFF, there is no gradual increase of the "tick" from 1Hz to 1kHz as you have on the audio output.

An additional sound not mentioned here is the "coil error sound", about the same as low battery sound. But this would mean that there is something wrong with the coil/front-end and no flyback pulse is detected.
Since you mention "the detector works", this can not be the case ?

All sounds can be found here:
http://www.willaert.world/MD/pickini...technical.html

[useus]

At the audio output, a pulse is generated every 2 s = confidence tick. This indicates that the detector is up and running, even when no target is detected over a long period of time. It is common with military detectors.
When you connect a 5V beeper to the audio output it will be activated every 2s.
Better would be to connect a piezo speaker instead of a 5V DC buzzer.
If you insist on using this buzzer you can connect it to pin 7 of the PIC. This is a digital output that goes high when a target is detected.
It is ON/OFF, there is no gradual increase of the "tick" from 1Hz to 1kHz as you have on the audio output.

An additional sound not mentioned here is the "coil error sound", about the same as low battery sound. But this would mean that there is something wrong with the coil/front-end and no flyback pulse is detected.
Since you mention "the detector works", this can not be the case ?

All sounds can be found here:
http://www.willaert.world/MD/pickini...technical.html

the problem is that it is not the tick sound like on the site, I already checked, it is a long sound. could it be a problem in the circuit? for example I used irf840 instead of irf740.

Yes, the target marks it for me, it's not a coil problem since on another detector it doesn't give me problems.

I tried 4.1, same problem

https://files.fm/u/gnw8zq6m89

[F117]

Low battery detection ?
Voltage divider R8/R9 on the power supply is the battery voltage input for the PIC.
This should result in about 2.8V on pin 12.
When you disconnect R9 = 10K, the battery voltage detection will no longer work and should always be OK

[F117]

Also check all other DC voltages as described here


All voltages measured with a battery voltage of 12.0V:

• U1 - PIC16F1824
  PIN 1 : 5.0V
  PIN 2 : 2.7V
  PIN 3 : 1.2V - sensitivity potmeter
  PIN 4 : 5.0V
  PIN 5 : 4.7V
  PIN 6 : 0.1V
  PIN 7 : 0.0V
  PIN 8 : 3.7V
  PIN 9 : 3.7V
  PIN 10 : 2.7V
  PIN 11 : 0 ..5.0V - audio
  PIN 12 : 2.8V
  PIN 13 : 2.0V
  PIN 14 : 0.0V
  
  IC4 - LM318 opamp
  PIN 1 : 9.5V
  PIN 2 : 6.8V
  PIN 3 : 6.8V
  PIN 4 : 0.0V
  PIN 5 : 4.8V
  PIN 6 : 7.4V
  PIN 7 : 11.9V
  PIN 8 : 1.4V

[F117]

I had not noticed your attachment = audio file yet.
When listening to it, this sounds like the coil error sound. If you connect a headphone to the audio output, you will here a much lower intermittent tone than the one generated by the beeper.
Can you switch the detector on without the coil connected. It should give the same error sound then.
If that is the case, something is wrong with the TX side.

EDIT:
I just tested the coil error sound and this is a continuous low frequency sound.
Not intermittent like in your audio file.

After power on, you first hear the welcome sound.
Then a calibration procedure start during which you hear the 0.5 Hz confidence tick.
When calibration is finished, there is a start sound.
Then, the confidence tick - or detection sound can be heard.

Can you try with a regular headphone first.
If that is OK, connect the 5V beeper to pin 7 of the PIC.
This will not offer all tone varieties as with the headphone output, just a target detection.

[useus]

I had not noticed your attachment = audio file yet.
When listening to it, this sounds like the coil error sound. If you connect a headphone to the audio output, you will here a much lower intermittent tone than the one generated by the beeper.le tensioni sono abbastanza simili, le mie leggermente piu alte, specialmente su lm318. Si ho provato senza coil e fa lo stesso suono
Can you switch the detector on without the coil connected. It should give the same error sound then.
If that is the case, something is wrong with the TX side.

EDIT:
I just tested the coil error sound and this is a continuous low frequency sound.
Not intermittent like in your audio file.

After power on, you first here the welcome sound.
Then a calibration procedure start during which you hear the 0.5 Hz confidence tick.
When calibration is finished, there is a start sound.
Then, the confidence tick - or detection sound can be heard.

Can you try with a regular headphone first.
If that is OK, connect the 5V beeper to pin 7 of the PIC

the voltages are quite similar, mine slightly higher, especially on lm318. Yes, I tried it without coils and it makes the same sound.
with coil after calibration the detection works but it continues to make that sound
the buzzer is already connected to pin 7
even disconnecting r9 same problem

I'll try it as soon as I find some headphones