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

[BC547]

P.S This is my metal detector.

Nice build with crutch stem

The explanation of the algorithm starts with the block diagram here: http://users.telenet.be/willaert/MD/pickini/pickini_en/V4/intro.html

[biciuliux]

Hi all,

Now I'm doing my science project about his metal detector and I need help with algorithm. Maybe some of you have created algorithm and can send it to me?

I will be very thankful.

P.S This is my metal detector. Thanks F117 and people who helped

[reptooyep]

Hi there,
I've just finished my underwarter pickini detector with :
QI charger
Single 3,7v 4400mAh lithium pack
Pressurization valve
Magnetic switch
Plastic tubes rod
Aluminium harm bracket
Home-made SMD Board.

It works just fine on soil but i didn't want it to be too sensible cause i'm not sure of the salted water functionning.
The box is sealed with airplane's fuel tank sealing compound.

A big thank to Bernard for his great project, his modification for pin7 output and his advices.

[BC547]

I wish you could have added some LEDs for power On and Signal strength showing the detection level like bar graph as you are already using ADC part of the PIC you could have displayed the same as well as an optional arrangement.

One of my design goals was to keep the part count as low as possible, ideally it should be 1 chip design if there were a decent opamp inside the microcontroller.
Extra LEDs require extra I/O pins or an I/O expander eg via I2C. You can add a power-on LED directly to the 12V or 5V on the board via 2K2/1K resistor.

[UnHappy]

Hello Bernard
First of all congrats very nice design you have made. I will be trying it in few days as currently I am collecting the necessary parts. I wish you could have added some LEDs for power On and Signal strength showing the detection level like bar graph as you are already using ADC part of the PIC you could have displayed the same as well as an optional arrangement. Anyway nice project

[WM6]

The human ear is quicker to the perception of differences than the human eye.

Agree. LCDs are mostly fancy nonsense, useful for shows and exhibition, but not for real terrain searching.

[BC547]

Maybe someone try to put lcd in his metal detector

No idea what the context of your question is ?
In general there are many detectors with an LCD next to an audio signal. Mainly induction balance detectors where you can process a lot more information, like amplitude, phase shift, etc... that can be displayed.
With this simple PI design, you just dig whenever you get a solid and repeatable beep. It has no discrimination and is therefore the tool of choice for militaria, beach and all metal detection.
My XP GoldMax Power doesn't have an LCD either. The human ear is quicker to the perception of differences than the human eye.

[biciuliux]

Hi, Maybe someone try to put lcd in his metal detector?

[ripsdevala]

Really helpfull, I hope it will reduce switching noise.
thanks for the reply

[reptooyep]

Hi,
You're right, it's been a while but i'm a father for the 2nd time since 4 month.
The 4700 cap should replace the c2 before the 5v reg.
But you can put it wherever you want between 12v and GND.
Those dc to dc boards are pretty convenient and cheap. Viva China !!!
The DIY paradise

[ripsdevala]

Hi,
I've experimented inductive charger with a collpits oscillator and a 10 turns coil few month ago without good results.
I bought those QI charger on ebay for few $.
My setup is :
QI charger + charging circuit board, 4400mah liion 3,7v, dc to dc converter board.
I replace the input capacitor by a 4700uF cause the 12v output of the dc to dc board is too noisy.
Now, it's sealed for a long time.
Results in salt water will come this summer.i'll test it in the forest to find some beer caps ��

Good day repto, its been a while,
Im interesting with 4700uf caps trick, i use standart dc to dc converter to make 12v, what caps should i change, can i have a photo.

Thanks

[reptooyep]

I forgot to tell you about a problem with induction charger :
The emmiter and receiver coils must me at 3mm maximum.
I put an epoxy layer on my receiver coil and i must take off the transmitter case to make it work.
This wilm be a problem if using your detecting coil. The housing is too thick to work properly.

[reptooyep]

Good idea but not simple to manage. The emmiter charging coil must be the same size, you'll have to diy.
The blue thing is a wheel valve to pressurise the case.

[BC547]

Interesting battery / charger configuration.

My ultimate goal would be to re-use the search coil as charging receiver coil. Just flip a switch to connect the coil to the charger unit and place it on top of the base plate overnight ...

Correct me if I'm wrong:
On your picture, I can further identify the sliding magnet on this plastic side rail that switches the detector on/off. Nice !

What is the blue handle-like thing ?

Do you have a headphone connection ?

[reptooyep]

Hi,
I've experimented inductive charger with a collpits oscillator and a 10 turns coil few month ago without good results.
I bought those QI charger on ebay for few $.
My setup is :
QI charger + charging circuit board, 4400mah liion 3,7v, dc to dc converter board.
I replace the input capacitor by a 4700uF cause the 12v output of the dc to dc board is too noisy.
Now, it's sealed for a long time.
Results in salt water will come this summer.i'll test it in the forest to find some beer caps ��