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

[kosacid]

I have tried a few coils on this but I don't seem to be getting good depth only on large stuff I'm using a 8" coil, also any hints on making it more sensitive maybe a bit chatter, I can compile the c so is there a section I can try to make it sensitive, or make a coil that is better for this detector, I don't seem to get the results that others are getting, also dampening will that help ?

[BC547]

Marty,

Pickini V2 is very old. The 100k pot is to set up the DC offset of the opamp and should be adjusted to 8 V.

With Pickini V4, this is adjusted automatically at startup.
Why would you like to build V2 ?

Regards,
- Bernard

[MartyJ1963]

Hiya Bernard,,,,Can you tell me what R21 is for on your new Revision - Pickini 2?,,,the 100k pot? Thanks. Regards,,,Marty

[BC547]

PICKINI V4 SHOP

You can now buy 2 items in the Pickini shop:

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

A programmed microcontroller:




A semi-kit consisting of PCB + all semiconductors, including the programmed microcontroller




This way, the microcontroller should be available to everyone.

- Bernard

[BC547]

It is Basetech 1310189. When you google it, you will find it on different websites
Not sure if "Basetech" is even the name of the manufacturer.
I bought it in Belgium at Conrad -- also available in Germany: https://www.conrad.de/de/werkzeugkas...e-1310189.html

http://www.produktinfo.conrad.com/datenblaetter/1300000-1399999/001310189-in-01-ml-BASETECH_WASSERDICHTE__de_en_fr_nl_it_pl.pdf

[nonkapo]

Dear Bernard,
Do you mind sharing info on the exact box model you use(basetech) as when going to the web site I get totally lost. Did not see info about the size either, probably cause the boxes are designed for particular phone/device. Thanks.

[Goaty]

Thanks for the info Bernard.

The circuit diagram is just what I needed - When I get the piezo buzzers I ordered I will check their current draw and find a suitable transistor to handle it.
I will be getting 95dB piezos and hope these will be loud enough as I have to use earplugs when swimming/surfing nowadays due to chronic 'surfers ear'. Not sure what the medical term for this is but it is boney growths in the ear canals which are now almost totally blocked. I guess scuba divers could also suffer from this, especially in cold water.

I have been experimenting with getting sound out of my PVC pipe waterproof detector enclosure using a 105dB driver from a security alarm piezo 'screamer'. It is very loud but is two tone which is not really suitable for detecting. I have simply bonded the piezo disk onto the inside of the 2" PVC pipe cap using epoxy and the results seem promising.

BTW, I have had a hand in building 4 Pickinis to date. Two for myself (1 terrestrial and one diving) and another two with friends as their introduction to metal detectors. All have worked perfectly first up which is a testament to your design, so thank you.

Goaty

[BC547]

Pin 7 of the PIC is a static detection pin: high (5V) = target / low (0V) = no target.
You can attach a buzzer/beeper with an extra transistor to the 12 V rail or in an identical way to the 5V rail.
The NPN transistor is not critical.
The resistor value can be 2K2 ... 10K (or more).

Something like this:



I connected a beeper once like this inside the housing for a dive version.
But when testing it in the 15 m dive tank, it kept beeping from the surface to the bottom because the tank itself is made of steel.
This was so annoying for other divers in the tank - it was really loud ! - that I removed it again and replaced with a cheap but bright flashlight that is pointed towards the coil through the transparent housing.
It lights up when a target is detected. Connected in the same way as attached image.

See also http://www.geotech1.com/forums/showt...708#post229708

[Goaty]

Bernt,
you can connect a LED directly to pin 7 of the controller. This was added as described in post #291.
This is a simple on/off detection indicator. You can attach an extra transistor here to drive more powerful LEDs - or a powerful buzzer ( to be heard underwater, even without headphones . When you attach the buzzer to the housing, the noise can be heard underwater).
A single hi-bright LED can be connected directly to the pin via a 470E resistor.

- Bernard

Hi Bernard
I would appreciate if you could provide further details on this - ie driver transistor circuit and piezo buzzer type.
I am in the process of modifying my snorkelling Pickini to add audio as I am finding the LED on the housing difficult to watch as well as swinging the coil underwater.
Thanks
Goaty

[gurdal]

F117 thank you so much

[kosacid]

i have built 2 so far they work good next thing i need to do is to print a box, good work Bernard, going to swap out the pic16f1824 for arduino and add a lcd just for fun

[BC547]

@gurdal:

The LM318 is upside down.
Have a look at the pictures here:

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

Also: pin 8 and 9 of the PCI16F1824 must be shorted !

There were some layouts around that had both these mistakes.
Therefore: please look at my homepage for reference.

[gurdal]

[Goaty]

Thanks Bernard - most appreciated!

[BC547]

@ Goaty:

These are my gerber files:

http://users.telenet.be/willaert/MD/pickini/pickini_en/V4/gerber.zip