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

[kosacid]

the coil is .5 copper 350uh I am using a 10k potentiometer that all I could find thats the only differences, and I am testing it using a big chunk of lead and it is not very sensitive to it

[Eddy71]

Try this software for you programmer:

http://picpgm.picprojects.net/software.html

[bang80]

Hello Bernard,
I bought your kit yesterday but I will try to build one myself. The PG3 PIC is old but works with the 16F1824, the question is to adjust the PIC PGM software. There are some options to check or not. I will test that. If it does not work I can always delete the PICs ...
Thank you
Ernest (Amiens, France)

[BC547]

coins rings and that is fine but bullets and lead it is just not picking them up very well

When I go field testing here in "Flanders Fields", the battlefields of WW1, they are infested with small lead shrapnel balls and bullets. I have buckets full of them and every detectorist here hates these things. Also on a IB detector, they give a very good signal. So, I obviously envy your setup and would like to trade it in for something that only detects gold and rings ;-)
What are the specifications of your coil ?

[kosacid]

ok, I have been testing this detector coins rings and that is fine but bullets and lead it is just not picking them up very well why is that? the bullet casings are fine I just can't work it out why are some metals being undetected

[BC547]

I don't know the PIC-PG3 programmer but it still seems to need a parallel port ?
It looks a little outdated at first sight but maybe someone else here can check if it still supports more recent PIC families ?
I normally use the PicKit3 programmer.

If you want to make it easy on yourself to start exploring pulse induction with temporal sampling, you can save yourself a lot of trouble and go to my shop: http://users.telenet.be/willaert/MD/...n/V4/shop.html

Regards,
- Bernard

[bang80]

Hi, I am Newbie with PIC. I have a PIC-PG3 card from OLIMEX and my program is PICpgm. How to configure the options of the program for this 16F1824 ?
Thank's for help.

[MartyJ1963]

Hi Bernard,,,,as always, thanks for info,,,always best to check. I have some of those batteries also that you bought, but never use them because I can never remember if the switch , on the battery pack, has to be 'on' or 'off' while you charge it? Does the LED on the battery pack have to illuminate red or green while charging? Sorry for the silly question,,lol. Regards ,,Marty.

[BC547]

Marty,

when you mean this charger circuit:



The answer is definitely NO for LiIon !. It is current limited but is not voltage protected. Overvoltage will kill your LiIon batteries if not worse ( risk of fire, explosion..).
For my latest build, I bought these batteries: http://www.dx.com/p/80405
It includes a mains adapter to charge the battery pack. Unfortunately: US mains plug only. I opened it up and put the small charger PCB into a Belgian style mains adapter.
It has a green/red indicator LED thattells you when the battery is fully charged.
I replaced the battery jack with a cinch connector mounted on the housing and replaced the adapter jack plug with a cinch male plug. I always use cinch connectors on my detectors to charge them.
So far I am quite pleased with the battery: it lasts a full day of searching. Wished I had more opportunity to test them over an entire day though..

Regards,
- Bernard

[MartyJ1963]

Hi Bernard,,,Thanks for info,,,,Can I use your Battery charger circuit to charge a 3x18650 cell 12v battery pack? Thanks again. Marty

[kosacid]

probe pin 6 on op amp or diodes or the coil on x10

[BC547]

Marty,
you can check the flyback signal at TP2 = pin8 and 9 of the microcontroller.
When you lower the damping = higher resistor value, you should see some ringing at the end of the flyback slope, when returning to steady state.
Make sure you divide the power over 2 1/4 W resistors in parallel - or a single 1/2 W resistor.
E.g. 2x 1K2 in parallel would give you 600 ohms instead of the 500 now.

Regards,
- Bernard

[MartyJ1963]

Hi again Bernard,,,,Regarding the 'Battery charger' circuit on your webpage, can I charge a 12v (3 x 18650 cells) battery pack with it? Thanks again. Marty

[MartyJ1963]

Hiya Bernard,,,I think I got a bit confused,,lol,,,I had a look on your website when you posted that you were selling 'Semi' kits because a few friends of mine were wanting a small, light weight detector with good sensitivity. They live on the other side of England from me so I recommended they build the Pickini. I'd never seen that 'Older' PCB (Pickini2) before so I thought it was a new version. Can you tell me where abouts on the Pickini 4 I would place the Oscope probes to check the Damping resistor please?,,I've not had any issues yet regarding the coils I use for the Pickini, but recently I made a better coil (8") that is more sensitive than the 300uh I use for it. It's a 3dss/260uh/16 strand wire - it's giving me nearly 14 inch depth on a the same ring I found with the Pickini 4 last year. I wanted to compare the the signals between what the 300uh give me and the new coil. P.S-Thanks for posting how to add the 'Vibration motor', my sister is totally deaf so I'm hoping she'll benefit from this. Thanks again Bernard. Regards,,,Marty

[BC547]

There is some good info from Marty on the basket coil he used http://www.geotech1.com/forums/showt...870#post248870
And here is the coil I normally use - slightly larger than 8" http://users.telenet.be/willaert/MD/...n/V3/coil.html

The main difference is that the basket coil is a fast coil - very short flyback pulse - that is better for detecting gold. As Marty proved with his gold ring find.

In the software, you can decrease the value of DC_OFFSET_MARGIN that is now around 1V - that is the DC slicing level - volts below the steady state DC value of the flyback pulse.
If you make this value too small, you will get continuous chatter.
Do not use/test the detector indoors. This gives you a false impression of instability. Take it outside to test.
As for dampening: you could play with the 2 x 1K resistors in parallel. Never tried this as they seem to give good results on a "generic" 330 microHenry coil.