felezjoo PI(the best pulse induction metal detector that I made until now)

[geoscash1]

3" is pretty good, but what is the weight of your nugget and what size and shape of a coil are you using?

Ivconic wanted a distance for the 6mm square target and I gave an ideal number. At times one must aim higher in order to do well. Lets see what Felajoo can do on this target even in air.

Regards,

Dan

Hey Dan,

It is a 7-1/4" round mono coil, 315uH teflon 7 strand silver plated 24awg on one of my mirage boards CBSII, fact I just finished it yesterday. I had made a 5x9 eliptical 3DSS, using the template that Krinz added to the minipulse plus thread, It picks it up at about 1 inch so I went with a bundle wound and it worked better at 3" after a bit more tuning. The nugget is 15 grains but is laced with quartz so I don't know the exact amount of gold but since it is detecting it, I'm happy with it. tested today outside away from any emi and it is tickin away at nickels right at 11/12 inches and a 14k gold womans wedding ring at 10" in air so hoping that transfers well to the ground.

I have been following this felezjoo thread just to see how well it performs and am looking forward to more info and the testing of it. Sounds like it may work once the bugs are worked out and the timing can be sorted along with a proper coil.

[baum7154]

I am not familiar with the MIRAGE circuit but have heard it is a good machine. Does it have a 2 stage preamp? Does it have TX pulse width, sample delay, and PPS adustments? Since it sees a nickel at 11" I wonder if shortening sample delay and pulse width would increase that 3" you are getting on the 1 gram nugget. On an 8" coil I would expect that nugget to show up at 5" or more in air.

I think the amount of gold in your quartz laced nugget can be approximated if you can perform a specific gravity measurement. Gold is about 19 times (19.32 for pure AU) heavier than water. Precisely weigh the dry nugget. Then weigh the nugget suspended in water. Subtract the water weight from the air weight and divide the air weight by the difference to get the specimens SG. Quartz has lower specific gravity of about 2.65. Just a rough description of the process. You can find this process at gold-nuggets.org and probably many other sites. This process will tell you about how much gold is in your sample

Regarding Felajoo for small sub gram gold: It appears Felajoo is not designed as a small gold machine. I think it will require a proper fast coil and a 2 stage preamp modification in order to open the doors to detection of these types of targets. It does not now appear that there is any effort in this direction, so it could be a long wait.

Regards,

Dan

[Koala]

18kHz, GMP program at Deus (Sens at 96):

- 6mm cut = ~12cm in the air.
- 10mm cut = ~16cm in the air.

Illustrative enough. It's not expectable any of the known diy's to beat that.
So finally; i don't expect neither FelezJoo PI to reach or beat that too.
Tough!

For fun I test a couple of my detectors

Barracuda 6mm not detected and 10mm has to touch the coil. Not surprising as delay is set at a happy average and just a copper enamelled wire for the coil.


Bandido 6mm = 6cm
10mm =10cm


Weird coincident of square size in mm to distance in cm

[WM6]

During such air test, test samples should be "glued" at some sort of plastic ruler, cause some sensitive detectors are able to detect bare hand (Ferro in blood) and results are no more valid.

[green]

Including an updated target time constant list. Need to finish some and could add a couple. A 6x6mm can has a time constant of 1.5usec, 10x10mm can 2.4usec. The can targets are larger than nuggets but they have a shorter time constant which might make them harder to see. I've read where the coil circuit should be 5 times faster than the target. What about the preamp? Does a slower preamp filter the response giving more signal at say a 10usec delay?

Been wondering about the amplifier response. No replies so I recorded some data. Everything the same except for adding a 100p capacitor across the feedback resistor of the first stage of a two stage amplifier. The slower amp reading wasn't as stable. Don't know how the slower amplifier would effect doing GEB. The slower amp does increase the reading for short time constant targets. Might be worth more experimenting. Seven usec delay, 10usec target and EF sample. IB coil, difference amplifier. My error, not two stage. Transistor pair connected to the op amp. FDBK across op amp.

[ivconic]

About version 3.30 and Arduino; will not work with Arduino as i already reported.
Also as i assumed; it's about presence of bootloader in Atmega328p.
(Haven't tried with optibootloader which occupies much less memory than standard bootloader, will try that just to clarify some other doubts too)
Without bootloader at all no problem, it works just fine.
I used USBasp programmer with barebone Atmega328p setup.
In Avrdudess everything goes so smooth and nice.
This works also with Extreme Burner and variety of other soft.

[seadoggy]

[ATTACH]35758[/ATTACH]

Can i use this PCB to make this PI?a ask because i see here several versions.
Regards

[freso]

Hi ....i am gathering components to make this i cant find diode 5819 i have 5822 wich is 3 amps and 4007 wich is 1 amp with wich one should i replace 5819 ..... And i cant find tantal capacitors can i use electrolityc insteat and can i use voltage till 50 vlots on caps???

[gurdal]

hello ivconic

atmega328p fuse locked

I can not write delete hex

Is it a practical solution

thanks

[gurdal]

atmega328p to write hex

usbasp,ZeptoProg II

they have

eXtreme burner fuse and crystal settings

how should it be.

thanks

[reptooyep]

Hi everyone.
I just finnished the assembly of this MD and i have troubles : when power on, i does not display anything (and no sound).
I haven't finished the coil yet and i'm missing the two 4700uF capacitors but the unit should turn on without those things.
I tryed with two differents chips (i have experience programming and burning AVR).
I've installed the 3.05 software.
Should i have a sound on starting ?
The pin 3 of the LCD is 4.6v, maybe it's just a contarst tuning ?
How to tune the contrast without display ? Could someone tells me how to acces this menu and haw to activate the display light ?

I've already check all the wiring and i have the good voltage on the AVR and the display.


Any help would be great

[ivconic]

Hi everyone.
I just finnished the assembly of this MD and i have troubles : when power on, i does not display anything (and no sound).
I haven't finished the coil yet and i'm missing the two 4700uF capacitors but the unit should turn on without those things.
I tryed with two differents chips (i have experience programming and burning AVR).
I've installed the 3.05 software.
Should i have a sound on starting ?
The pin 3 of the LCD is 4.6v, maybe it's just a contarst tuning ?
How to tune the contrast without display ? Could someone tells me how to acces this menu and haw to activate the display light ?

I've already check all the wiring and i have the good voltage on the AVR and the display.


Any help would be great

Strange?
If you programmed Atmega correctly than it should switch ON and run with no problems.
Disconnect LCD pin 3. from pcb, add 10k potentiometer, middle pot pin on 3. pin of LCD, pot ends to +5v and gnd.
Backlight; disconnect LCD pin 15. from pcb and put 220ohms resistor on it and connect to +5v.
Try to adjust contrast with 10k pot.
If you still can't see nothing on LCD than your Atmega is not programmed well. Or you have some other problem on pcb.
Additionally check LCD pin 5. - it should be connected to gnd.
Yes you should hear short "beep" sound after switching it On.

[ivconic]

atmega328p to write hex

usbasp,ZeptoProg II

they have

eXtreme burner fuse and crystal settings

how should it be.

thanks

[paku]

For $10 000 man can buy 6 to 8 XP Deus-es, depends on options!
XP Deus with largest coil is deeeeeeep! And it barely overcomes the price of $1500.
Minelab Explorer SE with large coil is also deeeeeep! Not sure about price, but certainly is bellow $2000 range.
...
As i posted earlier; i made FelezJoo PI and tested it in details.
It performs bad and poor.
In air it is very interesting, but on real soil it is useless.
But i was deeply interested in it's code, and still am; because i am amazed with how much details are put and processed with moderate (if not weak and poor) Atmega328P.
Author did excellent job. "Digital" part of detector is very nice done. But analogue part is poor designed and useless in real world.
So, if we had source code here; we could gather all together here to improve it to perfection. It would be perfect "open source" project.
But now with attitude like this; this project is going nowhere. I don't see bright future for it. Because nobody is insane that much to pay such price.

can use this for hex

Disassembler Softwares For Mcu Reverse Engineer

http://www.break-ic.com/Disassembler...e_engineer.htm

[Qiaozhi]

can use this for hex

Disassembler Softwares For Mcu Reverse Engineer

http://www.break-ic.com/Disassembler...e_engineer.htm

According to their website, they can "Foreseen all pertential problems".
..... with the exception of spelling and grammatical errors.