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

[dbanner]

Ivconic, I forgot to ask the obvious, which is, did you try the lm357 from you first successful build in the subsequent builds? How about the coil from first buid as well? I am sure you did. But this did not make any difference. So the conclusion is don't build. I will not build.

[ivconic]

it's very strange!
Are you sure don't have some fake components? There are many of it on market!!

At the beginning i believed that too: that there are too many fakes on the market.
But than it is not complete truth.
I obtained several LF357s from different suppliers, from different series and date.
It is not possible that all those are fake!
Besides i also heard the experiences from other diyers on this subject too, as were pretty similar as mine.
Obviously the author took one (probably pretty random) LF357 and wrote the delicate part of the code according to that particular piece of LF357 (internal hum, dc offset, amplification rate, sensitivity etc...)
And now we are in troubles because of that. Now we have to randomly guess as closest as possible specification to that LF357.
Easiest way to "mask" this mistake is to say "it is fake" in public.
...
Come to think... this is splendid method to make a lot of money from selling LF357s world wide!!!

[bernte_one]

the best lf357 i got from China via ebay
i think if this was fake lf357 the match up to 95% of original

[freso]

I think atmega328 are not supported in Extreme burner I also used Usbasp but in AVRdude or in mkAVR.
[ATTACH]35998[/ATTACH]

hi my friend i used mKavr and flashed atmega succesfully now my board works fine exept it dont detect coils even if i wire a 0.8 ohm resistor with the coils .... can you show me mKavr configuration because i think i am doing something wrong since i set the lock fuse to 0 .......... please some help it's the 3 rd board not working

[Qiaozhi]

A message to dalgic35 ... please stop posting advertising links in the Tech Forum (or any other forum for that matter). I have already had to remove several from this one, and the Schematics forum.
If you want to advertise a product, please do it in the Free Advertising forum, where you can make one post.
Any more random advertisements will result in a ban.

[RS_Phil]

hi my friend i used mKavr and flashed atmega succesfully now my board works fine exept it dont detect coils even if i wire a 0.8 ohm resistor with the coils .... can you show me mKavr configuration because i think i am doing something wrong since i set the lock fuse to 0 .......... please some help it's the 3 rd board not working

I encounter same problem also when I set a wrong fuse bit,.even you erase or verify there will always an error,, the solution is used AVR fusebit doctor to erase/program and restore default fusebit and program it again, or buy new atmega328.

[jladre]

new pcb drawing...
http://forum.jokerdedektor.com/pi-pu...msg834/#msg834

i think this is the good one.

[RS_Phil]

i think this is the good one.

...

[Spyke]

i think this is the good one.

Did somebody built this board and compare the performance to ivonic´s board?

[pigeon]

i think this is the good one.

hi all friend

i search pcb for this version in format pdf

thank you

[sabios]

Felezjoo

I could say that difference has this version of the others,
because the eye has some changes ...

such as is to say 18v, while in other versions is to 24v.

also the fact that it has the IRF840 but has the IRFP460 and BDX54C and other minor details.

improvements or disadvantages might have.felezjoo.rar

[Spyke]

I finished my PCB, but it didn´t work well.
It gives me coil error, I tried with 3 different coils I use with my chance pi.
What I noticed, before error appears, there is a short buzz from coil.

Can somebody helping me out? Can somebody give me details about building a working coil (diameter, kind of coil, kind of cable, etc.)

[ivconic]

I finished my PCB, but it didn´t work well.
It gives me coil error, I tried with 3 different coils I use with my chance pi.
What I noticed, before error appears, there is a short buzz from coil.

Can somebody helping me out? Can somebody give me details about building a working coil (diameter, kind of coil, kind of cable, etc.)

That is the common problem which we mentioned here several times.
It is related to coil and LF357, other words; those are not matched.
It is a problem. You have to put an effort to make suitable coil.
Also you will probably need to try several LF357s too.

[freso]

I finished my PCB, but it didn´t work well.
It gives me coil error, I tried with 3 different coils I use with my chance pi.
What I noticed, before error appears, there is a short buzz from coil.

Can somebody helping me out? Can somebody give me details about building a working coil (diameter, kind of coil, kind of cable, etc.)

same problem with me my friend i hear short buzz from coils but dont detect no one i tries 3 coils and LF357d Ne5534p Tl071 .....just Lf 356 detect my 20cm cat5 cable coil sometimes but hang on beeping speaker and keep beeping every 3 seconds weired

[freso]

Hi eclipse. That is a 56cm coil with 400uH inductance made of 2 turns of 26awg CAT cable.. Im planing to make 68cm coil i have a 1mm copper wire her..i hope this would be better. Im using lf356 but im trying to get lf357 problem is only ebay is the option.

hi jladre is the coil you mention in here similar to this but you made it with 2 turns instead of 3???? me and some mumbers in here are suffering to get it detect coils can you show us how you did the coil????