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

[awar]

Finally i got some free time to finish "standalone" (no Arduino) version of this PI.
I made it on my own pcb, don't like the proposed one.
Ok, it is alive and kicking.
But it sucks BIG TIME with standard 28cm coil.
There is very short "Balancing..." sequence displayed on LCD after switching up the detector, it shows up and disappear fast. So, it's some "balancing".
Which gives me idea that author f'cked up BIG TIME in code with it. Because obviously this detector is not working acceptable with "smaller" coils.
After trying with 28cm coil i replaced it with tiny and small coil from previous experiments, showed on my video earlier.
It's a small coil salvaged from old 5.25" floppy. Completely irrelevant with it's specs, i just used it than to skim test the circuitry.
And now i was surprised again; detector shows bit better performances with that "midget" coil than with standard 28cm coil??
Ha, ha, ha!
This will need bit more effort... i am sure.
Any other experiences?

Here are some photos;

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[ATTACH]34134[/ATTACH]
[ATTACH]34135[/ATTACH]
[ATTACH]34136[/ATTACH]
[ATTACH]34137[/ATTACH]
[ATTACH]34138[/ATTACH]

cool! my pcb is on the way

[ivconic]

Reading whole topic again; i see that coil must be made more precisely in this case.
Most probably i am getting bad results because of coil here.
Ok, this will be checked soon.
Small tip for Atmega programming; it is indeed very easy to program Atmega using Arduino UNO.
No fuses, no additional setups. What you need is Arduino UNO and another Atmega328P.
Just burn bootloader into new Atmega and than flash the hex code.
And that's all.
I am having 4 empty Atmega's here, tested all in a row. All working just fine.
Despite the fail to get good results on the very first switch on; i am still thinking that this is very interesting design, worth to be made.
It is straightforward relating the electronics.
Now is coil to be made correctly...

[ivconic]

Finally i got some free time to finish "standalone" (no Arduino) version of this PI.
I made it on my own pcb, don't like the proposed one.
Ok, it is alive and kicking.
But it sucks BIG TIME with standard 28cm coil.
There is very short "Balancing..." sequence displayed on LCD after switching up the detector, it shows up and disappear fast. So, it's some "balancing".
Which gives me idea that author f'cked up BIG TIME in code with it. Because obviously this detector is not working acceptable with "smaller" coils.
After trying with 28cm coil i replaced it with tiny and small coil from previous experiments, showed on my video earlier.
It's a small coil salvaged from old 5.25" floppy. Completely irrelevant with it's specs, i just used it than to skim test the circuitry.
And now i was surprised again; detector shows bit better performances with that "midget" coil than with standard 28cm coil??
Ha, ha, ha!
This will need bit more effort... i am sure.
Any other experiences?

Here are some photos;

[ivconic]

hi,ivconic

in your schematic ,WHY don't use C26(100nF)?

Probably i missed it.
Don't think it's important.

[lc516]

hi,ivconic

in your schematic ,WHY don't use C26(100nF)?

"...You don't imagine any wrong information how affects enthusiasts even at countries you don't believe it..."

Well said!
I lost my nerves here so many times trying to fight against that!
...
Is there any chance we to see source code here?
Arduino UNO and MINI Pro are here on the bench, waiting me to adapt schematic.
First step is to make better view on it;
[ATTACH]33729[/ATTACH]

[jladre]

Any news of this pi?? Now i finish programing the chip. Next is preparing the board.. Extreme burner works well in windows 8.1.

[jladre]

Thanks ivconic for the well informative reply..i look that parts tommorow...

[ivconic]

hi all! just need your suggestion, can i used 20.99 MHz crystal instead of 20MHz? then what would be the good replacement of bs170 because i cannot find it in my country.

You can use 2N7000 instead BS170.
If you use crystal different than 20MHz; all the clock-critical functions will misbehave.
On the first place timers with interrupts.
Now, i am not sure exactly in what degree are those directly dependent on main clock in this case.
But usually they are 100% dependent.
So, best advice would be you to try to obtain 20Mhz crystal.
Detector will work. It is working with 16Mhz at my Arduino.
But it will not work acceptable for outdoor use. Only in testing purposes, on the bench.
I tried to translate some of the posts from Persian forum, where they debate about eventual "discrimination" at this pi detector.
Author himself several times suggested that "discrimination" will work only if all the components are chosen properly to match original setup.
Though there are several reports where is noted that it is very tough to achieve due various reasons.
So, design is critical in terms of properly selected components, quality of made and degree of respecting original author's idea and concept.

[jladre]

hi all! just need your suggestion, can i used 20.99 MHz crystal instead of 20MHz? then what would be the good replacement of bs170 because i cannot find it in my country.

[jladre]

Thanks for this project..so impressive!

[lc516]

YES,"cable coil" is key information of I want,thanks!

About various PI coil sizes you may read a lot of infos on Delta Pulse topic.
Bury in mind that coil size, number of turns, resistivity, inductance; directly depends on detector's pps&damping and vice versa.
Since FelezJoo PI is having option to change pps and delay in wider ranges; you can't cover it with one single coil and expect same performances across whole range.
For coil diameter greater than 1m you may choose "cable coil".
Proper infos may be found on these forums.
Use "search" option.

[ivconic]

i dont know why i had a feeling that you want to adapt the proiect to an arduino.

Yes your feeling is right. I wanted that. And than in middle of the road i found out that i was wrong.
But than again i think whole this experience so far was not for nothing.
Now we know more than we knew at the beginning.
Hopefully...

[awar]

i dont know why i had a feeling that you want to adapt the proiect to an arduino.

[ivconic]

why dont you try to overclock the arduino? 30mhz can be ok for this proiect,i think. ( http://garagelab.com/profiles/blogs/...verclock-30mhz )

"...This is more fun oriented project than something useful (or not) since ATmega328 was not designed for clock frequency above 20MHz (see datasheet). So, 30MHz is push it far from the limit. ..."

What would be the purpose and meaning?
Why making things more complicated than they are?
Atmega328P is cheap and can be found everywhere.
Also occupies much less space on detector's pcb.
Arduino is good when you want to check some code and see rough properties and behavior.
Arduino is also good to write and develop code for Atmega.
It saves time and make things much easier and simpler.

[ivconic]

I want make a coil (

diameter greater than 1M

) to connected the PI, BUT that's I've never done before.

Please recommend some practical solutions about loop or coil. I want to know how they are made.

About various PI coil sizes you may read a lot of infos on Delta Pulse topic.
Bury in mind that coil size, number of turns, resistivity, inductance; directly depends on detector's pps&damping and vice versa.
Since FelezJoo PI is having option to change pps and delay in wider ranges; you can't cover it with one single coil and expect same performances across whole range.
For coil diameter greater than 1m you may choose "cable coil".
Proper infos may be found on these forums.
Use "search" option.