Simplest PI detector possible?

[brucester]

Cool, thanks for that

Love the simplicity of these

My goal is to make a really bare bones simple micro PI with complex software :P

That way, anyone can attach an ADC to a micro and download my software and have a PI.

[brucester]

Sry, i got carried away with videos :P

Wait until i make something half decent :P

I noticed the russians are claiming 30cm on a coin.

I get nowhere near that kind of performance. Obviously because of my 10cm coil and i guess 11cm is have decent on a can. But would be happier if it were 11cm on a coin :P

Perhaps its the TL072s fault?

I would try a different opamp but unsure what would be suitable.

Anyone have any suggestions?

[dfbowers]

I love simple projects. About the pi micro.. I have been thinking of using an Arduino.. at least for the timing. I don't think the built in ADCs have enough resolution though.

[brucester]

Yep, tried that already.

First project i did before this was pulse a coil with arduino controlled mosfet then tried to read the clipped signal with analog read :P

If only life were that easy :P

[brucester]

In saying that though, there is an arduino PI on youtube.

Probably uses an external ADC.

Curious observation.

It detect a huge cast iron pot at 5cm and a little piece of aluminium at 11cm.

[porkluvr]

WM6, your C5 is 1uF. The original Russian Pirate is showing 1nF for that part (connected to OP2 -in).

[ODM]

WM6, your C5 is 1uF. The original Russian Pirate is showing 1nF for that part (connected to OP2 -in).

Notice that this schematic has the same error with R10, it should go to IC2a positive input.

[WM6]

WM6, your C5 is 1uF. The original Russian Pirate is showing 1nF for that part (connected to OP2 -in).

Yes C5 have to be according Russian source 1nF. Thank you porkluvr.

Hope there are no more mistakes in my adaptation.



@6666

It is CW from New Wave Concepts

[brucester]

Did u mean R9 and R10 to be 47k?

I tried those and they weren't as good as the original values.

[6666]

Good video there brucester
It would be interesting for you to try a 10 or 11 inch coil
also Jaycar has a handy multimeter Digitech QM-1324
about $60 but it will measure both C and L, use the 20mH scale
and has an inbuilt Freq counter thats good to about 60KHz

[6666]

@6666

It is CW from New Wave Concepts

Thanks WM6

[brucester]

Thanks 6666

I will make a bigger coil as soon as i find somewhere in aus that sells enamel wire longer than 20m.

[6666]

Just solder and join

[brucester]

hmm, didnt realize that was possible :P

Thanks for that

Is there a clear enamel i could use to cover the joint?

[6666]

Yes just solder and join a bit on, and keep winding,no problem,
There is no real need to insulate the join,
but just a bit of tape will do
or your missus nail polish, heat shrink etc etc