Arduino Nano PI Main Discussion

[bklein]

Also, what are the marked PIN numbers of the front two pins seen in your photo. The left one seems to have a marking like a “5” which wouldn’t be right.

[ionut_mtb]

I just finished this detector. It performs good when tested indoor. I don’t know why main sample width is little bigger (1-2us) than efe sample. It might be noisy in real conditions?

Main:
Efe:
Main pulse vs opamp out:
Board:

[Qiaozhi]

I just finished this detector. It performs good when tested indoor. I don’t know why main sample width is little bigger (1-2us) than efe sample. It might be noisy in real conditions?

Main: [ATTACH]56516[/ATTACH]
Efe: [ATTACH]56515[/ATTACH]
Main pulse vs opamp out: [ATTACH]56517[/ATTACH]
Board: [ATTACH]56518[/ATTACH]

They should be the same, but the discrepancy should not make a noticeable difference in use. If you want to tweak the settings, then change efeSampleOffset in the sketch. It's currently set to 4us.

[dingbatca]

More info. Two shielded cables to the connector boot. Only one is wired into the connector. Jumpers across pins 1-5 and 2-3-4. I don't think this info helps. :-(

Any other ideas?

[Qiaozhi]

More info. Two shielded cables to the connector boot. Only one is wired into the connector. Jumpers across pins 1-5 and 2-3-4. I don't think this info helps. :-(

Any other ideas?

Did you see post #495?
This information would help in determining the problem.

[bklein]

Also, what are the marked PIN numbers of the front two pins seen in your photo. The left one seems to have a marking like a “5” which wouldn’t be right.

Never mind - I can see how it would be correct.

[dingbatca]

I did see post #495. Do you still think that will make a difference knowing pins 1, 2, and 3 are just shorted in the coil side plug?

[Qiaozhi]

I did see post #495. Do you still think that will make a difference knowing pins 1, 2, and 3 are just shorted in the coil side plug?

In your simple test coil there doesn't appear to be a shield. If that works ok in the field then there might be something fishy going on with the GPX coil as regards shielding. If it's not that, then I'm not sure what it could be.

Having re-read your post I see what you mean. The pins are actually shorted together in the coil plug, not the socket.
This is a mystery.

[bklein]

Here is the whole connector wiring diagram. I started to wonder about the TX coil wiring (that you cut). Make sure you cut the right one...

[bklein]

Along with what I just posted... I started to think about this Detech coil. As the TX is just cut free, would it be better to terminate it with a damping resistor or short? Would it ring and then couple to the RX coil?
I know guys are running GPX coils on the TDI but maybe the TDI shorts the TX coil out? I've never read anything about this subject, so.....

[dingbatca]

Does anyone else have a Minelab GPX, GP, SD Mono coil they can test the ANPI against?

My end goal was to have a really good coil. I want to use said coil as my "gold" standard to test all my home brew coils against. The 8" was nice as I could build home brew coils of the same size and shape to test.

[dingbatca]

Just one minor clarification. I have not modified this coil in any way. The cut line is stock from the manufacture. I will try to get my meter in there to see if the cut line is hooked up, but I doubt it.

[Carl-NC]

My best guess right now is you have a bad coil, maybe the shield has broken loose. Have you tried it on a GPX or TDI?

[bklein]

My receptable wiring seems different from yours. Key is at the bottom, pins 4 and 5 to the left of it (your receptacle is oriented the same)
Nothing on the right side. Yours looks different. Several GPX coils work fine on mine but I haven't taken it to a local park yet.
Lots of steel around my workbench area but if I distance the coil a couple feet from it it works fine.

[David_1]

So I read up to page 9.. on my phone.. does any hear understand rfid. And the chips they put in dogs and cats ? About 20 years ago I was involved in making the readers.. its very similar to a metal detector.. in as much as on coil powers the pet chip via another coil.. but in turn the chip in the animal nulls or doesn't null the transmitting coil to transmit the rfid number back to the reader... !