Arduino Nano PI Main Discussion

[Qiaozhi]

When I disconnect the resistor R1,I get 4.75v on TP3

Have you programmed the Nano?
You must do that before you can measure -5V at TP3, as the Nano generates the external clock for the 7660.

[green]

Hi Green ,
Now I see good old mother load red volcanic dirt clay just 3 hours away may not be the exact dirt but will get some soon.
also see why its not east to separate it magnetically.

[ATTACH]54886[/ATTACH]

Looks like Tahoe sand though with all the magnetic rocks. In the picture even the granite pebbles are magnet to some extent .

My ground balance on a bi polar machine cannot handle this ground with the stock coil no matter how slow I sweep it see's too much change in the ground and too much soil volume within any 6 inches to stay balanced.
A smaller mono coil is capable of hunting the ground but at a very slow swing.
Magnetite is not supposed to effect a PI and funny that holds true but not in Gb mode on this machine I still have to run down there after a windy night with the Tdi and see if It suffers the same fate.

My Mpp Board has 4 14538's its quite bulky to run that way that's why I wanted to try the arduino.

Your way ahead of me on my understanding of the physics of GB. I'm just thinking samples and switches still.
You have given me allot to think about and allot of studying I need to do yet.

After I made the pro Q board I'm thinking I may have to add a second integrator but wanted to see if I could do it by sample cancellation either way It should still be a place to start.

My TdI had some sand I could hear in it so I pulled it apart last night for the first time.
All the test points are there Im going to look at timing samples and pulse delay and high and low timings to see how it all comes together.
I will not post those here Unless Carl was good with it. For your study I would Email to you but its going to be a couple days to list the test points.

Tried what I thing would be comparing a MPP vs a 1C integrator in Excel. First delay 4us for small nuggets. Hole is lower for MPP. Would expect MPP noise to be 4times higher with GB enabled. Peak noise is about 3times higher when I enable GB on my detector, so maybe a little less noise with a higher TC hole. Can attach excel program if anyone wants. Have in the past but might have made some changes.

[lc516]

On TP3（ICL7660 PIN5）I get -1.34v，

what is wrong ？

ICL7660 PIN8 is 5v

When I disconnect the resistor R1,I get 4.75v on TP3

[godigit1]

https://www.geotech1.com/forums/show...814#post199814 I can adjust target sample time to cancel ground signal from my back yard with GB switched on and the see target as long as it doesn't fall in the hole with my PI. Figure8 Rx coil reduces ground signal and signal from a zip lock bag from back yard is about 1/5 the signal. Figure8 coil can cancel the California bag if positioned between the figure8 Rx coils. Don't know how difficult it would be to keep the signal low enough swinging the coil over the California ground, no problem in the yard with GB on(not usable with GB off). I think 1/5 the signal is still fairly high? Dirt from back yard, almost nothing sticks to magnet.

I see the decay chart reply #46 from above thread states Calif ground 80 times Al ground but chart shows over 3 times. Two many stupid pills? I measured 5 times this morning at integrator out.

Hi Green ,
Now I see good old mother load red volcanic dirt clay just 3 hours away may not be the exact dirt but will get some soon.
also see why its not east to separate it magnetically.



Looks like Tahoe sand though with all the magnetic rocks. In the picture even the granite pebbles are magnet to some extent .

My ground balance on a bi polar machine cannot handle this ground with the stock coil no matter how slow I sweep it see's too much change in the ground and too much soil volume within any 6 inches to stay balanced.
A smaller mono coil is capable of hunting the ground but at a very slow swing.
Magnetite is not supposed to effect a PI and funny that holds true but not in Gb mode on this machine I still have to run down there after a windy night with the Tdi and see if It suffers the same fate.

My Mpp Board has 4 14538's its quite bulky to run that way that's why I wanted to try the arduino.

Your way ahead of me on my understanding of the physics of GB. I'm just thinking samples and switches still.
You have given me allot to think about and allot of studying I need to do yet.

After I made the pro Q board I'm thinking I may have to add a second integrator but wanted to see if I could do it by sample cancellation either way It should still be a place to start.

My TdI had some sand I could hear in it so I pulled it apart last night for the first time.
All the test points are there Im going to look at timing samples and pulse delay and high and low timings to see how it all comes together.
I will not post those here Unless Carl was good with it. For your study I would Email to you but its going to be a couple days to list the test points.

[lc516]

On TP3（ICL7660 PIN5）I get -1.34v，

what is wrong ？

ICL7660 PIN8 is 5v

[6666]

Thanks Bruce. If I shielded it with Copper tape, what would I ground to the tape? And, would I have to leave a gap like you do when copper shielding a monocoil? Is it Battery negative and the coil connector cos' I'm not certain with ever only using Aluminium enclosures? Regards, Marty

Hi, just treat it the same as a solid metal box, ground will be circuit ground, no gaps needed, but watch out for head phone jacks and how they are wired

[green]

If you look at a Goldscan 2 schematic, you will see that it uses the same integrator circuit as the MPP, and the GS2 includes ground balance.

I stand corrected if it works. Found a schematic, looks like an integrator for target signal and one for ground signal(both have same gain). Don't know what switch on times are. On times effect frequency integrator response. Still don't know why it works unless on times are the same and gain change is after integrators.

[Qiaozhi]

MPP integrator doesn't work for GB, use a 1C integrator. https://www.geotech1.com/forums/show...059#post264059

If you look at a Goldscan 2 schematic, you will see that it uses the same integrator circuit as the MPP, and the GS2 includes ground balance.

[green]

I need to get A gb machine up and running on the bench to help me learn and try to recreate your sample timings.
Might be a good idea for me to re fire up the Mpp GB board soon tp help work out timings for the Pro Q.
Allot to do right now I also just restarted my Voodoo as well that I had set aside for troubleshooting and the nano Pi boards should be here the 14th ( Busy Busy) I need a bigger bench.

MPP integrator doesn't work for GB, use a 1C integrator. https://www.geotech1.com/forums/show...059#post264059

[green]

I was wondering where in CA your sample came from?It sounds like a pretty hot ground sample if it saturates your detector at 3/4 a inch maybe I'm thinking about it wrong, Did you use a magnet to clear out any possibly small iron. Have you tried detecting your nuggets and foil sandwiched or under the sample? What % of your soil is magnetic? If you weigh 20 grams and separate out the magnetic soil it should give you a idea or me of the the diamagnetic properties in your sample.I could maybe find something close by or even get dirt form the same area. Can you move your target signal "I" independently of you ground signal "I" or are they synced up.If so can you find a happy spot where the soil does not react.I need to get A gb machine up and running on the bench to help me learn and try to recreate your sample timings. Might be a good idea for me to re fire up the Mpp GB board soon tp help work out timings for the Pro Q.Allot to do right now I also just restarted my Voodoo as well that I had set aside for troubleshooting and the nano Pi boards should be here the 14th ( Busy Busy) I need a bigger bench.

https://www.geotech1.com/forums/show...814#post199814 I can adjust target sample time to cancel ground signal from my back yard with GB switched on and the see target as long as it doesn't fall in the hole with my PI. Figure8 Rx coil reduces ground signal and signal from a zip lock bag from back yard is about 1/5 the signal. Figure8 coil can cancel the California bag if positioned between the figure8 Rx coils. Don't know how difficult it would be to keep the signal low enough swinging the coil over the California ground, no problem in the yard with GB on(not usable with GB off). I think 1/5 the signal is still fairly high? Dirt from back yard, almost nothing sticks to magnet.

I see the decay chart reply #46 from above thread states Calif ground 80 times Al ground but chart shows over 3 times. Two many stupid pills? I measured 5 times this morning at integrator out.

[godigit1]

Charted ground decay(change in integrator out)vs target delay time, 10us target sample. Can detect a 1 to 2mV change at integrator out on the bench.

I was wondering where in CA your sample came from?

It sounds like a pretty hot ground sample if it saturates your detector at 3/4 a inch maybe I'm thinking about it wrong, Did you use a magnet to clear out any possibly small iron.
Have you tried detecting your nuggets and foil sandwiched or under the sample?

What % of your soil is magnetic?

If you weigh 20 grams and separate out the magnetic soil it should give you a idea or me of the the diamagnetic properties in your sample.
I could maybe find something close by or even get dirt form the same area.


Can you move your target signal "I" independently of you ground signal "I" or are they synced up.
If so can you find a happy spot where the soil does not react.

I need to get A gb machine up and running on the bench to help me learn and try to recreate your sample timings.
Might be a good idea for me to re fire up the Mpp GB board soon tp help work out timings for the Pro Q.
Allot to do right now I also just restarted my Voodoo as well that I had set aside for troubleshooting and the nano Pi boards should be here the 14th ( Busy Busy) I need a bigger bench.

[green]

Does this represent a "viscous ground"? An initial faster, linear decay and then a slower exponential decay? Or in other words, a short TC and a long TC?

I think the ground decay is straight line log-log. Including a recording of the California ground I made with my Target Response Tester, amplifier out. Not perfectly straight, probably do to my tester. The quarter starts out straight line log-log and then finally decays straight line linear log. Can't record enough decades at amplifier out to see if ground finally decays straight line linear log. Recording integrator out for targets<10us TC seems to be close to the same as amplifier out(straight line linear log)Thicker targets and ground don't chart the same at amplifier out and integrator out.

[lc516]

I have found the answer to my question.
Please delete this post

[MartyJ1963]

Thanks Bruce. If I shielded it with Copper tape, what would I ground to the tape? And, would I have to leave a gap like you do when copper shielding a monocoil? Is it Battery negative and the coil connector cos' I'm not certain with ever only using Aluminium enclosures? Regards, Marty

[Tinkerer]

Charted ground decay(change in integrator out)vs target delay time, 10us target sample. Can detect a 1 to 2mV change at integrator out on the bench.

Does this represent a "viscous ground"? An initial faster, linear decay and then a slower exponential decay? Or in other words, a short TC and a long TC?