Voodoo Main Discussion

[Mdtoday]

That was fast.

Maybe a bit too fast...
LCD code is done, ADC has been coded, port pins all ok, EEProm needs to be coded as the routine has been dropped from MC library for a lot of devices.
Its ok with PIC16F not 18F.
It is now replaced by the DATAEE library and MCC does not support a lot of the earlier devices including, unfortunately, the PIC18F4520.
I am currently working on a routine.
Good news is that I have also ported most of the Voodoo code to PIC18F45k22
Looks like I'm going to build the hardware sooner than I planned so I can test both of the ported codes.
Will post the PIC18F4520 version once I write that EEprom routine.



Cheers

[lamoiz]

Hi
Did you get a good null ?
was it easy to find he coil null location when moving the RX coil around ?
Have you tried it with a target , is it sensitive ?
and would you mind saying the turns and inductance etc Thanks

hi, first of all, i am in testing phase. on the omega and also on a super D.
for the omega, the tx is 300mm and the nulling 110mm. it is made of litz175 / 46 wire. its inductance is 440uh. there are 26 turns.The rx coil is 0.2mm enameled copper. it is tuned with a capacity of 22nf. the dimensions are 140mm-170mm it is oval. there are 166 laps.(10.5mh) the resonance is 10.2 khz. the nulling obtained is 12mv .. for the moment, since nothing is really fixed. the sensitivity is average, a piece of copper is captured at 22cm, which is average given the dimensions, (in hybrid mode on the voodoo). the test on gold and platinum is average too, no more than 15 cm ... but this is only the beginning, because I have not adjusted anything in the parameters of the voodoo. here is.

[6666]

Good evening 6666
no problem., what do you want to know?

Hi
Did you get a good null ?
was it easy to find he coil null location when moving the RX coil around ?
Have you tried it with a target , is it sensitive ?
and would you mind saying the turns and inductance etc Thanks

[lamoiz]

Please give a report on coil.

Good evening 6666
no problem., what do you want to know?

[6666]

everything works perfectly, still adjustments to be made .. but it works well. It's been two weeks lost because of this bad cable pff. I tested the large size omega .. it works.
thank you george, great project !!
[ATTACH]53892[/ATTACH]

Please give a report on coil.

[6666]

It looks like you are well on your way. Let me know if you want to see any comparison wave forms as you proceed through the steps. I am happy to take some more pictures.

Thanks for the offer, looking forward to finish and test in the field.

[surfdetector]

For what?s its worth this is where I am up to with the Voodoo, and telling it like it is.


Where I can, I pretest all components it gives the best chance of a successful build and just as well I did, so far I have found a dud LT1054 by bread boarding a voltage doubler and a 10K resistor that was varying in resistance with the 328 tester, very odd but it went in the trash, takes a lot of time but worth it.


I have been having a horrendous time trying to read the component value and designations as the book schematic print quality is not good, a bit too small , thin and a bit fuzzy, even using a Jewellers loupe, you have to check the BOM. The schematics in the ITMD where excellent.


With reference to fig 3.1 the power supply, after you load all the parts shown in fig 3.1 you will only see the -5 volts at TP 14, nothing at TP15 which is +5 volts only with the PIC sync pulse working.


However there is a trick to test the LT1054 and make a positive voltage, if you take a lead from TP14 and quickly connect and disconnect it on TP9, you can kick the LT1054 and produce a quick random positive voltage on TP15, up to +5 volts. The quicker you are the higher the voltage.
Do this at your own risk.


I am not a fan of the two fets in the power supply, all that is required is a series 1N5822 Schottky 40V 3A diode to act as the idiot diode even if it does lose .2 of a volt. These hard to get fets are just something extra to fail or cause trouble .


Next I wanted to test the PIC, fig 3-12, I loaded the minimum number of parts to hopefully make it work, being R36, caps C2,C4, C7,C5, C8, xtal1, and it fired up, giving a nice sync pulse on TP9, as per fig 3.22 and +5 volts on TP15, and very happy it worked so far. Thats were I stopped, still a long way to go. On to the TX next.

It looks like you are well on your way. Let me know if you want to see any comparison wave forms as you proceed through the steps. I am happy to take some more pictures.

[6666]

For what?s its worth this is where I am up to with the Voodoo, and telling it like it is.


Where I can, I pretest all components it gives the best chance of a successful build and just as well I did, so far I have found a dud LT1054 by bread boarding a voltage doubler and a 10K resistor that was varying in resistance with the 328 tester, very odd but it went in the trash, takes a lot of time but worth it.


I have been having a horrendous time trying to read the component value and designations as the book schematic print quality is not good, a bit too small , thin and a bit fuzzy, even using a Jewellers loupe, you have to check the BOM. The schematics in the ITMD where excellent.


With reference to fig 3.1 the power supply, after you load all the parts shown in fig 3.1 you will only see the -5 volts at TP 14, nothing at TP15 which is +5 volts only with the PIC sync pulse working.


However there is a trick to test the LT1054 and make a positive voltage, if you take a lead from TP14 and quickly connect and disconnect it on TP9, you can kick the LT1054 and produce a quick random positive voltage on TP15, up to +5 volts. The quicker you are the higher the voltage.
Do this at your own risk.


I am not a fan of the two fets in the power supply, all that is required is a series 1N5822 Schottky 40V 3A diode to act as the idiot diode even if it does lose .2 of a volt. These hard to get fets are just something extra to fail or cause trouble .


Next I wanted to test the PIC, fig 3-12, I loaded the minimum number of parts to hopefully make it work, being R36, caps C2,C4, C7,C5, C8, xtal1, and it fired up, giving a nice sync pulse on TP9, as per fig 3.22 and +5 volts on TP15, and very happy it worked so far. Thats were I stopped, still a long way to go. On to the TX next.

[Altair]

everything works perfectly, still adjustments to be made .. but it works well. It's been two weeks lost because of this bad cable pff. I tested the large size omega .. it works.
thank you george, great project !!
[ATTACH]53892[/ATTACH]

Very good work Lamoiz! I am curious about your omega coil; a test video would be appreciated!

[Altair]

hi to all can this machine detect gold

for its properties, I believe yes, if the gold is not very tiny.

[sbalio1]

hi to all can this machine detect gold

[lamoiz]

everything works perfectly, still adjustments to be made .. but it works well. It's been two weeks lost because of this bad cable pff. I tested the large size omega .. it works.
thank you george, great project !!

[Qiaozhi]

Had some spare time tonight so started porting the Voodoo code to XC8 compiler.
Pretty much down to adding the ADC/LCD header files and a small number of syntax changes to go.
Should be completed over the next night or two if time allows...
I haven't built the hardware but can compile and post the project files along with the hex file if someone would like to try it. Will be a little while til I get round to the hardware.

[ATTACH]53891[/ATTACH]

Cheers

That was fast.

[lamoiz]

hi Surf, hi George, yes the output is correct now, it's crazy how sensitive the wiring is between the winding and the electronics. may be a capacitive effect .. ?? I just did a test on a winding in litz wire, .. the result is very very good ..

[Mdtoday]

Had some spare time tonight so started porting the Voodoo code to XC8 compiler.
Pretty much down to adding the ADC/LCD header files and a small number of syntax changes to go.
Should be completed over the next night or two if time allows...
I haven't built the hardware but can compile and post the project files along with the hex file if someone would like to try it. Will be a little while til I get round to the hardware.



Cheers