Voodoo Main Discussion

[ivconic]

10 minutes of constant working in Pulse mode.
Nothing gets hot, no magic smoke.
Haven't tried with PW wider than 150uS.
...
Took one home made coil for IB.
0.7mH and 12mH.
Skim testing, approx tuning cap (most probably wrong).
Not discriminating by now.
I'll have to read again the book and search for how to properly adjust R22.
Also how to properly trim the tuning cap.
...
What i am missing here is Sensitivity adjustment. In both modes.
Without it it will be pretty much useless on real soil.
Also it would be nice if it had some kind of visual indication in Pulse mode.
Somehow LCD looks stupid indicating nothing in Pulse mode.
But that's the part probably very easy to add in code.
...
That's all for this night. I am tired.
Damn 78L05 killed me!
...
Good job Q. but not finished, i had to tell you this.
Add Sensitivity in both modes. That's important.
I don't understand Treshold function here.
I can't easy see the difference.. actually can't see it at all.
Too tired to search in code.
PIC code is pretty much gibberish for me, must take time to learn it.

[ivconic]

Ok i solved it.
It also may be possible weak point of the design, not sure yet.
All the time it was up to 78L05.
I tried 3 brand new pieces and all behave the same.
Chokes and wont provide +5V. Only at short moments.
Trick was that when in Menu; damn thing provides +5v.
In operating mode not.
At PW 150uS overall power consumption is 150mA.
At PW 100uS overall power consumption is 122mA.
So i solved it very simple; instead 78L05 i put 7805.
And everything works just fine.
I am satisfied with air "depths" i get with small ~18cm coil.
I will work around it something else, but right now i can't test Disc mode, until Spectra V3 coil arrives.
Need to test this on longer working period to see if anything gets hot and ready for magic smoke!

[6666]

I think that they use one of these:
https://www.switchcraft.com/products...spx?Parent=599

Thanks , they are rare around here.

[ivconic]

Ok, this is interesting!
Since i am restless to see this alive and this is loooong weekend; i decided to give it a try again.
This time i made simple JDM programmer (state of the art among my works, see the photos).
I have Dell Optiplex 7010 among other computers. I7, 4th generation, 16GB RAM, 120GB SSD, 1TB WD...
Overall pretty usable machine.
But i never really look it's back side, so i didn't know that it has old com port (RS232) !???
That gave me motivation for this.
The other day i spitted hard on PICPgm Programmer software, since it didn't recognize my old parallel port "burner".
So i made JDM, use several wires to connect it with "Ready for PIC" board, just to use it's DIL socket.
And gave it a try. Total SUCCESS!
Now PICPgm Programmer recognizes programmer and chips flawlessly!
Small notice: i only had to lower the speed (Time Delay Factor) in options, from fast to almost slowest.
So i flashed both 18F4520 that i have.
Than i placed them in dil sockets on two Voodoo pcbs.
Than i performed series of basic tests. All voltages are correct.
LCD is now working. Buttons all working.
Sound is ok.
All the signals from PIC are ok.
With scope i see pretty decent flyback.
But!
Detection... ZERO!
So i looked around and i founded out that offset voltage at NE5532 is -1.4v !!!
And with turning the trimmer to adjust it; it is not changing at all!??
I scoped from coil across the two diodes at the input; yes i see the PI RX signal alright.
So i suspected both NE5532. Fortunately i have 4 of those more.
Not from the same series and same age, those 4 i stripped down from some audio mixer, 100% originals, 100% accurate and high quality.
So i replaced NE5532... same thing. Can't adjust offset. At both pcbs the same behavior.
So right now i am stuck there. Just took short rest to post this post and inform you about the news.

[Qiaozhi]

I was intending to load and fire up 2 boards with the different processors to work through the C code port from 18F4520 to 18F45K22, which would have helped sort the config problem but both my orders for parts and PCBs that I was hoping to receive before Christmas are delayed.
Element14 has just informed me of a 2 week delay in 1 resistor value, I marked the order to send all parts in 1 shipment, so nothing to load the boards with, which is neither here or there because the JLPCB oders is also delayed with DHL.
It has been sitting in Hong Kong since 14th Dec.
That time of year.
I just noticed, I could get a PIC18F45K22 locally , so maybe I'll grab one and fire it up on a breadboard with the power supply, as I can rig that up easy enough and it will help figure out what is required in Configuration at least.

Cheers

Mdtoday

Not a good time of year to order stuff online, especially from China.
I ordered some PCBs from JLCPCB on the 4th December and received them in a couple of weeks. It was surprising that they got here (UK) so quickly, especially since they came via Germany. I was a bit concerned that they may get delayed at the ports due to the upcoming Brexit problems. Maybe it was because I had them delivered via DHL Euro Express.

[Mdtoday]

The PICKit 4 is quite expensive, so I would get the PICKit 3.
Don't know what 3.5 is. Never heard of it.


It sounds like it's an issue with the PIC18F45K22. Most likely a configuration problem.

I was intending to load and fire up 2 boards with the different processors to work through the C code port from 18F4520 to 18F45K22, which would have helped sort the config problem but both my orders for parts and PCBs that I was hoping to receive before Christmas are delayed.
Element14 has just informed me of a 2 week delay in 1 resistor value, I marked the order to send all parts in 1 shipment, so nothing to load the boards with, which is neither here or there because the JLPCB oders is also delayed with DHL.
It has been sitting in Hong Kong since 14th Dec.
That time of year.
I just noticed, I could get a PIC18F45K22 locally , so maybe I'll grab one and fire it up on a breadboard with the power supply, as I can rig that up easy enough and it will help figure out what is required in Configuration at least.

Cheers

Mdtoday

[surfdetector]

I just tested my whites V3i concentric coil and it may be suitable, but does anybody know where you can buy a whites 5 pin coil socket ? and what type are ? thanks

I think that they use one of these:

https://www.switchcraft.com/productsummary.aspx?Parent=599

[6666]

temperature of my workshop 20 .. and measurement of u6 after 5 min of use 24.5 .. measurement with a pt100 on contact.

Thank you thats good information, I am just a bit surprised at how warm the reg is already, the voltage is ok.

[6666]

There is a comparison test on Yotube. 3.5 allegedly works faster.
I will order model 3. Seems like optimal one for my needs.
...
Yes, it must be. I made two voodoo's and i have exactly the same behavior on both.
...
I located one White's Spectra V3 coil and will obtain it for testing.
Other coils that i have are not suitable.

I just tested my whites V3i concentric coil and it may be suitable, but does anybody know where you can buy a whites 5 pin coil socket ? and what type they are ? thanks

[lamoiz]

Thank you for posting the wave forms. It is much more interesting than looking at the Datasheets.
Cheers

thank you Surf, I agree.

[surfdetector]

for info, here is the 5532 and with the same coil and all the same settings the 4562 ... choose your side ...[ATTACH]54032[/ATTACH]5532
[ATTACH]54033[/ATTACH] 4562
see you

Thank you for posting the wave forms. It is much more interesting than looking at the Datasheets.
Cheers

[lamoiz]

It would be expected, since the different slew rate of those components.

Yes, it's true! thank you for showing it ..

[Altair]

for info, here is the 5532 and with the same coil and all the same settings the 4562 ... choose your side ...[ATTACH]54032[/ATTACH]5532
[ATTACH]54033[/ATTACH] 4562
see you

It would be expected, since the different slew rate of those components.

[lamoiz]

for info, here is the 5532 and with the same coil and all the same settings the 4562 ... choose your side ...5532
4562
see you

[ivconic]

Yes, these two PICs (18F4520 and 18F45K22) are upwards compatible pin-wise, but that's about it. The internal registers and config bits are quite different.
I've been comparing the two datasheets, and also found this migration document -> http://ww1.microchip.com/downloads/e...doc/39647a.pdf
The 18F45K20 is much more complicated than this project requires.

The 18F4520 ADCs are enabled in sequential blocks using ADCON1, whereas the 18F45K22 uses ADCON1 to set the positive and negative voltage references. The ADCs can also be enabled/disabled individually using the ANSEL registers (ANSELA to ANSELE).
The T0CON register appears to be unchanged, but T1CON is quite different. Timer1 has many more features than the the 18F4520.
I'm not certain from the datasheet, but it looks like writing to EEPROM is also affected.

I think there are too many differences between the two to just compile this blindly and hope for the best.

Sadly true, proved in practice.
I was keeping this older post on my mind whole night long, last night.