Voodoo Main Discussion

[phred01]

DIYdetector is closed Where can one find Voodoo rev c gerber files be found?

[phred01]

The search for a PI detector that can discriminate against ferrous targets is like "black magic", so I chose "Voodoo".
It was almost called "Chimera", which arguably may have been more appropriate.

Voodoo is PIC-based, and source code is included.
If anyone is interested I can post the Gerber files, and ask Silverdog if he would like to add some PCBs to his online shop.
The design is through-hole to make it easier for DIYers.

Please do post the Gerber files or supply link to download

[phred01]

please repost hex file

[kt315]

DIYdetector is closed Where can one find Voodoo rev c gerber files be found?

you have to learn the forum deeply, IMHO The Voodoo Project - Published October 2020 - Geotech Forums (geotech1.com)

[Qiaozhi]

Hi all
Just become aware of this interesting project. Without having a batch of PCBs to be made has anyone one got for sale?

Which country do you live in?

[phred01]

Which country do you live in?

Australia

[phred01]

thanx for the link

[SeanS]

After reading the contents of this forum with such a wealth of information with such friendly and supportive users for weeks and learning about various MD technologies, I have just encountered this amazing project, thank you Qiaozhi.

Having made my first prototype of Hammerhead version D on a home PCB which performs amazingly in air testing, thank you, Carl, yet to be tested in the wild, I was wondering if anyone had a couple of PCBs for the Voodoo. I am in the UK.

Thank you all,
Sean

[Qiaozhi]

After reading the contents of this forum with such a wealth of information with such friendly and supportive users for weeks and learning about various MD technologies, I have just encountered this amazing project, thank you Qiaozhi.

Having made my first prototype of Hammerhead version D on a home PCB which performs amazingly in air testing, thank you, Carl, yet to be tested in the wild, I was wondering if anyone had a couple of PCBs for the Voodoo. I am in the UK.

Thank you all,
Sean

I'm also in the UK, and I have a couple of spare blank Voodoo REV-C PCBs. One of them has a 40-pin socket for the PIC soldered in place.
Send me a PM.

[phred01]

Thanx for the offer Have ordered boards from JLCPCB very easy to order & @ a very reasonable cost incl shipping 5 boards will be more than enough to build some detectors Will post my experience and modifications that I plan

[kt315]

I'm also in the UK, and I have a couple of spare blank Voodoo REV-C PCBs. One of them has a 40-pin socket for the PIC soldered in place.
Send me a PM.

does this PIC have a SMD, 'bug', hull?

[phred01]

Other than fragmented circuits in the book is there a complete schematic on one sheet

[Qiaozhi]

Other than fragmented circuits in the book is there a complete schematic on one sheet

There is no complete "one sheet" schematic available.

[phred01]

Getting all the bits together On page 40 of the book there is a pix of the display with buttons a housing on a goose neck were can buy this or is there a STL file to print it up?

[Gunghouk]

Voodoo is 100% George.



This is generally true. In the case of a Voodoo, the ADC is sampling relatively slow signals so I doubt the sampling jitter will make a big difference. I don't recall the processing loop rate of Voodoo so I can't say for sure.

My personal preference is to run the ADC at a specific sample rate (say, 5ms) and use the data ready to trigger an interrupt, whereby this sets the loop rate of the software. But then, I also run the timers for the TX & demods autonomously. Voodoo uses a low-end PIC micro so it is pretty limited for doing stuff like this.

Hi Carl, I have been able to utilize the limited capability of the pic and eliminate(?) jitter while increasing overall speed and averaging accuracy as previously outlined.
I intend to make available soon a new version XC3.00 with these improvements, for testing by anyone interested with a functioning Voodoo detector.

All changes very verified on a Rigol
DHO 814, four channel oscilloscope.

The change details are :

***
XC3.0 (Neil Jolliff, aka Gunghouk)

DSP routine call moved to interrupt service routine to improve signal averaging, reduce main loop time and
Improve loop time consistency thereby reducing jitter.
DSP only runs every 1mS Timer1 call to ISR not on pulse timer0 ISR calls.

NOTE: This change enures consistent pulse timing regardless of any future code changes affecting main loop
execution time eg. UI mods.
Will probably improve detector response times and allow reduction in averaging sizes.

PI sampled on high sync pulse, Disc sampled on low sync pulse regardless of mode. This helps with DSP code speed
consistancy.

Timer value calculations simplified to ease understanding.
Disc pulse delay, after TX pulse, offset value added.

All timer offsets changed to suit above modifications.

Timing routine rationalised to reduce ISR run time helping to eliminate jitter.

Battery averaging changed to 1024 samples due main loop speed increase affecting battery display jitter.

Slight increases in LCD data delay times in order to eliminate occasional display artifacts occurring on 4x20
display.

PI oscillator frequency in common.h changed to 20Mhz

***
Future mods(?)
Single rotary encoder control instead of 4 buttons.
4x20 lcd or graphic display

***

Why bother you might ask.....

1. Because I am an engineer (albeit recently retired) and have nothing but time on my hands.
2. To keep learning new things (PICs & programming) and to refresh long ago forgotten or barely used skills (C programming)
3. Because I can and love doing it.
4. Fear of mushy retirement brain syndrome.

Regards to all

Neil