Voodoo Main Discussion

[lamoiz]

Hi Lamoiz,

what pre amp are you using?
That doesnt look like a 5532.
Testing on the voodoo with a fast coil
I've had to damp it back to sample properly since the voodoo only goes to 15 us.
did you try any mono coil tests before disc assembly.
My R2 3r3 is getting hot did you have this Issue?

Has anyone had this issue?

Thanks

hi godigit, yes it is a mono coil that made a few years ago, and that I usually use on the mpp. On the picture it is on the voodoo, behind the original pream, ..

[6666]

Hey guys just watch out for the value of R6, it is one ohm
the schematic printing in the book looks like part of a 3 but its a 1


And the value of R2 is 3.3 ohms (3R3) two watts, I dont have any two watt resistors so made it from two resistors
a one watt 2.2 ohm and a one watt 1 ohm, easy peasy.

[godigit1]

So far, I have not had any excessive heat on my project. What wattage resistor are you using?

Hey surfdetector,

it was a two watt resistor, I think I figured out what happened at least I hope so.
Ill figure it out here pretty soon as Im going ahead with the disc portions of the build.

I had wired my coil like a Mono on the MPP and didn't have the disc portion built so I think somehow I was overloading The R2 resistor.
strange though I had detection and the coil was damping.

I like the sound of the Voodoo.

[godigit1]

hi godigit, yes it is a mono coil that made a few years ago, and that I usually use on the mpp. On the picture it is on the voodoo, behind the original pream, ..

Hi lamoiz
Thanks that looks like a good coil the pre amp looked like a 412 the way the turn off is but A 5532.
Last I tested I had slower coils I may revisit the 5532 I had given up on it finding the 4562 2 us faster out the door. at the time the 5532 wouldnt go below 8 us for me with the coil tested.
Out of curiosity what is your damping value?
Thanks

[godigit1]

Interesting your coil has low edge sensitivity. My figure8 coil detects almost the same edge distance as centered over one of the Rx coils. Coke can, Rx_(2)133mmID fig8. 24inches centered over one coil, 22inches from the side(same plane). Probably not good.

Hi Green,
I was rereading the thread and missed this post.

I wasn't able to follow completely you new coil build.
Not sure of the size but familiar with your design.
My planar coils have had seems like full edge depth as well I've stopped sitting so close. He he
The coil I've been testing is a dual field with the inner coil shaped like a D and a D Rx coil.

I've been thinking a little more that the edged detection was reduced by the small size of the Rx D coil.
At first I was thinking maybe the Tx outer coil may be running blocker but not so sure.
I'm making two larger Rx d coils to try see what happens.

Be Well.

Oh yea glad you guys got some fishing in.

[lamoiz]

Hi lamoiz
Thanks that looks like a good coil the pre amp looked like a 412 the way the turn off is but A 5532.
Last I tested I had slower coils I may revisit the 5532 I had given up on it finding the 4562 2 us faster out the door. at the time the 5532 wouldnt go below 8 us for me with the coil tested.
Out of curiosity what is your damping value?
Thanks

hi godigit, I did not have overheating of R2 when I connected my mono, this one has a damping resistance of 401ohm, (390 high tolerance ..) when I had done the test with the potentiometer, the value of 410 ohm would have been the best .. but I had that on hand ..

[ivconic]

Moving forward... slowly...

[ivconic]

Bad luck!
Just as i finished all on boards.
I learned now that i can not use damn (now useless to me) "Ready for Pic" dev board to program 18F4520 chips.
18F45K22 which is on the board originally; is having bootloader, that's why it is accepting flashing.
OK, so i tried last option; i put 18F45K22 flashed with Voodoo hex on the pcb.
Not working. Seems some functions are working, like sync signal, since LT1054 (had one!) is working alright, providing voltages.
But nothing on LCD and when both TL072 are in sockets; 5v from 78L05 drops to 0.3v!!??
When i pull out both TL072 and all other chips are on sockets; i get +5.05v alright.
When i put back only one TL072; voltage drops to +4.6v. When put back second TL072; drops to 0.3v!
Same on both pcbs.
When both TL072 pulled out; all the voltages are there. Nothing on LCD.
Although all 4 TL072 (2 pcbs) are brand new, yet i tried several other dual opamps there, just to be sure... same behavior.
So... my conclusion; since both TL072 are directly tied to mcu, and mcu is not 18F4520 but 18F45K22; some conflict happens and voltage drops.
Fortunate situation is that i made 2 pcbs, totally the same. So i can simply rule out any eventual mistake that i made during the soldering process.
Since both pcbs behaving the same.
Bad luck is that right now i don't have tools to program those two empty 18F4520's.
So i'll have to order now PICKIT and wait several days to arrive.
Sheeeeesshhhh!
I have horrible urge to swear now very ugly!

[6666]

Bad luck!
Just as i finished all on boards.
I learned now that i can not use damn (now useless to me) "Ready for Pic" dev board to program 18F4520 chips.
18F45K22 which is on the board originally; is having bootloader, that's why it is accepting flashing.
OK, so i tried last option; i put 18F45K22 flashed with Voodoo hex on the pcb.
Not working. Seems some functions are working, like sync signal, since LT1054 (had one!) is working alright, providing voltages.
But nothing on LCD and when both TL072 are in sockets; 5v from 78L05 drops to 0.3v!!??
When i pull out both TL072 and all other chips are on sockets; i get +5.05v alright.
When i put back only one TL072; voltage drops to +4.6v. When put back second TL072; drops to 0.3v!
Same on both pcbs.
When both TL072 pulled out; all the voltages are there. Nothing on LCD.
Although all 4 TL072 (2 pcbs) are brand new, yet i tried several other dual opamps there, just to be sure... same behavior.
So... my conclusion; since both TL072 are directly tied to mcu, and mcu is not 18F4520 but 18F45K22; some conflict happens and voltage drops.
Fortunate situation is that i made 2 pcbs, totally the same. So i can simply rule out any eventual mistake that i made during the soldering process.
Since both pcbs behaving the same.
Bad luck is that right now i don't have tools to program those two empty 18F4520's.
So i'll have to order now PICKIT and wait several days to arrive.
Sheeeeesshhhh!
I have horrible urge to swear now very ugly!

I hope you get your voodoo working
re programming the 4520, I found something that may help, the 4520 is listed, with you being a arduino wizard it may work for you

https://sites.google.com/site/thehig...arduino-pic18f

a bit more info here




http://pleasantlyclueless.blogspot.c...rogrammer.html

[ivconic]

I hope you get your voodoo working
re programming the 4520, I found something that may help, the 4520 is listed, with you being a arduino wizard it may work for you
https://sites.google.com/site/thehig...arduino-pic18f
a bit more info here
http://pleasantlyclueless.blogspot.c...rogrammer.html

That came to my mind too. But i am already very exhausted for trying various options.
Went to addict and found out my old MBHP_BURNER_V1b which is old and obsolete parallel port programmer.
At the time i used it to program PIC16F876, PIC16F877, PIC16F84, PIC16F628 and 12C508 and 12C509.
That hardware works splendid with PBrennerNG44 and PBrennerNG48 (sprut.de).
But! It can't recognize 18F4520. I took also old laptop from addict, Pentium III, Windows XP, with parallel port.
Wasted several hours to sort those all out, connect all, tried... nothing!
Although somewhere in archives i saw that it should support 18F4520. In reality it does not.
To test if it is still alive after all those years; i put 16F877 and tested, yup; everything is working so smooth.
So, software is not recognizing damn 18F4520.
Than i surfed the net and found out PICPGM with auto detect features. Promising.
Actually total miss. Wrongly auto detects hardware, although leds on hardware kinda flashing somewhat.
Recognizes hardware as some "AN..." programmer. While in essence it is Tait classic programmer, so as it says in PBrenner.
When i manually set it to Tait Classic ... it won't work at all, leds not flashing.
And so on.. and so on... several hours of trying every crazy thing.
So i am very exhausted and tired.
Reading whats on those links i see in advance another several hours wasted, since there is no particular solution for 18F4520.
Now am nowhere. No turning back. Must buy Pickit 3 and wait several days more.
...
Qiaozhi you can help with step by step explanation how to program 18F4520, how you did it.
For us non-PIC users.

[6666]

That came to my mind too. But i am already very exhausted for trying various options.
Went to addict and found out my old MBHP_BURNER_V1b which is old and obsolete parallel port programmer.
At the time i used it to program PIC16F876, PIC16F877, PIC16F84, PIC16F628 and 12C508 and 12C509.
That hardware works splendid with PBrennerNG44 and PBrennerNG48 (sprut.de).
But! It can't recognize 18F4520. I took also old laptop from addict, Pentium III, Windows XP, with parallel port.
Wasted several hours to sort those all out, connect all, tried... nothing!
Although somewhere in archives i saw that it should support 18F4520. In reality it does not.
To test if it is still alive after all those years; i put 16F877 and tested, yup; everything is working so smooth.
So, software is not recognizing damn 18F4520.
Than i surfed the net and found out PICPGM with auto detect features. Promising.
Actually total miss. Wrongly auto detects hardware, although leds on hardware kinda flashing somewhat.
Recognizes hardware as some "AN..." programmer. While in essence it is Tait classic programmer, so as it says in PBrenner.
When i manually set it to Tait Classic ... it won't work at all, leds not flashing.
And so on.. and so on... several hours of trying every crazy thing.
So i am very exhausted and tired.
Reading whats on those links i see in advance another several hours wasted, since there is no particular solution for 18F4520.
Now am nowhere. No turning back. Must buy Pickit 3 and wait several days more.
...
Qiaozhi you can help with step by step explanation how to program 18F4520, how you did it.
For us non-PIC users.

Yes its frustrating sometimes
I can write out the instructions for pickit 3 and MPLAB IDE V8.76, this version of software is a bit older now but it works for all the pics I use

[6666]

Just been doing a burn in test of TX and PI preamp.
Had to make an adapter for the 300 uH coil and RD to make it work, pity that RD is not an option to be soldered on the pcb.
Soldering resistors and capacitors on coil plugs is not my thing.

My made up 3.3 ohm resistor is quite warm at 30'C, ambient air is 20'c, the one ohm is cool, but rest of parts ok SO FAR.
But nice clean signal at preamp out, it even responds to a target, seems to settle after about 10uS
running the circuit on 3 18650's.
so far so good

[lamoiz]

Hi everyone. this week I didn't have much time for the voodoo, but ... I still did the test on a new tx coil, on the super D, the result of all this is that between the wires of silicon and the litz wires, the latter is really good. the litz is faster, the detection distance is much better on smaller targets, so I will take this option for the realization of the final product and do some tests in a real soil!
this is the other, in silicon threads.
see you.

[surfdetector]

...
Qiaozhi you can help with step by step explanation how to program 18F4520, how you did it.
For us non-PIC users.

I am not sure if this is what you need but I did a step by step video of loading the hex file onto the PIC with a PICKit3

https://youtu.be/O9V8fmQWXe4

[Qiaozhi]

I am not sure if this is what you need but I did a step by step video of loading the hex file onto the PIC with a PICKit3

https://youtu.be/O9V8fmQWXe4

Yes, that's it.
I actually used a PICKit4, but both PICKit3 and PICKit2 will work. I've used all three on the PIC18F4520 without any problems.
You can program the PIC directly on the Voodoo board via the ICSP connector, so you don't need the ZIF programming adapter board.