Voodoo Main Discussion

[SilverSurfer17]

i have a rgb lcd and want to add functions to the menu to change the color hopefully with the pwm if its not used for something else and dont want the extra buttons on the case ill leave connected with switches for now to change the color any chance you can see if this possible with this project ?

[SilverSurfer17]

Never mind i see i need pins 16 and 17 the pwm pins and the screen shot i have has that part cut off so i have to go find a clear shot of all the pins and see if thats connected to anything or being used then figure out how it uses 3 wires but only 2 pins to control 3 different led colors learn the lcd library and make up some new symbols

[SilverSurfer17]

Hey George i have a question i have a rgb 16x2 lcd and i had it wired wrong its a 18 pin and 16 17 and 18 are the 3 led lights they can be controlled by microcontrollers its controlled by negative side anyway of wiring it where it will work with this microcontroller to change colors instead of using switches for each color this is how it get wired to a adrino i know its not a 5 minute project just wondering if its possible without adding more pcb and parts

[SilverSurfer17]

Thats a good idea ill do that when i replace the rest of them thanks

[MartinB]

Ok updated my pic nice work finding that Martin and awesome job coming up with a fast fix George i flipped my screen around and fixed a few of thin test points that keep breaking and that wrong resistor i pulled out just waiting for the right one to move ahead

The best way to make a robust test point is to bend the top portion of a header pin into a hook using snipe nosed pliers prior to soldering into your board

[SilverSurfer17]

Ok updated my pic nice work finding that Martin and awesome job coming up with a fast fix George i flipped my screen around and fixed a few of thin test points that keep breaking and that wrong resistor i pulled out just waiting for the right one to move ahead

[MartinB]

Whenever you find a microcontroller locking up or crashing, it's usually one of three things:
1. A variable has been set to an arithmetic type that is too small to contain the maximum value.
2. The interrupt routine has lost its way,
3. There's an obscure calculation error somewhere.

I managed to rule out #1 fairly quickly, and couldn't see any obvious problem associated with the interrupt routine. If the problem was #3, then it was definitely going to be an obscure one.

Next I added some debug code to write the calculated timer contents to EEPROM after the user exits the menu routine. Examining the EEPROM contents with the PICkit did not reveal any errors, so the routines that calculate the timer contents were definitely working correctly.

At this point I went away to contemplate the issue. Then it struck me ...

Adding up the various pulse widths and delays: 180us + 41us + 60us + 650us +60us = 991us.
Since the pulse period is 1000us, this only leaves 9us for state 5 of the interrupt routine to complete its task, and a minimum of 10us is required.
Clearly the EFE delay is too long at 650us. Reducing the delay to 400us fixed the problem.

Software version V1.1 is now available in post #1 (mikroC project, C code, and hex file).
I also took the opportunity to increase the maximum TX pulse width to 200us, and reduce the minimum main sample delay to 10us.
The debug code has not been removed, but I'll most likely remove it in any future update.

Please download and install the new hex, and let me know if you encounter any problems.

Hi George
I take my hat off to you

[Qiaozhi]

Whenever you find a microcontroller locking up or crashing, it's usually one of three things:
1. A variable has been set to an arithmetic type that is too small to contain the maximum value.
2. The interrupt routine has lost its way,
3. There's an obscure calculation error somewhere.

I managed to rule out #1 fairly quickly, and couldn't see any obvious problem associated with the interrupt routine. If the problem was #3, then it was definitely going to be an obscure one.

Next I added some debug code to write the calculated timer contents to EEPROM after the user exits the menu routine. Examining the EEPROM contents with the PICkit did not reveal any errors, so the routines that calculate the timer contents were definitely working correctly.

At this point I went away to contemplate the issue. Then it struck me ...

Adding up the various pulse widths and delays: 180us + 41us + 60us + 650us +60us = 991us.
Since the pulse period is 1000us, this only leaves 9us for state 5 of the interrupt routine to complete its task, and a minimum of 10us is required.
Clearly the EFE delay is too long at 650us. Reducing the delay to 400us fixed the problem.

Software version V1.1 is now available in post #1 (mikroC project, C code, and hex file).
I also took the opportunity to increase the maximum TX pulse width to 200us, and reduce the minimum main sample delay to 10us.
The debug code has not been removed, but I'll most likely remove it in any future update.

Please download and install the new hex, and let me know if you encounter any problems.

[MartinB]

The settings that were different to the defaults were:
Pulse mode
PI threshold = 2
TX pulse width = 180us
Main sample delay = 49us
Number of PI readings to average = 40

The DISC settings are irrelevant as the detector is set to pulse mode.

I set my Voodoo detector to the same settings ... and it locked up.
After re-flashing the PIC I did some experimentation with the settings. It appears that there's some strange interaction between the TX pulse width and the main sample delay. This only occurs when the TX pulse width is set to 180us and the main sample delay is above 40us. All other combinations seem to be ok.

Now to figure out what's causing it .....

Hi George
I didn't intend to break it, but better on the bench rather than in the middle of a field.
Will reload my PIC and carry on with coil development.
I am sure you will let us know when you have sorted the code.
Thanks for your help and the time you are about to spend on this issue

[Qiaozhi]

Hi George
finally up and running with the PICKit3
The attached image shows the contents of the EEPROM.[ATTACH]54372[/ATTACH]

The settings that were different to the defaults were:
Pulse mode
PI threshold = 2
TX pulse width = 180us
Main sample delay = 49us
Number of PI readings to average = 40

The DISC settings are irrelevant as the detector is set to pulse mode.

I set my Voodoo detector to the same settings ... and it locked up.
After re-flashing the PIC I did some experimentation with the settings. It appears that there's some strange interaction between the TX pulse width and the main sample delay. This only occurs when the TX pulse width is set to 180us and the main sample delay is above 40us. All other combinations seem to be ok.

Now to figure out what's causing it .....

[SilverSurfer17]

I see what you where talking about George with the inductance going up with tighter coils I thought you meant circumference not vertical and I didn?t take that into account with my coil and it going up after wrapping it I was trying to build it for coin shooting but I think it might be to high now so I might be redoing it Thanks Carol for the help you gave others for them to write that article with Tesla coils they use permeant forms the primary coil is 1/2 inch spaced and the secondary is on a tube those knitting forms look nice for winding all kinds of coils

[SilverSurfer17]

I desoldered the bucking coil and had just the tx loop and 1uf cap connected in that pic thinking that was a mono coil ill go check out how to make one so i can use it for testing after i get the resistor so i can eliminate the coil as a problem also until i figure out what im doing

[SilverSurfer17]

I disconnected it to remove the rx circuit as a possible problem I'm following post 277 and I'm only concentrating on the pi circuit until i get it working correctly

[SilverSurfer17]

Ok i have the correct resistor ordered hopefully with that it will show the correct waveform and i can get past this roadblock ill work on these coils i guess until it gets here thanks again for the help Surf and George !

[surfdetector]

No capacitor just the coil and the jig ?

Post #277 has the steps in correct order for the build of the project.