Voodoo Main Discussion

[SilverSurfer17]

No i never checked each part individually ive never had to in the past but then again i assembled and tested not had to fix boards so i can figure some things out i barely even know how to use this oscilloscope lol

[green]

Totally agree... I have been preaching that for 3+ years. Twelve bits simply just do not cut it!

Is 22 bit A-D, no amplifier better than 12 bit AD with a fast low noise amplifier gain=1000? If yes, why?

[SilverSurfer17]

All the wave form diagrams is that with a damping resistor and coil attached ? Or can i remove the coil and just use the jig and concentrate just on the board until my waves forms match the book ?

[surfdetector]

Here is what the output of tx is with jig installed and the prob on pos and negative on neg and channel 2 on tp2

I recommend that you perform some oscilloscope probe compensation.
https://youtu.be/CzFzqGawmvU

[KingJL]

Is 22 bit A-D, no amplifier better than 12 bit AD with a fast low noise amplifier gain=1000? If yes, why?

Quite simply "dynamic range". The "gain = 1000" should say it all! But you can't have a 22 bit ADC and no amplifier either... But you can have a 22 bit ADC and a amp with a gain < 10 with a nyquist filter.

[Qiaozhi]

Or can i remove the coil and just use the jig ... ?

[eclipse]

OK I've misunderstood the goals here. I thought we are talking more about proof of concept design.
You guys shoot for high performance top of range etc.
Yes a 50$ ADC is a sweet thing to have, if you have already covered the basic goals of your design and you're limited by MCU performance.
I'm doing a ADC/PWM with the PIC32MZ (which uses a 12Bit ADC) and it's not all that great but I can live with it for now, and I can focus on the rest of the design.

BTW I don't digitize the analog signal so ADC accuracy shouldn't alter the performance /like on the voodoo there/. I simply use it to vary the tone of the PWM so ADC accuracy is no big deal.

Why all this? Simply I've read the book and got inspired to pursue similar goals like the voodoo project /it's just proof of concept design/

[Qiaozhi]

OK I've misunderstood the goals here. I thought we are talking more about proof of concept design.
You guys shoot for high performance top of range etc.
Yes a 50$ ADC is a sweet thing to have, if you have already covered the basic goals of your design and you're limited by MCU performance.
I'm doing a ADC/PWM with the PIC32MZ (which uses a 12Bit ADC) and it's not all that great but I can live with it for now, and I can focus on the rest of the design.

BTW I don't digitize the analog signal so ADC accuracy shouldn't alter the performance /like on the voodoo there/. I simply use it to vary the tone of the PWM so ADC accuracy is no big deal.

Why all this? Simply I've read the book and got inspired to pursue similar goals like the voodoo project /it's just proof of concept design/

At least someone gets it.

[Matt_Rowe]

I don't want to have to buy 15 different ohm values for it if there is a way with the jig to know the exact ohm value of what it needs from what ive seen those type resistors aren't cheap i knew i would have problems with the tuning part i didn't think as much building the board ill check all the values later on the resistors to make sure they are what they are suppose to be

Look at surfdetectors video on how to use the jig

[Matt_Rowe]

No i never checked each part individually ive never had to in the past but then again i assembled and tested not had to fix boards so i can figure some things out i barely even know how to use this oscilloscope lol

Did you check each step as you built the board, if not, how do you know you dont have a new faulty part

[Matt_Rowe]

No i never checked each part individually ive never had to in the past but then again i assembled and tested not had to fix boards so i can figure some things out i barely even know how to use this oscilloscope lol

I have only seen scopes and never used one, so i got one for free, and the first thing i did was download the manual, looked up how to set it up and basic use, then watched a couple vids on you tube about scopes, how to use, set up, do a simple square wave, and make sure ho w to hook up probes and especially about the ground on the probe and when not to hook it up, and where to hook it up.

[SilverSurfer17]

Ok back to where i was at the start no tx coil connected and only the jig connected to the tx channel and its the same as it was before using the ac to dc power supply but it looks backward still even using dc

[Matt_Rowe]

[ATTACH]54563[/ATTACH]Ok back to where i was at the start no tx coil connected and only the jig connected to the tx channel and its the same as it was before using the ac to dc power supply but it looks backward still even using dc

pages 28 to 32 in the book maybe will help, not sure

[SilverSurfer17]

Ok surf thanks that was part of the problem plus i had the prob on backwards on the resistor jig now it looks just like yours did in the video so the transmit portion works now what this is where im running into trouble checking it with a mono coil it doesnt beep it doesnt look right for the wave forms but sometimes i can see the wave move when i run metal by the loop

[SilverSurfer17]

how do i flip this around to look like in the book that looks like 90% of the battle ?