Help to design a PCB for my PI design!

[okantex]

Hi 1843 ,

since you have completed your detector.
what abuot coin test?? can you try few metals and share results with us.
may be a video presentation?

regards
Okantex

[1843]

New Hex

About the trimpots:

R26: Hold S5 and then switch the detector on. Now the detector is in battery adjustment mode and showing a number. Apply your minimum battery voltage (10 to 11V) to it, adjust R26 until the number is around 660.

R12: With a coil connected, temporary short the Base of Q9 to 0V. By adjusting R12 you should have a voltage of about 200mV at the pin6 of U7.

New Hex is attached. I've forgotten to reverse the backlight pulses in the previous revision.

[Vermeer111]

i don´t have an oszilloskope (in the moment) ok i will try 680 ohm with the coil for hammerhead Thank you for your answer

[1843]

ok i have one question,if i use the coil from the hammerhead detector is the damping resistor the same ? (680 ohms) i need this detector for coin relict and jewelery(rings chains etc) excuse my english Thank you

I think a higher value resistor should work. Do you have an oscilloscope? If so try 1K, 820R,...
680R certainly works OK, but not optimum.

[Vermeer111]

ok i have one question,if i use the coil from the hammerhead detector is the damping resistor the same ? (680 ohms) i need this detector for coin relict and jewelery(rings chains etc) excuse my english Thank you

[Rov]

This is a very good project!are the files from Qiaozhi suitable for a pcb manufacturer suitable to make a one off hobby pcb for me,like gerber?What should I do!
I have bought a small quantity of Atmega8 chips an a educational board to experiment an program.I am Looking forward to this ,is very good Project.

[Tinkerer]

I could ... but it may take a long time, due to other commitments.
If you email the design to me, I can pick at it during any spare moments.

Thanks for the kind offer. Time? I have been tinkering a few years with this, I guess as long as I am still tinkering I am still alive.
I will send you a design.

Tinkerer

tp= r12 trim.

r12 trim.= 0 volt

[Qiaozhi]

This is most excellent work.
Could I convince you to design a PCB for a PI metal detector that discriminates?

Tinkerer

I could ... but it may take a long time, due to other commitments.
If you email the design to me, I can pick at it during any spare moments.

[Qiaozhi]

hello i have on question,what dimensions have this pcb board thank you

The board dimensions are 4" x 3.5".
This is slightly wider in the y direction than the Hammerhead PI RevD PCB, which is double-sided.

[1843]

Great!

Hi All,

First of all I apperciate Qiaozhi for his time and efforts. I will send some special pre-programmed Atmega8's to him.


Now anyone can build and use this detector.

About the buttons:
S1. Decreases any parameter present on the LCD.
S2. Increases the parameter.
S3. Selects between various parameters.
S4. Tunes the PI in manual mode.
S5. Shows the battery status for 1 second.

About the coil:
Use a coil the same as the Hammerhad's for detecting coins and rings, and for nugget hunting make a fast coil as bbsailor describes in his article.
The sampling delay is adjustable from 7us to 25us, adjust to fit your coil.

Other settings are easy and you will know them as soon as once you work with.
The Cx is not used in this version. Maybe for later versions if I make.


Best regards,
1843

[Vermeer111]

hello i have on question,what dimensions have this pcb board thank you

[Tinkerer]

PCB

This is most excellent work.
Could I convince you to design a PCB for a PI metal detector that discriminates?

Tinkerer

[Qiaozhi]

Version 2.2

Here's the latest (and hopefully last) update for 1843's PI detector.

Changes made:

1. Swapped over S2 and S3 on schematic.
2. Added Cx across R10 as optional component.
3. Tidied up component placement / silk screen.

[Qiaozhi]

Version 2.1

Updated schematic and PCB.