My Pulse Oscillation detector project.

[waltr]

i buied this kit. i try a different coil of 18cm (7 inches) whit different uH (250-285-360 and 433) but it find a coin near 5cm (2 inches)...why?? i readed on digiwood internet site that this kit work correctly whit coil from 150 to 400uH...

What does the signal from coil to PIC look like on an O'scope?
It should match the scope pictures Teemo published on his web site.

[gando]

What does the signal from coil to PIC look like on an O'scope?
It should match the scope pictures Teemo published on his web site.

i haven’t oscilloscope for misure or test.
my coils work very well on Russian PI, Surf pi, clone pi avr, but on digiwood kit i have a very poor performance

[h9361]

What does the signal from coil to PIC look like on an O'scope?
It should match the scope pictures Teemo published on his web site.

Hello
Dear Walter.
Is it possible to share me your hex file, PCB and part list?
Thanks

[waltr]

Hello
Dear Walter.
Is it possible to share me your hex file, PCB and part list?
Thanks

I did point to point wiring on a perf board, not PCB.
The hex file is on Teemo's web site and in post #10.
See post #26 for PIC data sheet.
Source code in post #32.
Firmware v1.26 in post #64

I see I use v1.80 code and this doesn't seem to be posted.
Teemos_metaldetector_hex.zip
Teemos_firmware180.zip

[MikesMetal]

I built this from a kit I got from Teemo just over a year ago. I made a 25 turn Spidercoil O/D 22cm and 6cm I/D. I used 1mm speaker wire with a total O/D of 3cm. resistance was about 1 Ohm no idea about the inductance but it worked. Detection depth was very poor, about 5cms for a small gold ring and about 7cms for a 1 Euro coin. All this in free air. Yesterday I unwound the spidercoil and recovered the wire about 14 mtrs. Does anyone else agree with this poor performance? See attached plastic former that I used.

[MikesMetal]

I unwound the coil former and pile wound a 22 cm diameter coil with 30 turns of the same speaker wire. Air tests showed it to be much better, detecting a gold ring at 20cms, a stainless steel watch with stainless strap at about 30cms and a pair of pliers at about 40cms. These tests were done in the 3rd position which seems to be the most sensitive. In the 1st position the ring is clearly detected at about 15cm. I will knock up some sort of support for it and check it on the ground.
Cheers
Mike