'KROT2-XM' (mole), new project Xmega32

[WM6]

Thanks for photo. Nice design. But I am asking for structure of your coil cable. I wish to see photo like this:

[SimonS]

I did't finish my coil yet. Waiting for shell! For this cable I'll use sensor cable. It is like USB cable, but much stronger and flexibility. 4.wire+shield.
I'll use 2. cable. One for TX on for RX

[WM6]

Ok then you can wire your coil according schematic in my post Nr.127:



Coil shielding should be connected to RX ground.

If you use two wire microphone cable (both wire separate shielded), then coil shielding should be connected to RX ground
and TX shielding used as backward wire (isolated from coil shielding) to TX ground.

[Geo]

Hey and what about this unstable erratic noisess only Geo has it ? Is this md stable outdoor?
Regards

Erratic signals remains, so today i constructed a new pcb and i"ll try to make another one KPOT-2. If it will work without erratic signals.. ok, else the Hammer!!!

[reiv]

Ok, good to know, wish You luck and waiting for your replay

[SimonS]

Today I made my first coil. Hope it is everything OK. I use sinus wave generator at 8.5kHz for nulling. At final I got 0.000VAC
Just before I put over epoxy glue I ask you it is OK like I do this?

[WM6]

Good work Simon, congratulations.

Seems except coils shielding. Shielding should be made with small gap and not in closed circle.

Like this:



Additionally, author last suggestion was to best tune coil at 8kHz.

[SimonS]

Thanks!
Yes, I coil shell do have gap. Only photos are low quality (phone..)

At author page I read, that tune must me done obout 8.5kHz (8-9kHz). OK this is not problem to change.
thanks for your comment

[WM6]

Well done!

Probably authors frequency recommendation changes with last version of software code, but 8.5kHz should be OK too.

[SimonS]

Today I connect coil with detector. Now I have problem.
TX error 1500mA
I look gain at menu when I disconnect coil is 90mA with coil is 1500mA. Good thing is, that I did't put in epoxy yet. I try to move wite but is only worse. What do I do wrong? I do wire exectly as is write on site

[Jose]

Today I connect coil with detector. Now I have problem.
TX error 1500mA
I look gain at menu when I disconnect coil is 90mA with coil is 1500mA. Good thing is, that I did't put in epoxy yet. I try to move wite but is only worse. What do I do wrong? I do wire exectly as is write on site

[SimonS]

I do as you show. I disconnect grounded, but nothing better.
Same valute of error

[Geo]

Who is the DC resistance of Tx coil??? Maybe you have a short with the foil.

[SimonS]

I have some ghost here!
I take my oscilloscope and now I don't understand nothing !
I put sond of my scope on RX and look what happen on LCD. When I put coil in null (on scope 0.00V) I see on LCD 2000mV when I put wings of coil out of null at my scope 1V I got on LCD 1660mV. Out of logic....
If I shortcut RX I got on scope 0.00V and on LCD 27mV
So there is nothing wrong with my search coil (I think)
RX freq. is 8547Hz and 98mA what is look OK?
I check component around AD8091 and it look everything OK. I use Z80 board

[SimonS]

Today I take some time and what do I see. Look at attach video.
BLUE signal is output of AD8091 pin.6
YELOW is signal at sond (RX coil)
Like you can see on video signal that I got at RX in at minimum 50mV-PP. I cannot go lower? Is this normal? Why feedback on pin.2 don't eliminate this error? (at menu Zero-Adc) I use v.06A version of program