Pinpointer with discrimination "Cat-FM" on ATMega328P

[useus]

Ok, but I bought the same passive piezo as the one used and linked by Void118 and I can't get it to work? There are 3 terminals on it. GND, VCC AND I/O. When I connect the GND and VCC to the Cat fm,,,,nothing? Where shoud the I/O be connected please? Regards, Marty.

Vcc on bat+
I/o you need connect this to atmega328 sound pin

[MartyJ1963]

Ok, but I bought the same passive piezo as the one used and linked by Void118 and I can't get it to work? There are 3 terminals on it. GND, VCC AND I/O. When I connect the GND and VCC to the Cat fm,,,,nothing? Where shoud the I/O be connected please? Regards, Marty.

[useus]

Hi Useus. Have you tried this little circuit? It is a Passive piezo driver circuit. The C8550 Can be substituted for BC557. Regards, Marty

You don't need this circuit on cat fm

[MartyJ1963]

Hi Useus. Have you tried this little circuit? It is a Passive piezo driver circuit. The C8550 Can be substituted for BC557. Regards, Marty

[useus]

follow this pattern otherwise you may have the same problems I had



it remains to understand which 33nf capacitor to use, the one I use at the moment is the most stable with temperature changes but I have to find a better one, I have no idea which model to use

[useus]

Watch the video. 1.52 the high-pitched sound without target does it even after turning it on after a minute, it sounds like a loss of power because when I bring it back the target sounds closer than the first time and when it moves away it makes a high-pitched sound.
With 1.2 this problem does not

Test Used two batteries fully charged and psu. Same result every time

https://youtu.be/hKJARVUGyh0

it seems that I have solved the problem, some capacitors need to be replaced and added. there are differences between atmega328p-au and atmega328p-pu regarding power supply.
I will have to redesign the pcb and the scheme, it must be taken into consideration

[Bai Borko]

Hello Bai Borko !!
Nice design, but take void118's advice into account; that the 33n capacitor should be as close to the coil as possible.

CAT.FM.v1.2.1..rar

Hello Ruben,

here is the updated version v1.2.1 with void118's recommendations. It can be placed different sizes 33n capacitor.

Cheers!

[Ruben2000]

Hi Ruben,

i made little changes on your pcb and add 10 pin ISP interface for quick programing of the microcontroller.

cheers!

Hello Bai Borko !!
Nice design, but take void118's advice into account; that the 33n capacitor should be as close to the coil as possible.

[MartyJ1963]

Thanks Useus. Regards, Marty.

[useus]

Hi Useus. What type of 33nf capacitor are you using at the moment? Is it a box capacitor or some other? Thanks, Marty.

CBB

[MartyJ1963]

Hi Useus. What type of 33nf capacitor are you using at the moment? Is it a box capacitor or some other? Thanks, Marty.

[useus]

Are you serious?

Watch the video. 1.52 the high-pitched sound without target does it even after turning it on after a minute, it sounds like a loss of power because when I bring it back the target sounds closer than the first time and when it moves away it makes a high-pitched sound.
With 1.2 this problem does not

Test Used two batteries fully charged and psu. Same result every time

https://youtu.be/hKJARVUGyh0

[useus]

Are you serious?

yes I'm serious, with 1.2 it doesn't sound, with 1.51 it sounds very often and the calibration needs to be redone.


then I did some tests with 33nf capacitors, the green one is not good because it feels too much temperature change so I replaced it. improved with a different capacitor but the problem persists with firmware 1.51. with 1.2 everything ok

[void118]

what you earn you share with me since I'm testing it on the pitch


I went back to firmware 1.2 even if the detection is less, I completely fixed the sound without target and without shielding the coil.


at this point something is wrong with firmware 1.51

Are you serious?

[MartyJ1963]

Thanks Bai, Regards, Marty.