PICKINI V4 - an easy to build, self adjusting PI detector

[useus]

I had not noticed your attachment = audio file yet.
When listening to it, this sounds like the coil error sound. If you connect a headphone to the audio output, you will here a much lower intermittent tone than the one generated by the beeper.
Can you switch the detector on without the coil connected. It should give the same error sound then.
If that is the case, something is wrong with the TX side.

EDIT:
I just tested the coil error sound and this is a continuous low frequency sound.
Not intermittent like in your audio file.

After power on, you first hear the welcome sound.
Then a calibration procedure start during which you hear the 0.5 Hz confidence tick.
When calibration is finished, there is a start sound.
Then, the confidence tick - or detection sound can be heard.

Can you try with a regular headphone first.
If that is OK, connect the 5V beeper to pin 7 of the PIC.
This will not offer all tone varieties as with the headphone output, just a target detection.

sorry, I made a mistake, I connected it to pin 11, connecting it to pin7 remains mute during calibration (it's not a problem), then it works correctly in both motion and non-motion.

My mistake during the assembly of the PCB, sorry again and thanks for the help

[Toros]

There is a problem, forum members, with this device. The problem is that the sensitivity begins to decrease gradually on its own, even though the battery is still fully charged. Does anyone here explain the problem to us?

If you look at the detector circuit, you will immediately see what is the reason for the decrease in the detector's sensitivity. The circuit is powered by 12 volts of voltage, but there is no voltage stabilizer. You say that the battery is still charged, but this is not exactly the case. When the detector consumes 130 mA, the battery voltage constantly drops, which leads to weaker signals compared to those from a few minutes ago. To compensate, you need to increase the sensitivity, which means increasing the consumption again. And so things move in a closed circle. If you looked at the first detector circuits, those with the PIC 16F616, you will notice that there was a 12 volt voltage stabilizer provided. Due to the high consumption of the detector, this stabilizer quickly heated up and the heat had to be removed with a radiator. As far as I remember, someone on the forum suggested removing the stabilizer and supplying power to the circuit directly. In subsequent schemes, this stabilizer was dropped and the problem of reducing sensitivity remained.

[F117]

To compensate, you need to increase the sensitivity, which means increasing the consumption again

Increasing the sensitivity only results in accumulating more temporal measurements in software ( flyback pulse widths).
It does not change the pulse width, nor the pulse frequency. Hence, power consumption remains the same regardless of the sensitivity setting.

[mc_307]

Hello my friend. Is there a sprint layout file for pickini v4.1? Also, is it enough to load the file named "Hex for Pickini4.1 - initial comparator offset value read from EEPROM = faster calibration" in the software section? I will load it with pickit2, can you give me an instruction to follow?

[F117]

I don't have a Sprint layout, only an Eagle layout used at the time.
There are some references in the thread to Sprint - maybe some other forum member has a Sprint layout
https://www.geotech1.com/forums/foru...745#post224745

The hex file to use is indeed this one:
https://www.willaert.world/MD/softwa...Pickini4.1.hex

I used PicKit3 to program the device, but there is a remark from Qiaozhi here that should make it possible to also use PicKit2:
https://www.geotech1.com/forums/foru...189#post224189

There is also a reference to PicKit2 here:
https://www.geotech1.com/forums/foru...008#post225008

[Toros]

Anyone who doesn't have Sprint Layout can download it from here.
https://yadi.sk/d/SYFxFJd9gy5BA
The link is old, but it still works. Click on the arrow. Free.
https://disk.yandex.ru/d/BVyhF3eVj5y8Y

[mc_307]

I don't have a Sprint layout, only an Eagle layout used at the time.
There are some references in the thread to Sprint - maybe some other forum member has a Sprint layout
https://www.geotech1.com/forums/foru...745#post224745

The hex file to use is indeed this one:
https://www.willaert.world/MD/softwa...Pickini4.1.hex

I used PicKit3 to program the device, but there is a remark from Qiaozhi here that should make it possible to also use PicKit2:
https://www.geotech1.com/forums/foru...189#post224189

There is also a reference to PicKit2 here:
https://www.geotech1.com/forums/foru...008#post225008

Thank you. I was confused when there were many options in the software section. I think uploading a single file is enough. Can additions be made to the software? For example, a ferro-nonferro LED indicator? I also saw a video on Youtube, he made a pinpointer with a coil removed from an old CRT TV and the distance was very good. Do you have any information on this?

[Olly]

More than a year ago I did a tiny SMD version of the board, today I finally got around to building and testing it.


It's only 50mm x 30mm.
Here it is next to a Pound Coin.
Works great with V4.2 of the hex file.

Thanks for a great design Bernard.

[Altra]

Nice job! You should put it in a tube and make a walking stick metal detector.

[mc_307]

More than a year ago I did a tiny SMD version of the board, today I finally got around to building and testing it.


It's only 50mm x 30mm.
Here it is next to a Pound Coin.
Works great with V4.2 of the hex file.

Thanks for a great design Bernard.

Hello, is there any documentation for pcb? Thank you.

[Olly]

Here is the documentation package of the board. The PCB is 4 layers which I had made at JLC PCB for $28 for 5 boards.
Please note that the 470 Ohm resistor R4 must be replaced by 2 x 1K 0805 resistors soldered on top of each other as the single 0805 470 R resistor is incapable of handling the power and fails...

Pickini_V4_Refactored.zip


I also kept the PIC as a DIP device for ease of reprogramming.

Kind regards

[MartinB]

Hi Olly,

Thanks for the info. Looks really exciting.

5 boards cost me £3.91 including shipping from JCLPCB so not sure why yours were so expensive.

[Olly]

Yeah, my board cost was very low too, the price I mentioned was with shipping by DHL included.

[MartinB]

Yeah, my board cost was very low too, the price I mentioned was with shipping by DHL included.

That explains it. I always go for the cheapest shipping option and generally receive my boards in 6 to 10 days.