What is this?

[ivconic]

This was found in a park, somebody lost it.
When switched ON; led start to blinks.
There is a kind of printed coil (antena) on it.
I treid to "sniff" it with frequency meter, ham radio, SDR radio, oscilloscope... no sucess.
Some kind of tag. Emitting something. Probably in a short bursts.
WTF!

[kt315]

took this from shop trash box. thinking one is a charge for headsets, second is from water air bubbles pyramid, its glass is broken.
a lipo is not charged.
there is still a compressor like used in aquariums.

[kt315]

'Eternal Batt'. the KT315 Perpetuum Mobile.

i bought 2*AA holders on a-express. did set in wall clocks. now two trash batts works like one good new. no need to buy new batts and waste a money.
i can take trash batts by tons in shops' cycling trash box.

[waltr]

What chip is on it?

[ivconic]

What chip is on it?

It is tough to decipher it, tough to recognize the writings.
I tried with glasses, than added magnifying one, no use.
Than i tried with desktop microscope camera and it's the best that can be done:

[ivconic]

At various angles and with light from the side... I think the inscription is slowly showing, it looks like a PIC12(L)F1501 or something similar.

[ivconic]

Simple schematic:

[kt315]

there is significant limit for similar chip in frequency. anyway you must get harmonics in VHF range. if it works.

[Carl-NC]

Is there an output signal on pin 7? It's curious that the two antennae are in opposite directions.

[waltr]

A PIC12F1501 does have an NCO (numerically controlled oscillator) but also has many other features that it is very hard to determine what it might be programmed to do.
Pin 7 can not have the NCO output.
Features on pin 7 are:
AN0, DACOUT1, A1IN+, CWG1B, CLC2IN1, PWM2, IOC.

Maybe pin 7 is an input.

Yes, the antenna configuration is interesting.
What would be be sensing? An un-balance?

[Riss]

When an inscription on a chip is difficult to read : you spread thin layer smear Thermally conductive silicone paste ( white ) . Rub the paste with your finger - a very thin layer remains . So the inscription is much easier to read . On a prototype board mount green, yellow, red and violet LED ( very bright ) . Usually on the light of a yellow (or green )LED the inscriptions are easy to read . My magnifying glass is from an old one slide projector- about 3.5 cm diameter. With it, you can easily see 3 microns wide gap ( crevice ) of a tape recorder head (with good lighting and an appropriate angle ) .

[Skippy]

I found this 'dual arm square spiral' antenna online:
https://www.researchgate.net/figure/...fig4_331938812

But it seems a bit high-frequency.

[kt315]

915-MHz (UHF band)

No no. it is not be in UHF band, must be lower. for example RFID contours in protection steal box attached on some expensive products (alcohol bottles)
has 1mHz and 400kHz frequencies. receiver is set right at input somewhere, i hear loud sound if i bring their RFID through.
a security noticed that and seems did remember me, so some time i was 'under control'. he walked around me.

[ivconic]

Is there an output signal on pin 7? It's curious that the two antennae are in opposite directions.

I will have to check with oscilloscope.
Video comes soon.

[ivconic]

A PIC12F1501 does have an NCO (numerically controlled oscillator) but also has many other features that it is very hard to determine what it might be programmed to do.
Pin 7 can not have the NCO output.
Features on pin 7 are:
AN0, DACOUT1, A1IN+, CWG1B, CLC2IN1, PWM2, IOC.

Maybe pin 7 is an input.

Yes, the antenna configuration is interesting.
What would be be sensing? An un-balance?

Now i am 100% sure it is PIC12F1501.
Reading Riss's post i checked it again by applied white hand pomade and the writing became clearer.
100% sure it is 12F1501.