Brutkey

Helge Wurst
@MisterHW@fosstodon.org

@RueNahcMohr@infosec.exchange okay, but in more practical news:

when those 128x32 OLEDs became popular some 10 years ago, a friend and I strapped one to a pen, ESP8266 and sm0l battery.

We got to the point where the display would show a datamatrix code encoding local measurements. We should have used something with a better finder pattern, but the idea was to add 6 DoF tracking, and then one would scribble across a PCB with an H field / E field probe stylus and image analysis software would reconstruct that.

Helge Wurst
@MisterHW@fosstodon.org

@RueNahcMohr@infosec.exchange I still think it's a cool idea, since you could basically even capture waveforms, analyze them and then 3D plot the spatial distribution of fields and spectal components of noise from DC to RF.

Someone should finally steal that idea and make it happen :)
And probably there are also better ways to do the tracking (e.g. sub-mm UWB + IMU?)

Helge Wurst
@MisterHW@fosstodon.org

Static fields can be measured with a field mill as illustrated below. I was reminded of condenser mics with their fragile little MOSFETs as far as AC detection goes. With proper bias, suitable MOSFET an a hatched zone on a 1-layer PET PCB acting as the sense electrode, it should be possible to pick up AC components of the electric field.

Charge detection will be limited to low frequency AC, but I imagine it to be usable.