I'm playing around with an oscilloscope and my laptop's headphone jack. I get the tip/ring/ground and measure between them. I also measure between them and an external reference ground. I notice I can see when the battery is charging. That is, if the battery is not in the laptop but the AC is in, then I insert the battery, it runs through some software or something in the battery for a few seconds and then if the battery is not full, it goes to a waveform - if it is full, it goes to another "quieter" waveform.
I am just doing this for fun. Can anyone think of interesting experiments I can do? I would like to see about extracting signal from the noise of the waveform.
Might there be any data present in the signal on the headphone jack if I am not putting out an audio waveform? ie. by virtue of the circuit passing through some of the data processing elements of the motherboard.
For instance in a way similar to the paper published here:
https://www.defcon.org/images/defcon...strokes-wp.pdf
or
http://cs.tau.ac.il/~tromer/acoustic/ (Here the noise comes from a bank of 1500µF capacitors).
I am just doing this for fun. Can anyone think of interesting experiments I can do? I would like to see about extracting signal from the noise of the waveform.
Might there be any data present in the signal on the headphone jack if I am not putting out an audio waveform? ie. by virtue of the circuit passing through some of the data processing elements of the motherboard.
For instance in a way similar to the paper published here:
https://www.defcon.org/images/defcon...strokes-wp.pdf
or
http://cs.tau.ac.il/~tromer/acoustic/ (Here the noise comes from a bank of 1500µF capacitors).
