I needed a way to compare two signals on an engine control unit project I’m working on. I’ve only got a very cheap and basic single channel digital oscilloscope so I couldn’t use that to compare them.
So, I though I could probably use a pair of headphones to feed a signal into each ear, and I would perhaps be able to hear the difference. This actually worked pretty well. I suppose if you’ve got some of those mad 7.1 channel headphones then you can have 7.1 oscilloscope channels!
This will probably only work well for fairly low frequency signals, I’m in the low kHz range at the moment. You can’t really take measurements or see the shape of the signal (although different shapes will have different sounds), and it probably only works for comparing two signals to hear if they’re the same. I don’t think you’ll be able to detect phase difference either. Also, I’m not sure that driving the headphones directly from the microcontrollers this way is completely safe.
Here’s a guide to this highly complex procedure
- Chop off a few centimeters of single core wire
- Pull the insulation off of it
- Wrap it around your headphone jack
- Repeat three times and stick each loop into some breadboard
Pull the insulation off of some single core wire
Wrap single core wire around headphone plug
Use one ear per channel