I wired up an MSGEQ7 according to this tutorial:
http://skoba.no-ip.org/msgeq7/And I connected the line-level output from my computer to it directly.
At first I wasn't getting any results, every frequency band just read ~50 no matter what was playing. At some point I accidentally removed the ground connection between the chip and the Arduino (I had ground on the diagram connected to GND on the Arduino), and it started working perfectly. It seemed strange to me that I could power the circuit using the +5V from the Arduino without using the GND pin, but the numbers I'm getting back match the music really well.
So I have a couple of questions:
- How is it that it can work this way?
- What might I be doing wrong such that it doesn't work the way it's shown on the site?
- Is it ok to keep using it like this, or can I expect unusual behavior?
Thanks so much,
Toby