I am using Arduino UNO and did a project to sync LED to audio. I am not sure how to read a value from a speaker.
I connected a LED to Pin 9 (PWN) with 220ohms and ground. I connected A0 pin to a speaker pin and ground pin the other pin on speaker. I used the Smoothing example of arduino input and modified the code a bit to output to LED. The speaker I used was with an old Phillips Music System and had only two pins. I played the music and led synced perfectly and everything worked fine. The project was a success.
Today I wanted to try to connect to a home theater (5.1 Sony HT-IV300 Model). This speakers also have same 2 pins. So I did everything same. A0 to Speaker pin 1 and Ground to Speaker pin 2. But suddenly the Music System went to power protect mode and A0 is stuck at ~1000 (975 - 977). I connected the arduino again with the Phillips Music System (Same setup) but A0 is always gives ~1000 value. Connecting to A1 and changing the code works perfectly fine!
Where did I go wrong? I cannot understand what happened to A0 pin? What is the correct way to read speaker values?
Thank You. Abhi