SirCmpwn wrote:
Thanks! By alternate, should I have them both on, then both off, or one on, one off, then one off, and one on?
Doesn't make a difference. If you want different frequencies in different ears, the question is moot anyway, because you'll be varying the state in different ears at different rates. I think there may already be a topic on this with more information; lemme look.
Here it is:
http://www.cemetech.net/forum/viewtopic.php?t=4773
KermMartian wrote:
gain enough voltage or something similar, why is that?
So as you correctly noted, the ring and the tip each correspond to one ear of classic headphones. Recall from your basic physics or music class that sound is vibrations of the air. In headphones, vibrations are created by a paper or plastic diaphragm moving back and forth. The faster it vibrates, the higher the note; the slower, the lower. The bigger the amplitude of the vibration (how far it moves from neutral), the louder the note. TI sound is based on the fact that at logical high, the linkport output is 0v; at logical low, the linkport output is 5v. By quickly switching between 0v and 5v, you can make the diaphragms in the headphones vibrate and create sound. Of course, because you only have two voltages to work with, you therefore cannot change the volume of the music (well, you could do a PWM scheme, but it would sound really awkward), only the frequency. Careful cycle counting, or use of interrupts, will allow you to switch the state of the link port at a set speed and produce a desired frequency.
Makes sense? If that all sunk in, I'll next discuss monophonic, stereo (biphonic), and quadraphonic music.