GameToy hardware project

These pages describe a sort of blog-ish time log on my 'GameToy' hardware project (stalled indefinitely).

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September 19th, 2006 - Laura

Split this log into separate daily pages, so that new readers may have more fun reading it. Maybe.

The PWM channel I'm using in 'Fast PWM' mode runs at (8000000/256)Hz, or 31250Hz. Laura, in her C incarnation, is too slow to process even two simultaneous channels at 31.25kHz, so I split that to 15625Hz, which happens to be (so I'm told) the horizontal refresh rate of the television.

At 15.6kHz I'm able to play four channels without problems. For the GameToy project, I'll probably have to divide that by two again so that the audio doesn't take too much CPU.

As a filter, I used a simple 10uF capacitor, and based on spectrum analyzer output, it works surprisingly well. A more proper (OpAmp based) filtering will probably be needed eventually, especially if I want to use something else than ear plugs as speakers.

Now that I'm back at school, I checked if the OLED displays are still available, and unfortunately they are not. I guess I'll have to live with the LCD for the time being.

Comments are appreciated.