It’s that time of year again where the thermometer drops, the sun sets earlier, and we try to warm our hearts with the solstice festival that is common in our own respective cultures. Of course we all need a few strings of lights, but wouldn’t it be great if we had PWM controlled dimmable lights?
When he started out on his PWM-controlled, AC-powered light box, [Waterbury] immediately realized that relays were not going to be an optimal solution. The best way out of the mess he dug himself into would be via zero crossing. After getting a transformer wired up to a transistor for the detection circuit, a short bit of code was written in the wee hours of the morning and a proof of concept was had.
With the control box complete, [Waterbury] hacked up a quick VB app and piped the output of a WinAmp visualizer into the lights via serial. The Inception demo was great, but finer-grain control was needed. After seeing a Hack a Day post on a nice equalizer chip, the seven band output on IC were converted to UART.
[Waterbury] took his seven-band AC-controlled light box to a Halloween party with his synth and the results looked awesome. You can check that out after the break, but we’re really waiting to see his Christmas decorations this year.