Sunday, November 2, 2008

Fun with 555's (part 1)

Direct resistor voltage limiting is IMO a rather crude way of controlling LED brightness/power, as the resister has to handle the entire current of the LED (or more if you make the mistake of trying to do it parallel) When I was playing around with FPGA's a while ago I was able to use the FPGA as a PWM to nicely control LED brightness.

My analog parts kit has a 555 analog->digital timer IC in it, and I had heard you can make a PWM with it*, so that seems like a good second step in my journey.

(* - A cheap 8-pin microcontroller would also work. And be more fun.)

A good writeup is here:

I took this and tried to transcribe it into an Eagle schematic (lest this entry become completely unoriginal) I also made a board, although I'll never actually produce it so don't take it seriously. A microcontroller-board would be far better. ;)

For more information on schematic/board layouts, go here: - the board layout stuff's the next tutorial.

Today was too busy so I don't actually have time to wire it up on the board. Or post pics of the very simple setup...

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