Anyone working on turning peggy into a clock?

I understand each led is not addressable with the kit. Any direction on how to go about changing that?

Thanks!
Ben

The Peggy kit was not really designed for animation, and in the default way to build the kit, control of the LEDs is only by the row-- it's easy, for example, to blink the top or bottom half of a sign while leaving the other half alone, or to build an OPEN/SHUT sign that has only one half or the other lit up at a time. While I'm sure that it's possible to animate the entire 625 LED display with some simple added driver circuitry to give high brightness and in-system programmability, I haven't yet worked out how to do it, primarily through lack of trying. ( I'll get around to it eventually....) The Peggy *can* be built as a charlieplexed display, trading its very high brightness for the possibility of doing simple animations. (Download instructions for that build here; you will need to add 25 extra 27-ohm resistors and either some wire or wire jumpers.) There are some caveats, however. The method given there does not actually work if all of the LED positions are populated-- the voltage drop on the pins used to program the chip is too high. It might be sufficient of a fix to pull the chip out to a separate board (not actually program it in system). Secondly as a work-around, you could just avoid the particular LED locations that are causing the problem, so it's certainly possible to build a clock, which might be a fun thing to try some time.

Still interested in going the charlieplexing route-- it seems like the issue is brightness with lots of LED's, so I wonder-- how is the brightness compared with non-charlieplexed if, say, instead of 90 LED's on all the time, it was charlieplexed with a cycle of three 30-LED images?

Also wonder about a source for 625 2-pin female jumper leads...

-salsa
san francisco

Well, it seems about 1/3 as bright to the eye, of course. Doesn't look nearly so good, unfortunately. It *could* look very good if you only light up a few LEDs at a time instead and manage the locations that are lit quite efficiently.

Many of the major electronics places have appropriate sockets-- I haven't picked any up yet, but I'll try to do so.