[Noisebridge-discuss] Sanity check on LED matrix design.
Daniel at coloraura.com
Sun May 20 16:18:14 UTC 2012
I'm going to try to make a simple LED matrix display powered by an
Arduino, and wanted to validate my approach with the more experienced
My goal is to have something that will allow several "brightness" values
for each LED. In other words, I'd like each LED to be able to be
independently one of: full bright, 3/4 bright, 1/2 bright, 1/4 bright,
The design has 3 of the Arduino outputs connected to a 74HCT138, to
decode the "column", and then 8 other pins connected to each of the
"row" (with appropriate resisters).
The software part of this would run through each column, and enable the
appropriate rows. I'm hoping to put this process on a 4ms timer, so
that I can interleave on/off states depending on the desired brightness,
and still have the entire matrix update at around 50hz
Does this seem like a reasonable approach, or is it likely to cause too
much flicker? Does anyone know if the 74HCT138 can keep up with this
pace? How about the Arduino? The Arduino will be doing more than just
the display part of course, since I'll have to actually create something
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