RGB led matrix control
After learning a lot from my initial LED matrix driver I wanted to go
to the next level, RGB! The problem is to PWM so many leds. Texas
instruments has a wide range of chips that make it possible to PWM a
large amount of leds with current control via a serial interface.
The TLC5940 is a popular chip that is demonstrated here. Only one line
for now is connected and only 16 leds at that. I am still working on
the row multiplexing. This needs to be very fast with minimal ghosting,
the previous led matrix system had problems with that. Instead of using
low Vce transistors for switching MOSFET's are going to be used.
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Last update at: 26-09-2010