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Arduino controlling 10 RGB groups Answered

Hi everyone!

I recently came across the arduino board and I've been playing around with using Python to control the board. I would like to use my new toy to create an Ambilight like setup for my computer monitor.

The python script I have created for this does quite a good job and runs at about 15-10 fps!

I want to use 10 RGB groups of 3 leds each (3 top/bottom, 2 sides). Since the Arduino only has 6 PWM ports and that leaves me with 5 Digital out ports, I have to multiplex the system.

Since I want to use all colors and not just the 7 combinations normal rgb controlled by on off gives me I designed a circuit that would make this possible.
The refresh times on the PWM ports have me worries.. (changing to a new voltage)
The PWM resistor-capacitor circuit is an option to fix this (I think), it would replace the resistor after the PWM in the diagram.

My knowledge on the subject is a little rusty so I was wondering if someone here would like to look at my circuit design and comment on it.

I'm using MOSFETS, NPN transistors, resistors and capacitors. My LED strips use 12 Volts (hence the mosfets). In a single setup the mosfets work like a charm! 12V goes to the anode of the led group and the mosfet drain goes to the cathode, which is labeled as LED in my diagram.

Tnx Guys/(Girls?)!


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10 years ago

you may want to get a RGB LED Shield as they have a library for controlling several RGB leds and you can replace the leds with mofsets so you can run the strips from it
or you could use SPI and a decoder board http://code.google.com/p/fastspi/