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Topic: [Mini Arduino Pro] Driving 12 RGB LEDS Questions (Read 2 times) previous topic - next topic

cjdelphi

wow... do you have a link? i have over 100 common anode's ... Even though i asked for common cathode and bought common cathode! 3 lots different supplies they ALL keep sending common bloody anode!







Grumpy_Mike

Quote
So you are suggesting me to use each (3) PWM output for one color and put a transistor on each color line to guarantee the needed current, right?
With this solution i will not have any problem, but all sides will have the same color. Right?

Yes all the sides will be the same colour but with only three PWM outputs you don't have a choice unless you use some other chip to generate the PWM signal for you.

Other options are to go for LED drivers, I like the PCA9685 chip, that is I2C controlled and gives 16 PWM outputs so you need just the one chip to do what you want with a different colour on each side. It will drive up to 25mA per output.

Univers3


Yes all the sides will be the same colour but with only three PWM outputs you don't have a choice unless you use some other chip to generate the PWM signal for you.

Other options are to go for LED drivers, I like the PCA9685 chip, that is I2C controlled and gives 16 PWM outputs so you need just the one chip to do what you want with a different colour on each side. It will drive up to 25mA per output.


Woah, seem perfect this little chip.

Fast questions:
With this chip i need a resistor on each LED too?
if i will use 3 outputs of this chip to drive each R-G-B line of 2-3 RGB leds in parallel, in this case i will need a Transistor, right?

Thank you very much for your precious suggestions.


xl97

#9
Jan 14, 2013, 07:25 pm Last Edit: Jan 15, 2013, 02:40 am by xl97 Reason: 1

@OP-

I think if you use this chip: PCA9685 chip..  you would not need to use the transistor(s) anymore...no?  As the driver chip woudl supply each 'output pin' with 25mA for that 'led'...

going this route (as mentioned) gives you the flexibility to make each wall a color of your choice.. where are transistors is limiting you to the same color for ALL walls..



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