So I’ve been wanting to dabble in electronics for a while now but I’ve never had a project that i’d like to sit down and do, until now.
I’d like to try and use a battery powered arduino pro mini to run a 3W RGB LED with dimming for each die on the LED. Now I’ve done a bit of research but i’d like to make sure A) its actually doable and B) my research is correct or at least on the right lines.
I’d first looked at just using the PWM pins to drive the LED, but i then realised that they wont provide any where near enough power to the LED. The LED needs 350mA the pin can only supply 40mA. So I will need an external power supply for the LED.
To use and regulate this i will need a constant current driver, one that supports PWM if i want to be able to dim each die individually. I found a post in the LED forums of someone trying to do this with just a single LED and I’ve tried to extrapolate from there. (http://goo.gl/oA6TTj)
My actual plan.
4 li-ion 3.7v batteries, configured as two pairs in parallel. Should give me a power source of 7.4v (http://goo.gl/7BJ6yz)
3 Dimmable LED Drivers (http://goo.gl/Y5TYss)
1 RGB 3W LED (https://www.sparkfun.com/products/8718)
1 Arduino Pro Mini (http://arduino.cc/en/Main/ArduinoBoardProMini)
I’d run the arduino and the 3 LED drivers in parallel and then hook up the PWM pins 3,6 and 9 to each Drivers PWM pin.
I’ve tried to do a circuit diagram for all of this but i’m very much a beginner so i have had to box out the components but hopefully it will be understandable.
If this is actually doable i hope to extend it with one of these and change the colour on the fly via bluetooth
This project should allow me to replace the innards of a light saber and give me the ability to control the colour of the blade.
So I hope I’ve gotten most of this right, either way i look forward to your replies/help.