A little background: I've got a computer that has to be in my bedroom and on almost 24x7, but it's got incredibly bright LEDs. They're pretty during the day, but it's making it hard to sleep. I've got a working lo-tech solution (note cards and gaff tape), but I'm hoping to use an Arduino to control the brightness of these LEDs. Also, I'm a software developer who has never messed with electronics before. I know programming well, but I am a completely new to hardware electronics.
My motherboard has LED outputs for different functions (power, wifi, hd activity, etc.), and I'm wondering if I can connect these to inputs on an Arduino board that would then drive the outputs for an analog output to the existing or new LEDs. I don't have a multimeter yet so I'm not sure what the output is, but I'd guess it's 3.3 - 5 volts from the motherboard and pretty low current.
Is this a possibility? If so, how would I go about doing this?
Isn't using a $30 Arduino an overkill for just dimming some led? Just add some resistors to the circuits. Or, if you just want to sleep at night, connect them through a switch.
Even if you want some kind of time based controller (auto-switching on and off at morning/night) there are more affordable ways to do that
sn't using a $30 Arduino an overkill for just dimming some led?
Well not if you want total control, like putting an ambient light sensor and using the output from this to control how bright the LEDs are. Using an arduino you can tailor the light detected / LED brightness curve to be exactly what you want.
I would suggest removing the LEDs, running two wires from each LED to the Arduino (signal and ground) and then wiring the LEDs to the Arduino PWM outputs (through a suitable resistor).
However do make sure that the signal from the computer is 0 to 5V with the LED disconnected. It should be but you better make sure. Failing that put a series resistor and catcher (or clamping) diodes just in case.
That is the plan, Grumpy_Mike. Only problem is this is my first foray into electronics, so I've had to buy a fair amount of equipment. I'm having to buy slowly to keep the wife from noticing exactly how much this whole thing will cost, but I should have everything I need by next weekend. I'll let you know how it goes.
