RGB mood light


I've created a lot of simple RGB controllers before there were satisfying, commercial solutions available.

This one was my last attempt from 2007 to make a universal, simple controller without unnecessary features.

The device is somehow obsolete now since I switched to the milight system. 





Example Setup

More Details


Instead of just fading through R->G->B, I am using a static set of colors, for both autofading and manual select.



No need for thick cables, just one cheap standard USB AB cable from the control unit to the driver.



Switching between colors looks crappy. I implemented a fader with variable fading length, fast for manual switching, slow for the auto fader. It does not block any interaction, it just adapts the current output setting to a given setting the whole time.



The ambient air temperature is converted to 18 color levels from blue (~17°C) over green to red (~25°C)



The subjective perception of brightness is (nearly) logarithmical, you must pay attention to this if you want a linear scale.


Control Unit

Schematics still need to be drawn :)
source code
Note: this is an old beta with linear scale, the most recent version will follow soon.
The lcd lib works for hd44780 lcds.

Remote Control

The remote control is a cheap 4 channel module. It has 5 outputs: channel 1-4 (T/D-latch type) and one called "VT" which is high as long as a button is pressed. Because the outputs are t-latches, you have to XOR current and last state whenever VT goes high in order to get the pressed button.

Temperature Sensor

The sensor is a KTY81-120, wired this way:
Of course, not very accurate, but enough for this purpose.


The driver couldnt be any easier: 3x BD131 (NPN), 3x 470R (base) and plugs for the LED modules (molex), power supply (dc plug) and controller (usb).