Power Pic RGB with voltage controlis a circuit that generates many colors using a RGB LED and those colors can be changed using two independent voltages, supplied by some external device, in order to select the color (Hue) and its intensity (Value)!
The idea originally came from Artur Grycuk who wanted to interface his Theremin Music Controller with RGB Leds. The controller has two output voltages, one for volume and another for pitch, ranging from 0 to 4 and 0 to 5 volts respectively.
Design
Unlike the previous Power Pic RGB with infrared remote control and Power Pic RGB project, this one is designed to be a development version, without any PCB.
Here’s the concept diagram:
The microcontroller in this circuit is similar to the one used in the other Pic RGB projects. The software is compiled only for a PIC 12F675 because this model includes an ADC but may be easily changed to another pic12F*, as long as it has an ADC and a free timer to generate the PWM.
Schematic
The schematic is also very similar to the others, except that it now contains two pins configured as analog inputs.
At the left side is the 5V power supply. The pic 12F675 microcontroller is in the middle and the LED driver at the right. This driver consists of three mosfets that will drive the LED. Click on the image to enlarge it.
As stated on all other Pic Rgb circuits, each mosfet can drive a maximum 600mA through its drain but according to Prolight each LED (red, green and blue) can only sustain 300mA, which makes this mosfet perfect for the job.
For more detail: Power Pic RGB with voltage control using PIC12F675
