There may be a lot of RGB LED Drivers out there, but this one is a bit different, its versatile, small, cheap, and is simple to control.
A potentiometer with built in switch is used for the controls. A quick press, switches between color cycling and solid color select modes. Pressing in on the dial and holding, toggles an Intensity control, to brighten or dim the LED. Pressing in and holding again, exits Intensity control. Settings are saved when turned on/off.
It supports common anode, common cathode, or single color LEDs. Selectable via jumper wires.
The PCB is set-up for a single 3 watt RGB LED but, it can be easily made to power a 12 volt string of LEDs in series as long as each color channel isn't more than the recommended 2 watts ( though the transistors are rated for 2.5w ) or 500 miliamp per color channel. Correct resistor for R1, R2, R3 would have to be calculated and changed. Goto Step 7 to View.
This driver is great for ambient lights, mood lamps, display lights, case light for a PC, I have even made a lantern version that ran off 4 D batteries
And of course best of all its free, with PCB layout, HEX file, schematics are available.
ZIP containing HEX, PCB layout, Schematics, & datasheet is below
Download the Dial RGB LED Driver v.1 Datasheet
UPDATE 2/15/12: A new refined version has been released. It is recommended that devices are upgraded to this new firmware. Anyone who has purchased a kit, or programmed PIC can contact me for special price on a new version, or download the HEX from the ZIP file and re-program.
Changes v.1 to v.2:
- Faster PWM Rate
- Better Dimming down to 50%
- Color Select now goes Red -> Green -> Blue -> White (added white)
- Refined user controls
- Fixed misc bugs
I have included 2 modified versions of the firmware both use GP5 as a second button, one toggles the light on/off when the button is pressed, the other version holds the light on/off depending on the state of GP5, designed to work with a QT113 touch sensor. See readme for details.
This Instructable will assume that the kit with a 3 watt RGB LED is being assembled.
If you are not using a 3 watt RGB LED, R1, R2, R3 will be different values try led.linear1.org/1led.wiz to find the correct resistor values you should use, or send me a PM, I will help you out. Choosing incorrect resistor values can cause damage.
The author of this Instructable can not be held liable for any damage or personal loss in anyway resulting from the information in this Instructable. use at your own risk.
Common Anode - Common lead goes to V+
Common Cathode - Common lead goes to V- ( gnd )
Clear a work area, preferably with good light.
Layout the parts and ensure that they are all there.
- PCB - Buy a PCB with Free Shipping
- 12F675 programmed with the firmware Or Buy One Programmed
- 8 pin DIP socket
- 3x 500 ohm 1/4 watt resistor
- 1x 10k ohm 1/4 watt resistor
- 3x NPN Transistors, I chose MPSW45ARLRAG
- 2 Pin Locking Header
- 2 Pin Housings
- 10 Crimps ( Purchased kits come with 12, just in case)
- 3 Watt RGB LED
- 10k Potentiometer, with built in momentary Pushbutton
- A regular Pot 1-10k ohm and a momentary Pushbutton can be substituted.
- 2x 4 Pin locking Header
- 2x 4 Pin housing
- Heatsink for LED
- 2 screws
- current limiting resistors for LEDs
- For a 3 watt RGB Star LED
- 1x 5.1 ohm 1 watt, for Green
- 2x 16 ohm 1 watt for Blue and Red
*Note: these need to be small resistors, 8 mm in length. I've only found PR010001 that fit.
though larger ones can fit, its just not pretty.
- 0.1uF disc capacitor
- 7805 if the input voltage and LED voltage is more than 7 volts.
- Wire, about 20" of twisted pair (2 wires)
A power supply of at least 5 volts, at least 700ma ( 1 amp is better ) is also required.
- Soldering Iron
- Wire Stripper
- Needle Nose Pliars
- Hot Glue
- Electrical Tape
- Volt Meter
- Shrink Tube