POAlamp = Arduino + TLC5940 + 3W RGB Leds

June 12, 2009

A lamp should be bright and nice-looking.
For me a lamp should be bright, nice-looking, interactive and a touch of a miracle.

That’s the lamp:
The lamp

That’s the “quick and dirty” housing:

And that’s the interface:

Mr. Bear, stuffed with electronics…

And some needed electronics:
Shield for the Arduino

Lamp runs in autoMode:


//Ā  a short update for those who want to build something like that…


Actually the electronics are still on the protoboard and do their work.

I would recommend a better solution for driving the leds. There’s a nice explanation on the ‘mikrocontroller.net’ platform, I’ve just put it through the googleTranslater. They use a cheap and widely available switching regulator to get the right current through the led. In Germany the MC34063 is available for 0,27ā‚¬ at Reichelt.de .


Part List for a 5x3W LED lamp:

More information about the TLC5940:

Arduino library: http://code.google.com/p/tlc5940arduino/

Documentation for a fading: http://students.washington.edu/acleone/codes/tlc5940arduino/html_r014/structTlc__Fade.html

My code is really messy, but I would share it… it works nice.



  1. very nice! especially the Mr. Bear interface šŸ˜‰ The ‘needed electronics’ show more than 20(!!) IC what are they for? Isn’t one TLC enough?

  2. Hi Tobi, the TLC is great and could run leds with 120mA constantCurrent,
    but my commonAnode 3W RGB LEDs need 350mA through each channel.
    I used ULN2003 TransistorArrays (they are just about 70cent for 7channels) and 1W resistors to get enough current through.
    The ULN2003 needs inverted signals on the base, so I used 74HC04 HexInverter to get the right HIGH and LOW signal.

    The “ArduinoShield” uses 3x TLC5940, 8x 7404 and 8x ULN2003 for 48 channels of PWM, so I can drive up to 16 HighPower RGB Leds šŸ™‚

    I’ll put a schematic together and update the post for more details…


  3. this is grate. looking forward to seeing the schematic, dose the circuit board and led’s create much heat?

  4. Hi:

    I like your proyect, did you say/could/want post some more info?, schematics, diagrams, maybe sold a PCB or something similar? I really want to replicate your project but maybe with some 1w(each color)RGB leds, have the tlcs, ordering the unl2803s(could use this instead of 2003?) and need to order the 7404 and the 74HC04 but looking for more info, schematics or some guidance.

    Excelent! Job!


  5. project… not proyect.

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