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Topic: 6x TLC5940 32 rgb leds (Read 16751 times) previous topic - next topic


Alrighty, I wanted to add a color organ to this beast. I was thinking on using this circuit and instead of the 3904's just connect to the input of the analog inputs.

I figured the code would go something like:

value1 = analogRead(pin);

if (value1 > somearbitrarynumber){
Tlc.set(0, 4095);
if (value1 > someothernumber){
Tlc.set(1, 4095);

Or maybe something like this:

value1 = analogRead(pin);
value2 = analogRead(anotherpin);
power = value1 * multiplier;     //(multiplier most likely will be 4)
power2 = value2 * multiplier;
for (int channel = 0; channel < 16; channel += 1) {
     Tlc.set(channel, power);
for (int channel = 16; channel < 32; channel += 1) {
     Tlc.set(channel, power2);

In that schematic I found i'm not sure what the pin 11 and pin 4 connected to vcc and gnd are going to. I'm assuming I can ignore it. I'm also assuming 12v is VCC.

I'll have videos of the fully strung fiber optic this weekend, I"m so excited to see how this turns out.


the 11 and 4 pin are for IC1

The only thing i'm not too sure on is how to calibrate for the input analog range of 0-5v for the arduino without an oscilloscope. Will the 20k pots be enough? Will this circuit produce  wave forms 0-12v?or ??


As that circuit can output up to 12V you better include some diode protection on the inputs to the arduino to prevent damage.


Isn't that what the 1N4002's would be connected to?


No, those are the envelop follower diodes.
You need a seriese resistor and catcher diodes to each rail.


Here it is wired up with the fiber optic. I can't wait to program morepatterns




As far as calibration without an oscilloscope goes I should be able to play a sine wave respective to the frequency being passed, then slowly turn up the pot and print the analog read out to the serial line. Or could I use a volt meter with respect to ground (or vground?) and read it as the RMS value and adjust it for P-P value?


Or could I use a volt meter

It depends on the quality of the meter, some cheap ones do not respond well to high frequencies.




Hi there! I´m new to the Arduino world and have little experience with the TLC5940.

I´ve looked through the posts trying to find a way to drive more current using the same IC and found what seems the more suitable one here > http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1271193991 <

I would like to drive 16 Cree RGBW LEDs and I need some 350 mA per channel. Would this be OK? Any suggestion?

Thanks in advanced!


Yes 16 of those should work. You will need a good power supply and a lot of decoupling capacitors as well.


Yes that is the same circuit i used and it works nicely. As Mike said make sure you use a good power source such as a computer power supply that has the 5v and 12v readily available.


Thank you guys! Now, about decoupling capacitors what would you recommend?

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