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### Topic: 6x TLC5940 32 rgb leds (Read 14724 times)previous topic - next topic

#### Krolo

#45
##### May 18, 2012, 09:26 am
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);
}
...etc

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.

#### Krolo

#46
##### May 18, 2012, 10:03 am
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 ??

#### Grumpy_Mike

#47
##### May 18, 2012, 10:22 am
As that circuit can output up to 12V you better include some diode protection on the inputs to the arduino to prevent damage.

#### Krolo

#48
##### May 18, 2012, 11:09 am
Isn't that what the 1N4002's would be connected to?

#### Grumpy_Mike

#49
##### May 19, 2012, 12:35 am
No, those are the envelop follower diodes.
You need a seriese resistor and catcher diodes to each rail.

#### Krolo

#50
##### May 20, 2012, 02:26 pm
Here it is wired up with the fiber optic. I can't wait to program morepatterns

https://www.youtube.com/watch?v=WaFdIu16Cco&feature=youtube_gdata_player

#### Grumpy_Mike

#51
##### May 20, 2012, 09:00 pm
Well done looks cool.

#### Krolo

#52
##### May 22, 2012, 07:32 am
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?

#### Grumpy_Mike

#53
##### May 22, 2012, 11:08 am
Quote
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.

#### marklar

#54
##### May 22, 2012, 05:20 pm
That looks fantastic.

#55
Yep, looks great

#### Luciano_Carcagno

#56
##### Jun 01, 2012, 08:39 am
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!

#### Grumpy_Mike

#57
##### Jun 01, 2012, 09:05 am
Yes 16 of those should work. You will need a good power supply and a lot of decoupling capacitors as well.

#### Krolo

#58
##### Jun 01, 2012, 10:41 am
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.

#### Luciano_Carcagno

#59
##### Jun 02, 2012, 02:40 am
Thank you guys! Now, about decoupling capacitors what would you recommend?

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