Arduino LED Light Show

[davnirvana]

Hi,

I'm David, a first time user of the Arduino, and a beginner to the field of electronics. I bought the Arduino Experimental Pack and have done some of the basic experiments to get a good understanding of the system.

My project is an LED light show to be synced with a live performance in Ableton Live.

Some initial questions are:

1a. What is the maximum amount of LED's that can be connected to an Arduino UNO? [I've been getting varied answers all over the internet]

1b. I've heard of ways of extending this number - multiplexing/chips. What would you recommend to get the most efficiency?

2. How would one connect audio from a computer into the Arduino?

3. What kind of code is available to have the LED's react to frequency, volume?

4. Although I have found many projects that are similar, can you think of any outstanding projects that I should take a look at?

Thank you so much! I can't wait to get started.

[adafruit_support_bill]

1 - Lots! Using our PWM/Servo driver you can chain them together to control nearly 1000 (992) discrete LEDs. Using digital RGB pixels or strands, you can do more than a hundred with an UNO (memory is the limitation there), or even more with a Mega. If you search the blog, you will find may examples of Arduino-controlled light-shows.

2 - No quick answers for that one. It really depends on what you want to do with the audio.

3 - We don't have any tutorials on that specific subject. But there are quite a few out there on the web. Search for "Arduino color organ" or "Arduino spectrum analyzer" and you will find some good ones.

4 - Here are some that have been featured in our blog: http://www.adafruit.com/blog/category/ledslcds/

[davnirvana]

Thank you so much for your quick reply (and sorry for my late response).

I'm still working. Thank you for your tips!

[tldr]

2 - No quick answers for that one. It really depends on what you want to do with the audio.

since the computing power of your computer is pretty near infinite compared to that of the arduino, it might be best to analyze the audio on the computer and pass data over usb to the arduino telling what to do with the lights.

1a. What is the maximum amount of LED's that can be connected to an Arduino UNO? [I've been getting varied answers all over the internet]

what sort of control do you need over the leds. just on/off, variable brightness, rgb? and how many might you conceivably want? you've got 20 i/o pins on the arduino. let's say you want the uart and one analog pi left available. i've managed to get 8 bit pwm on 18 arduino pins to get 24 bit control of 6 rgb leds. you could multiplex a 9x8 array and get on/off control of 72 leds. you could charlieplex a 17x16 array of, (er, excuse me a moment), 272 leds. problem is the multiplexed solution gives you a 12.5% duty cycle and the charlieplexed one gives you 6.25%. you might want things a little brighter than that.

you can introduce shift registers to multiplex larger numbers of leds at higher duty cycles.

you can use specialized led drivers like the one used on the pwm/servo driver mentioned above.

reading further down this list there is a correlation to higher costs, which brings us to...

the digital rgb pixels or strands. these are really cool and easy to use, but the cost is close to $1/led. i love my lpd8806 strand, but i don't see getting it a brother or sister any time soon.

3. What kind of code is available to have the LED's react to frequency, volume?

still think you ought to do the grunt work on the host and let the arduino stick to driving leds.

[davnirvana]

Hey!

This is great information.

I have decided on using the computer for the analysis. Thanks for that tip. It makes sense.

Still thinking of the other stuff, but again, thanks!