# Controlling over 1000 rgb leds

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#### hicksynet

##### New Member
Hi i am about to under go a huge project consisting of just over 1000 RGB led's.

My goal is to create a wall of RGB leds, each color individually controlled with PWM (fading), i would like the wall to be divided up into smaller circuits in which a small number of leds will be controlled from, each smaller circuit will talk to each other via serial and all will be controlled by a PC, Arduino or DMX. I will be controlling each circuit from a Ardiuno mega.

TLC5940 - Made a circuit with 3 of these per board to control 16 RGB leds.

This was my first choice being very easy to use. But i did run into some faults, first was it is a sink driver so finding leds to suit was hard being in Australia. i tried using transistors, and they worked fine for a while but one would drop out every so often plus it took so long to solder up 48 transistors per board. The second was each one is daisy chained in a way that if one of the chips die halfway all from that point will stop working.

MAX7313 - Used 3 per board to control 16 rgb leds

i found with this chip i was unable to use high power leds, everytime i tried i blew the chip. one thing i like was the 2 wire serial unlike the TLC5940 which uses 5. i liked how each one was addresable makeing it very easy to code for.

PIC16F628 - I have not yet tried this chip

this was my latest idea, I'm not sure if it will work well in the large form but it will make the coding a lot simpler by having set code on each chip then control it all by the Arduino or PC. The chip can handle super bright leds and has plenty of information out there on them.

If anyone has any ideas to what method i should choose, or if someone has a completely new idea it would be much help.

#### mneary

##### New Member
How much current do your "high power leds" need?
You don't have to solder individual transistors, there are chips for that. (ULN2803, etc.)

#### nickelflippr

##### Member
If you are looking at PIC's then I would go with a chip that at least has a hardware (M)SSP module for I2C slave mode abilities. The 16f628 could be short on outputs when slave communication is included, plus it doesn't have the hardware SSP module. Not sure why you would mix AVR's and PIC's together, are the PIC's that much cheaper?

An alternate led driver would be the NXP models like a PCA9635, could have the same problems as the MAX7313, don't know. Also interested in the current drive required, if they are 1watt, then that would be problematic.

Mike.

#### mneary

##### New Member
There's no good reason to have a transistor reliability problem. Perhaps the circuit is over stressing them. Can you show us what your driver looks like?

#### kchriste

##### New Member
Forum Supporter
but the problem i was having with them is the reliability issue, they just didnt work as well as i was hoping and occasionally they would stop all together.
With the proper transistors, either bipolar or FET, and the proper current limiting resistors, reliability shouldn't be a problem.
Another idea i was having is to use a micro processor of some sort with lets say 48 I/O's
If you multiplex the LEDs with your micros and build a bunch of identical PCBs which you can network together via IC2, or some other protocol, you can simplify the design. In addition this would make it easily expandable if you design it right.

#### birdman0_o

##### Active Member
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