to control 100 RGB LED

[Mads Husted]

Hi there.

I am trying to find out how to control 100 RGB LED with one uP maybe one ATMEGA8

I have try to take a look on the 74HC595D and TLC5940, and TLC5947, and if I use TLC5947 the I have to use 5 of them.
If so its is possible to control 13 x of the TLC5947 with one uP then I can control 100 RGB LED.

Do any one here know that I can use 13 x of TLC5940 with one uP? of do any have another idea to do it?

Thanks
Mads

 

[peufeu]

TLC5940 datasheet says :
"More than two TLC5940s can be connected in series by connecting an SOUT pin from one device to the SIN pin of the next device."

So you could do just that, your uC has a SPI interface, no problem.

But why not multiplex the LEDs ? That would save on hardware. That depends on the LED current, though. If you want all LEDs to be able to receive full current at the same time, you won't be able to multiplex.

 

[Mads Husted]

okay thanks then I think I will use the TLC5947, because its easy for me to see how to make it.
thanks for youre answer.

mads

 

[Ubergeek63]

what are you trying to do? off hand i would say that the chip will not be able to give you a range of colors even at only 100 RGB LEDs.

if you are looking to drive pictures to LEDs use a chip with an LCD controller on board. It is easy to put logic in to run LEDs as a passive color panel. The LPC2478 is one... not the least expensive solution, but the idea is that if the hardware does the display the software is free to create the images. (the LPC2478 actually has a isolated bus with an SDRAM controller so the cpu can go about it's business)