Controlling alot of LEDs from Arduino or AVR. Maybe 74HC595...

[Sid 03]

I am trying to create a project much like like a Marquee sign, I want to be able to control hundreds of LEDs from a set of chips.

From my research I found the 74HC595 chip and using a bunch of these would probably work, but it would be nice if I had the ability to change each intensity of each LED like each LED pin had its own PWM controller on each LED ?

Is there a chip-set out there that would do some thing like that ?

Thanks
Sid.

 

[DJ Delorie]

\"hundreds\" means an array of 10x10 to 30x30 or so. This is not outside
the realm of possibilities for a small MCU with enough pins. Even using
a second MCU just to run the leds wouldn\'t be *too* tricky. Next up
would be using an FPGA to run the matrix, since you have far more pins
and hardware PWM options. At the top of the list would be an LED
display controller perhaps? Or an OLED display driver?

TI has a range of LED display drivers, like the LP5890, if you can
solder them. And obtain them ;-)

Or you could build your display out of smart RGB leds, like the kind
they use on programmable led strips, and let them manage their own
brightness.

 

[Sid 03]

On Friday, May 6, 2022 at 4:51:25 PM UTC-5, DJ Delorie wrote:

\"hundreds\" means an array of 10x10 to 30x30 or so. This is not outside
the realm of possibilities for a small MCU with enough pins. Even using
a second MCU just to run the leds wouldn\'t be *too* tricky. Next up
would be using an FPGA to run the matrix, since you have far more pins
and hardware PWM options. At the top of the list would be an LED
display controller perhaps? Or an OLED display driver?

TI has a range of LED display drivers, like the LP5890, if you can
solder them. And obtain them ;-)

Or you could build your display out of smart RGB leds, like the kind
they use on programmable led strips, and let them manage their own
brightness.

DJ,
The \'LP5890\' chip has some nice features, it would work. Thank you for that.
What did you mean in your last statement ? \"... let them manage their own
brightness.\" How would they do that ? Is the PWM feature built into the LED ?
Sounds expensive.

Thanks

 

[DJ Delorie]

Sid 03 <sidwelle@gmail.com> writes:

The \'LP5890\' chip has some nice features, it would work. Thank you for that.
What did you mean in your last statement ? \"... let them manage their own
brightness.\" How would they do that ? Is the PWM feature built into the LED ?

Yes. The LED itself has a tiny MCU in it with a serial port.
For example: https://www.adafruit.com/product/4684

> Sounds expensive.

Very

 

[Phil Hobbs]

DJ Delorie wrote:

\"hundreds\" means an array of 10x10 to 30x30 or so. This is not outside
the realm of possibilities for a small MCU with enough pins. Even using
a second MCU just to run the leds wouldn\'t be *too* tricky. Next up
would be using an FPGA to run the matrix, since you have far more pins
and hardware PWM options. At the top of the list would be an LED
display controller perhaps? Or an OLED display driver?

TI has a range of LED display drivers, like the LP5890, if you can
solder them. And obtain them ;-)

Or you could build your display out of smart RGB leds, like the kind
they use on programmable led strips, and let them manage their own
brightness.

Mike Harrison has a video from some years ago that explains a neat hack
for doing that sort of job.

<https://www.youtube.com/watch?v=XlKilhcP_ic>

Cheers

Phil Hobbs