joeman112
Junior Member level 2
Hello,
Got a nice "little" project that I need some help with.
I'm making a 1m square tile that I plan to have 100 white LEDS in 10 x 10.
I then plan on putting 16 of these tiles together (4m x 4m).
I need to individually tell each LED to change brightness through PC based software (so custom patterns can be made on the PC then sent to the wall of tiles).
My idea was to make each tile modular and have a serial bus running in an E shape.
So my data packet would be:
Tile Address [5 bits] | (LED Address [8 bits] | Brightness [5 bits] x 100)
Problem 1: How can I support my custom protocol and 1Mbs?
5 + (13 x 100) = 1305
The minimum update rate of a tile should be 24Hz (although recommendations are welcome)
1305 * 24 = 31320 bits/second
31320 * 16 tiles = 501,120 bits/second = 1Mbs needed.
RS422? - Reading up there is a maximum device limit of 10.
Problem 2: Controlling 100 LEDs.
I was thinking of using a PIC because I am familiar with them. However, there are not 100 IO ports on any pic. Also, I have read that there is a possibility of overloading the chip 100 LEDs at 20ma and apparently PICs can only output 200ma (10 LEDs).
I have also looked at shift registers, but I think this might affect the PWM signal that change the brightness of the LED.
I know there is a lot to take in here, but any help would be gratefully received.
Many thanks,
Joe
Got a nice "little" project that I need some help with.
I'm making a 1m square tile that I plan to have 100 white LEDS in 10 x 10.
I then plan on putting 16 of these tiles together (4m x 4m).
I need to individually tell each LED to change brightness through PC based software (so custom patterns can be made on the PC then sent to the wall of tiles).
My idea was to make each tile modular and have a serial bus running in an E shape.
So my data packet would be:
Tile Address [5 bits] | (LED Address [8 bits] | Brightness [5 bits] x 100)
Problem 1: How can I support my custom protocol and 1Mbs?
5 + (13 x 100) = 1305
The minimum update rate of a tile should be 24Hz (although recommendations are welcome)
1305 * 24 = 31320 bits/second
31320 * 16 tiles = 501,120 bits/second = 1Mbs needed.
RS422? - Reading up there is a maximum device limit of 10.
Problem 2: Controlling 100 LEDs.
I was thinking of using a PIC because I am familiar with them. However, there are not 100 IO ports on any pic. Also, I have read that there is a possibility of overloading the chip 100 LEDs at 20ma and apparently PICs can only output 200ma (10 LEDs).
I have also looked at shift registers, but I think this might affect the PWM signal that change the brightness of the LED.
I know there is a lot to take in here, but any help would be gratefully received.
Many thanks,
Joe