LED Strips

[Ryan7777]

I have a bunch of experience with the WS2801 based strips, which you can run using shiftout pretty easy. You basically shift in your bits on the data line with each pulse of the clock line if i remember correctly something like this for the WS2801 Strips (my favorite):

noLEDs           CON   32         ' Change this number to number of LEDs in your strip

shftMode        CON   1           ' Shift data out highest bit first. Clock idles low

LEDsDAT         VAR PORTE.0   ' Shift out data port, change as needed

LEDsCLK          VAR PORTE.1   ' Shift out clock port, change as needed 

i                    VAR    Byte     ' Loop variable

Main:

FOR i TO noLEDs                   ' We have to either shift allllllllll the data bits out at once to all LEDs in one SHIFTOUT or for one RGB LED at a time in a loop, much easier this way!, lots of ways to do this.

SHIFTOUT LEDsDAT, LEDsCLK, shftMode, [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1] 'Shift out 24 bits to one RGB LED at a time - should be all LEDS ON (can be varibles too)

NEXT i                               ' Loop till all LEDs loaded

i = 0                                 ' Please be kind, rewind.

PAUSE 1000                      ' For human eyes to be able to see that them LEDs are ON

FOR i TO noLEDs                ' Rinse, Repeat - but turn them all off this time
 
SHIFTOUT LEDsDAT, LEDsCLK, shftMode, [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0] 'Shift out 24 bits - should be all LEDS OFF (can be varibles too) 


NEXT i                           ' A little loopy                             

PAUSE 1000                    ' For human eyes to be able to see that them LEDs are OFF (ever wonder if the fridge light is still on when you close the door?)
               
GOTO Main                     ' Do it till the cows come home!

END                              ' My only friend, The end... (fridge door, The Doors, whatever)

The problem is a lot of newer strips use weirder data protocols which are very timing sensitive. You can make them work, but your PIC is probably going to be dedicated to that, with another pic telling it what to do without a lot of work with interrupts and assembly. Thats why I try to stick to WS2801s

ALSO! if you are driving a bunch of LEDs on your strips, like 32/M in my example, you have to have enough current to drive your strips!!! you also may need to buffer the data and clock lines to be able to drive a bunch of LED controller chips too!!!

-Ryan