Arduino + TLC5940

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi there :0)
I got my TLC5940 Chip today and wanted to play arround with it.. yet unfortunately i seem ti be unable to use it...
I was not using the code i found at the playground as it was not what i was looking for (in terms of simplicity of use) but i found the follwiing library: Arduino/Libraries – Metalab Wiki
Can someone tell me how to wire everything up? I was doing the SIN etc pins just like the cpp file told me, but i have had no luck yet in running even a single led through it - guess that happened because i didnt set the cables for Power etc right... i was connecting GND to GND and Vcc to 5V - and i think the clue lies somewhere there..

2

OK, this seems to be solved.. i found Acelone's library with a good extended howto on how to connect the whole thing :0)

3

Alright so far i got one of them running, but when i try to chain them i run into a few problems.

 * -  Put the longer leg (anode) of the LEDs in the +5V and the shorter leg (cathode) in OUT(0-15).
 * -  +5V from Arduino -> TLC pin 21 and 19     (VCC and DCPRG) 
 * -  GND from Arduino -> TLC pin 22 and 27     (GND and VPRG)
 * -  digital 3        -> TLC pin 18            (GSCLK)
 * -  digital 9        -> TLC pin 24            (XLAT)
 * -  digital 10       -> TLC pin 23            (BLANK)
 * -  digital 11       -> TLC pin 26            (SIN)
 * -  digital 13       -> TLC pin 25            (SCLK)
 * -  The 2K resistor between TLC pin 20 and GND will let ~20mA through each LED.
 * 
 * If you are daisy-chaining more than one TLC, connect the SOUT of the first TLC to
 * the SIN of the next.  All the other pins should just be connected together:
 *   BLANK of TLC1 -> BLANK of TLC2 -> ...
 * The one exception is that each TLC needs it's own resistor between pin 20 and GND.
 *
 * Alex Leone <acleone ~AT~ gmail.com>, 2008-11-26

I now have connected every pin coming from the arduino into the corresponding pin of the first TCL as well as into the corresponding pin in the second TCL - without, of course - SIN which is connected to SOUT on the first TCL. Now the thing is like that. I have a simple light which should run through all LEDs on the board, It works for the first TCL but it doesnt run through the second array. Even worse: The LEDs on the second TCL seem to blink in an erratic and random way.. alouth Out15 corresponds to TCL1 Out 11 or 12...

Any ideas on what i do wrong?