TLC5940 with RC522 RFID Reader

Other Hardware LEDs and Multiplexing
1

Hi, I am trying to get the TLC5940 chips, used to drive 10 RGB LEDs, to work with the RC522 RFID readr/writer.
Since they currently both use MOSI/MISO, they are conflicting with each other. I noticed the TLC5940 does not have a CS pin like the RC522, so I am thinking it would be best to use I2C or the BitBang method (however, I want to enable some simple LED animations, so speed is a consideration).

Both the RFID and TLC5940 work with their respective code. But as soon as I call the Init functions together, nether work.

What would be the best way to get both of these working well together?
What are some architecture solutions for this?

2

Since you are likely to need the speed for TLC5940 I would dedicate the hardware SPI interface to that and use a software SPI interface for the RFID reader. You will, of course have to modify the RFID reader code considerably.

See: http://forum.arduino.cc/index.php/topic,117356.0.html

3

Awesome tip John, just what I was looking for. Thanks!