Hi thanks,
About SPI :
There is a library for arduino "tlc5940" and "This library uses the PWM output ability of digital pins 3, 9, 10, and 11."
So maybe you're right , no possibility to send 4 PWM on Xbee?
Someone talk about wire and I2C to drive tlc5940, and it is possible to use it with Xbee, right?
Ciao