by tnt » Tue Jul 21, 2015 11:05 am
Yes, I meant the RPi camera. In addition to the 6 high speed line they have I2C and a couple of slow IO (enable/powerdown and led control, nothing critical). But all those slow lines could be multiplexed / shared.
For the motors, the direction and microstep selection could also be serialized. You could use a few daisy chained 74HC595 to have a high number of output for those slow signals and just keep the PWM speed control as a direct connection. Same things for any 'slow' sensor (things like bumper detector), you could serialize them, or use an I2C GPIO controller.
The other I2C isn't routed to any pin, all the MIO pins are taken. But it's available inside the FPGA itself through EMIO if you want and from there you can route it to any of the 48 GPIOs.