Topic: How to get SPI from Chumby One?
We just saw a demo of the Chumby One at the Homebrew Robotics club last night, and it looks like it has a lot of potential as a robot brain. So please pardon the newbie question -- I've been studying schematics and googling and so forth for several hours, but that is the extent of my Chumby experience.
I'd like to lash up a CAN bus controller via SPI. From searches I've done, it sounds like SPI is somehow brought out on the Chumby One chumbilical connector. I'd like to buy a clue here :) The schematics talk about I2C at the chumbilical, but not SPI, so I'm guessing the SPI pins are multiplexed at the CPU with something else. Is there some document that I am not finding that explains the chumbilical connectivity and design rules a little bit more?
For my project, if I can get MISO/MOSI/SCK, a chip select, 5V, and gnd I should have a solution to putting a Chumby One on my CAN bus. Chumbilical seems like the way to do that, but if there is a better way, a clue would be appreciated.
Any hints appreciated,
(BTW -- from googling it looks like some people are using a USB<->CAN adapter to get a Chumby onto CAN bus. Unfortuantely, USB has significant latency, so closing a control loop over USB is problematic except at very low loop frequencies -- not suitable for many robotics applications.)