CAN - what, why, how in 2015

[FrankJ]

CAN is a digital serial data bus. Somewhat like USB but also a lot different. Each device on the bus has a node number between 1 & 63. 1 is generally reserved since a lot of devices come out the box addressed as one. If you car has an OBD-II port on it, it uses canbus.

The advantages of using can is you can control multiple devices from one pair of wires & transmit multiple fields of data to & from each device.

What does that mean for FRC? More complex motor control with the right controller. You can implement the PID control inside the motor controller. With the 2015 system you will have to run CAN for the compressor. (Even if your code does nothing, the module still gets its enable over the bus). You can get power monitoring from the PD over CAN. Admittedly this includes some presumption about the 2015 rules

What are the disadvantages of CAN? 2014 & earlier, there was some programming gotchas that could take the canbus down. Wiring errors on the bus including the sometimes flaky Jaguar connectors would take the bus down. Power brown outs on the Jags could take the bus down.