Another example. This one shows how to use callbacks and C++ classes at the same
time.
Removed any reference to transceivers in the code.

Previously it was hard coded for an SN65HVD234 but on designs without this transceiver it would still try to set the relevant pins. Handle the enable pin yourself now if needed.
Revert "Removed any reference to transceivers in the code."

This reverts commit 822ae1302866ace6a359be0defaafa504c8d30d0.
Removed hard coded SN65HVD support but added back support for setting an enable pin for both canbus ports. Also, added an easier to use and more Arduino-like interface that can be optionally be used. Lastly, you can refer to the canbus devices as Can0 and Can1 now which matches the hardware better.
Added ability to disable the switching of an "enable" pin for each canbus port. Also fixed begin methods to return the result of init so that sketches can determine whether the canbus adapter was set up properly or not.
Update keywords.txt
Update three of the examples to use the new methods and object names.
Make the "allow all" watchFor method more correct. Added another example.
Update howtouse.txt
Merge branch 'master' of https://github.com/collin80/due_can
Merge branch 'master' of https://github.com/collin80/due_can