The documentation for the Teensy talks about there being 3 CAN controllers on-board.
In the absence of an oscilloscope perhaps you could use one of the other on-board controllers (with driver) to monitor the output.
The documentation for the Teensy talks about there being 3 CAN controllers on-board.
In the absence of an oscilloscope perhaps you could use one of the other on-board controllers (with driver) to monitor the output.