Anyone with experience with CAN bus + Teensy 3.6? Answered
I have been recently messing around with the Teensy 3.6, of which the MK66FX1M0VMD18 it's rocking is probably one of the most powerful microcontroller I have ever messed with. (180MHz ARM Cortex M4, 256K RAM, hardware FPU, far more than enough GPIO, and an insane amount of serial interfaces!)
I am particularly interested in the 2 CAN bus interfaces that it's sporting. However when loading the example code (which explicitly states it is only compatible with the Teensy 3.6! as only it has 2 CAN busses) I have not had much luck getting it to work.
I don't really understand what CAN_TX and CAN_RX are suppose to be. I would assume it is simalar to UART where TX is connected to RX and RX is connected to TX. However at least with the MCP2551's I also ordered, the RX (on this chip) is actually an output while the TX appears to be an input. As it turned out, I was not able to use this chip due to it being a strictly 5V logic component.
So after having discovered that, I decided to just connect the TX of CAN1 directly to RX on CAN0, and vice versa. Using the Object Oriented CAN example, I get absolutely nothing. If I swap the connections, connecting the low-impedance TX to the other low-impedance TX, and RX to RX, I also get nothing, but if I bring my hand close to the wires, or touch and feel around some of the pins, I will get some packets through and to appear on the serial monitor, almost as if one of the pins is acting as an input and of course it's floating because I don't know which pin that would be, as there is no code or comments to indicate such a button. I honestly have no idea what the hell is going on, and don't have access to a proper scope to see what is going on.