I want to connect my Beaglebone Black, powered from USB port on my laptop, to OBD connector present in my Ford in order to see CAN traffic with
Beaglebone operates on 3.3V, that's why I am using a logic level converter to interface to MCP2551 CAN transceiver operating on 5V.
I am using pins P9_26 and P9_24 from Beaglebone's header P9.
Is the connection presented on the schematic correct?
Can I connect the Signal Ground from my Ford's OBDII connector with GND from Beaglebone (which I think equals GND from USB) safely?
Is connecting grounds of these two separate circuits (car <-> Beaglebone/laptop) necessary?
If the grounds are not connected - can it pose any danger to the car's transceiver/CAN computer or USB port in laptop?