CAN listen only configuration for safety critical systems
Systems and methods for communication between a vehicle system and a secure communication bus are disclosed. Systems can include a microcontroller and a transceiver configured to send transmit data to the communication bus, receive data from the communication bus, and send data received from the communication bus to the microcontroller. The microcontroller may be prevented from transmitting data to the transceiver by hardware separation between an output of the microcontroller and the transmit data input of the transceiver. The communication bus may be a CAN bus.
1. A system for listen-only communication between a vehicle system and a communication bus, the system comprising:
a listen-only controller area network (CAN) node in communication with the vehicle system and the communication bus, the listen-only CAN node comprising:
a microcontroller; and
a transceiver configured to send data to the communication bus, receive data from the communication bus, and send data received from the communication bus to the microcontroller;
wherein the listen-only CAN node implements a listen-only configuration, such that the vehicle system is prohibited from transmitting information to the communication bus, by including a hardware separation comprising a CAN bus connector plug that does not include a transmit data pin, the hardware separation configured to prevent the microcontroller from transmitting data to the transceiver.
2. The system of claim 1 , wherein the communication bus is a CAN bus.
3. The system of claim 1 , further comprising a differential pair for communication with the communication bus.
4. The system of claim 1 , wherein the system comprises at least one printed circuit board (PCB).
5. The system of claim 4 , wherein the at least one PCB comprises at least one signal trace, and the hardware separation comprises a removable jumper unconnected from a signal trace of the at least one PCB.
6. The system of claim 4 , wherein the at least one PCB comprises at least one pad, and the hardware separation comprises a pad of the at least one PCB unconnected from other circuitry of the at least one PCB.
7. The system of claim 1 , wherein the hardware separation is disposed at or within the microcontroller.
8. The system of claim 1 , wherein the hardware separation is disposed at or within the transceiver.
9. A method for establishing communication between a vehicle system and a communication bus, the method comprising:
providing a microcontroller;
providing a transceiver configured to send transmit data to the communication bus, receive data from the communication bus, and send data received from the communication bus to the microcontroller; and
separating, via hardware, the transmit data input of the transceiver from an output of the microcontroller to prevent the microcontroller from transmitting data to the transceiver, wherein the separating comprises
configuring a printed circuit board (PCB) or electrical connector to prevent the delivery of data from an output of the microcontroller to the transmit data input of the transceiver such that the vehicle system has a listen-only configuration with respect to the communication bus.
10. The method of claim 9 , wherein the communication bus is a controller area network (CAN) bus.
11. The method of claim 9 , wherein the separating via hardware occurs at or within the microcontroller.
12. The method of claim 9 , wherein the separating via hardware occurs at or within the transceiver.
13. The method of claim 9 , wherein the separating via hardware comprises disconnecting and/or removing a pin of an electrical connector from other circuitry.
14. The method of claim 9 , wherein the separating via hardware comprises manufacturing a PCB or electrical connector configured to prevent the delivery of data from an output of the microcontroller to the transmit data input of the transceiver.
15. A vehicle, the vehicle comprising:
a controller area network (CAN) bus; and
a plurality of CAN nodes, each CAN node associated with one of a plurality of vehicle systems and comprising:
a microcontroller; and
a transceiver configured to communicate with the microcontroller;
wherein the plurality of vehicle systems includes:
a secure first vehicle system; and
a second vehicle system having a listen-only configuration, wherein the CAN node associated with the second vehicle system implements the listen-only configuration by including a hardware separation between an output of the microcontroller and a transmit data input of the transceiver, the hardware separation comprising a CAN bus connector plug that does not include a transmit data pin.
16. The vehicle of claim 15 , wherein at least one of the plurality of CAN nodes comprises at least one printed circuit board (PCB).
17. The vehicle of claim 16 , wherein the at least one PCB comprises at least one signal trace, and the hardware separation comprises a removable jumper unconnected from a signal trace of the at least one PCB.
18. The vehicle of claim 16 , wherein the at least one PCB comprises at least one pad, and the hardware separation comprises a pad of the at least one PCB unconnected from other circuitry of the at least one PCB.
19. The vehicle of claim 15 , wherein the hardware separation is disposed at or within the microcontroller.
20. The vehicle of claim 15 , wherein the hardware separation is disposed at or within the transceiver.