VESC Canbus Communication

• A CAN Bus frame can contain a maximum of 8 bytes of data.
• Each CAN node has a unique ID, the ID determines the priority (ID 0 is most dominant).
• CAN messages from VESC use an extended ID (EID), containing the COMMAND and CONTROLLER_ID.

CANBus Control

These commands can be sent to a VESC node to control the motor and request status.

Command	ID	Data	Data Length	Data Type	Units
CAN_PACKET_SET_DUTY	0	Motor Duty Cycle	32-bit/4-by te	Signed Integer	Thous andth s of perce nt (5000 0 –> 50%)
CAN_PACKET_SET_CURREN T	1	Motor Current	32-bit/4-by te	Signed Integer	mA
CAN_PACKET_SET_CURREN T_BRAKE	2	Motor Brake Current	32-bit/4-by te	Signed Integer	mA
CAN_PACKET_SET_RPM	3	Motor RPM	32-bit/4-by te	Signed Integer	ERPM
CAN_PACKET_SET_POS	4	Motor Position
CAN_PACKET_FILL_RX_B UFFER	5
CAN_PACKET_FILL_RX_B UFFER_LONG	6
CAN_PACKET_PROCESS_RX _BUFFER	7
CAN_PACKET_PROCESS_SH ORT_BUFFER	8
CAN_PACKET_STATUS	9	Request status	N/A
CAN_PACKET_SET_CURREN T_REL	10
CAN_PACKET_SET_CURREN T_BRAKE_REL	11

• Motor position requires an encoder to be present.

CanBus Status

The VESC can be configured to send status updates at a set frequency.

Triforce Network Topology

```

+—————-+ +—————-+ +—————-+ | Weapon Motor 1 | | Weapon Motor 1 | | Weapon Motor 1 | | CAN ID 3 | | CAN ID 4 | | CAN ID 5 | +—–+—-+—–+ +—–+—-+—–+ +—–+—-+—–+

| | | | | +——————-+

| | | | | | Fight Controller |

| | | | | | |

+——-+————+———+—————–+—-+———————+ |

+-+ | | | | | | +-+ |

120R | | | | | | | | | | 120R |

+-+ | | | | | | +-+ |

+————+————+———+——-+————–+—————-+ |

| | | | |

| | | | CAN ID 0 |

+—–+—-+—-+ +—–+—-+—-+ +——————-+ | Drive Motor 1 | | Drive Motor 1 | | CAN ID 1 | | CAN ID 2 | +—————+ +—————+

```