CAN Bus Signalling

Settings for configuring CAN bus signalling can be found here:

Terminating the CAN properly ensures signal integrity during operation. It is recommended that each end of the CAN network be terminated, this usually means that termination is enabled on the unit farthest away from the flight computer.

Each motor controller unit supports a software configurable termination which, when enabled, connects an onboard 120 Ohm resistor to the bus.

The units support the DroneCAN protocol over CAN bus. Connection over DroneCAN allows for motor drive, telemetry, configuration and firmware updating. The motor controller can be connected to Hargrave Configurator through DroneCAN for an improved configuration and firmware updating experience and access to on device logs.

The units support Dynamic Node Allocation (DNA) within the DroneCAN ecosystem, allowing quick connection to an existing network. The downside is that on any given power-up event, the unit may change the Node ID it is assigned while on the network. This makes it difficult to review data and may even result in units not connecting if DNA is not operating. If all devices are known on the network then it is recommended to force the node IDs to a known value, when enabled the preferred Node ID is forced. This ensures a given unit will connect using only the given ID. However, duplication of IDs should be avoided. Forcing a Node ID can reduce the time taken for the unit to be on the DroneCAN network from start-up.

The ESC Index determines which throttle command a motor controller will respond to, each motor controller must have a unique ESC index to be driven separately over DroneCAN.

DroneCAN supports an additional mechanism through the 1100 ArmingStatus Message . By default this message is required to drive using DroneCAN signalling. The unit must receive a DroneCAN arming packet with the ‘STATUS_FULLY_ARMED’ status within the configured armed message timeout (1s default duration) to remain armed or driving.