Using Fallback Signalling
The motor controller supports throttle inputs from multiple simultaneous signals in a priority system. This allows the use of multiple signals for fallback purposes, so that control can continue if the primary signal source is lost. Details on the input priority system can be found here:
Configuring for Fallback
By default the motor controller is configured with CAN bus as the primary signal source and serial as the secondary source, however the settings are optimised for using one signal source or the other. For fallback signalling there are the following configuration considerations:
Set the signal priority for each signal type
Ensure that the signal priorities for CAN bus and serial are set correctly for the system. At least one of the signal sources must have the primary priority, for fallback signalling the other signal type must have the secondary priority. The priority signal will take precedence over the secondary signal when available.
Review configuration for each signal source
Ensure that each enabled signal is configured correctly, this includes selected the appropriate serial signal type, baud rates, arming messages (DroneCAN only) and any other signal specific settings.
Only fallback to armed signals
It is recommended for fallback scenarios and if requiring the DroneCAN arming message to be received, that the βRequire Signal Armed to Fallbackβ setting is enabled. This will require a signal source to be deemed βarmedβ before it will be used by the firmware. There can be scenarios where after losing a DroneCAN signal and regaining the signal that an armed message is received after the throttle command, which would cause the unit to switch to the DroneCAN signal but in a disarmed state leading to drive stopping. Signals that do not support an arming mechanism, such as DShot or PWM, are considered to be always armed.
Require all signals to arm
To ensure that the system is functioning as expected before motor drive can begin, the option to require that all signals are present and armed before the unit arms can be enabled.
Signalling to the unit
For fallback signalling it is recommended to send the same throttle value on all configured signal sources. Sending the same throttle value will ensure a smooth transition between signals, and if using, more reliable PWM re-acquisition.