Serial (DShot/PWM) Signalling
The motor controller supports standard signalling protocols seen on UAV systems. The unit has the ability to automatically detect the serial protocol on the relevant lines, or can be configured to use a specific serial protocol.
DShot
DShot is a digital control signal comprised of a frame containing the throttle signal, telemetry request and a checksum for data validity. It is recommended for applications not requiring CAN Bus. More information can be found here. If the telemetry bit is set and the unit is configured in the correct telemetry mode the unit will respond with a telemetry packet, for more information on telemetry see:
PWM
The PWM control signal is a servo pulse that transmits the throttle command over an analogue signal. It is very simple and is therefore supported on a wide variety of hardware. However, it is susceptible to noise due to a lack of error-checking features and has no native telemetry function.
Pulse widths between 1000 us and 2000 us are accepted, in normal drive mode 1000 us corresponds to a throttle value of 0% and 2000us of 100%. In reversible drive mode the midpoint of 1500 us corresponds to 0% with a configurable dead-zone, a pulse width of 2000 represents 100% and of 1000 represents -100%.
There is an optional moving window filter for PWM values to make the signal more resilient to noise.
Acquiring PWM Signal
To prevent noise on the signal line causing inadvertent motor activation there are additional requirements for acquiring a PWM signal. There must be a series of zero throttle pulses received for the signal to acquire. This behaves differently when using input priority signalling, consult the input priority system docs for more information:
Reaquisition
Details about signal timeout and zero throttle requirements for reaquisition can be found below:
Flight Controller Passthrough
This feature is only available in the 3.1.0 fc_passthrough beta versions.
The ESC supports configuration using the Hargrave Configurator over the serial signal lines through flight controller passthrough (FC passthrough). A compatible flight controller and version of the Hargrave Configurator are required. More details can be found below: