DroneCAN Telemetry
DroneCAN telemetry is sent using the following messages, each message type has a configurable frequency to be sent at, see:
1034 ESC Status
This is the primary DroneCAN ESC telemetry message, by default it is sent at 10 Hz. The implementation of the error_count field deviates from the DroneCAN specification as described below.
Error Flags
The exact structure is currently undergoing integration and testing and may change in the future. Please refer to changelogs for more information.
To quickly reveal error conditions and warnings, the ESC status message error_count field is used as a custom error/warning flag bitfield instead of counting total errors. This deviates from the DroneCAN specification.
When there are no errors, this field will always read 0. When an error or warning condition is active, the Most Significant Bit (MSB, bit index 31) is set to signal that this is a custom warning. From there, the flags are set to true according to the following conditions.
Bit Position | Error/Warning | Description |
|---|---|---|
0 | Over Temperature | Temperature has exceeded the configured temperature limit |
1 | Bus Over Current | Bus current has exceeded the configured bus current limit |
2 | Phase Over Current | Phase current has exceeded the configured phase current limit |
3 | Over Voltage | Bus voltage has crossed over the over-voltage threshold |
4 | Under Voltage | Bus voltage has crossed under the under-voltage threshold |
5 | Excess Voltage Ripple | Bus voltage ripple is outside tolerances. This can lead to shorter lifetime on the capacitors. This can also signal unit degradation and require investigation. |
6 | Signal Loss | Set if the throttle signal has timed out |
7 | Motor Saturated | Detected a motor saturation and started reducing output drive (foldback) until control is regained |
8 | Motor Over Temperature | Motor temperature has exceeded the configured motor temperature limit |
9 | RPM Limit Reached | Controller has reached the configured maximum rpm limit |
10 | Error Active | Controller has entered error state |
11 | Output Shorted | Bridge detected as shorted during the startup short circuit test |
12 | Startup Check Failed | Bridge and Comparators have failed startup checks |
31 | Custom Status | Set to true to indicate this custom bitfield is in use |
1036 ESC Status Extended
This message contains additional ESC telemetry. By default this is sent at 1 Hz.
Status Flags
The status_flags field is used to communicate more states. By default, this is at a lower frequency to the 1034 Status Message, and is used for less time critical statuses.
Bit Position | Error/Warning | Description |
|---|---|---|
0 | Motor Armed | Controller is in an armed state and can drive the motor |
1 | Motor Running | Controller is actively driving the motor |
2 | Motor Parked | Controller is parked |
3 | Active Free Wheeling Engaged | Active Free Wheeling has been engaged |
4 | Ignoring Calibration | Unit calibration values are being ignored |
5 | Prop Parking | Controller is in the process of parking the motor |
Error Flags
The Circuit Status error_flags field is unused.