Starling 2 px4 topic description document?
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Hardware: Model - D0012, Flight controller - M0154
Software version: VOXL 2
What I am trying to do:
I want a document containing a detailed description of the topics/messages recorded by the px4 in the ulog file.
For e.g. What information is contained by the actuator_outputs, actuator_motors datasets.What actually happens: (error messages, behavior)
I have the message description available in the .msg file; but it contains information about what should be the datatype of the message rather than what the data represents or which signal it is logging.Logs / pictures: Below is the description of actuator_outputs dataset, as present in the actuator_outputs.msg file:
uint64 timestamp # time since system start (microseconds)
uint8 NUM_ACTUATOR_OUTPUTS = 16
uint8 NUM_ACTUATOR_OUTPUT_GROUPS = 4 # for sanity checking
uint32 noutputs # valid outputs
float32[16] output # output data, in natural output units -
Hi @kdeshmu2, the PX4 uORB message reference has a page per message with field descriptions and units where PX4 defines them: https://docs.px4.io/v1.18/en/msg_docs/
For the motor topics on Starling 2 (VOXL ESC), we added a table here: https://docs.modalai.com/voxl-px4-files/#logged-topic-contents
In short:
- actuator_motors: motor commands from the control allocator, normalized 0 to 1
- actuator_outputs: the same commands scaled by the voxl_esc driver to RPM, between VOXL_ESC_RPM_MIN and VOXL_ESC_RPM_MAX
- esc_status: ESC feedback per motor (measured RPM, voltage, current, temperature, power)
The voxl_esc driver source is here if you want to see exactly how the outputs are produced: https://github.com/modalai/px4-firmware/tree/voxl-dev/src/drivers/actuators/voxl_esc
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