Posts made by Dracad

Hi Alex, I had and I still had the issue.

But once I built from https://github.com/modalai/px4-firmware/tree/voxl-fpv-dev and changed BAT1_SOURCE to power module (I originally had it set to ESC), when spinning the motors the current appeared correct and power draw updated correctly! Appreciate the help!

One interesting thing, with BAT1_SOURCE set to the ESC, when monitoring the battery_status mavlink message the current consumed and current battery values were invalid (both set to 0), I would've figured that mavlink message would still be valid irrespective of the source as its only coming from place?

Thanks

Thanks for the reply! Good to know it was a known issue.

One thing, the links you sent point to modalai's fork of the px4 firmware, but alot of changes have been implemented in the mainline PX4 repository. I'd been building off the mainline repo, apologies if this has been answered before or is documented somewhere, is there a document that describes modal ai's release process so I can make sure im grabbing the latest iterations of code?

In QGroundControl, the battery drop down shows that current discharged is always 0 and when monitoring the battery_status mavlink message, the battery discharged and current readings are always 0 (this is the case when BAT1_SOURCE param is either ESC or POWER MODULE).

Looking into the code on github (https://github.com/PX4/PX4-Autopilot tag 1.15.0), in src/drivers/actuators/voxl_esc/voxl_esc.cpp on line 568, we get the current from the ESC's onboard current monitor (the M0138 doesnt monitor every ESC but has one single monitor on ID2 ESC. The normal esc_status message will not show the current on any ESC but a power status packet will be sent from the ESC when requested by the voxl_esc driver). This current appears to always be negative. Negating the value on this line along with changing BAT1_SOURCE param to POWER MODULE causes everything to 'work'. This doesn't seem right, any insight would be greatly appreciated!

Thanks!

When using the later releases (v1.15.0) of px4 software with the voxl_esc library found on the official github (https://github.com/PX4/PX4-Autopilot), when the flight core initially boots, if the ESC is not yet ready (either booted after the flight core or hasn't completed booting by the time the flightcore was ready), the flight core will not detect the ESC and will not be able to drive the motors.

This issue presents itself even when the flight core is powered from the ESC.

It appears to be an ordering problem, if the ESC is powered initially, then power is applied to the flight core this all works correctly. In the ideal configuration, the ESC is providing power to the flight core so powerup order cannot be controlled.

With a mavlink shell, with the ESC/flight core in a not detected state, the voxl_esc task is not running. Manually starting the task with 'voxl_esc start' will then start the process at which point the ESC will be detected and become usable. Looking at the source code (this is still valid on the main and v1.15.0 branches at the time of writing), under src/drivers/actuators/voxl_esc in voxl_esc.cpp, in the VoxlEsc::Run() method we can see that the driver attempts to contact the ESC, if it fails up to num retries, it will then close the task. This doesn't appear to be correct behaviour.

I have implemented a fix on a local branch, but I am unsure of the implications as the firmware that is factory loaded onto the flightcore does not have this issue. Any insights/help would be appreciated! Thanks!