[Bug] Possible ESC calibration issue

[afwilkin]

Describe the bug

Discovered an ESC cal issue with a branch of 1.16.

This ticket here is just to track it. Will flesh out more in a bit

To Reproduce

Flash mainline onto an NXP board that is mounted onto an x500 airframe, reset all params to firmware defaults, fill out all settings in QGC (red tabs), attempt to calibrate the PWM ESCs.

NOTE: this might not just be an NXP issues

Expected behavior

correct calibration of ESCs

Screenshot / Media

ESC calibration failing:
https://www.loom.com/share/882d61a714554ba5bc06d10cdeb6e422

Flight Log

No response

Software Version

No response

Flight controller

NXP

Vehicle type

x500

How are the different components wired up (including port information)

regular x500 pwm escs into board

Additional context

No response

[DronecodeBot]

This issue has been mentioned on Discussion Forum for PX4, Pixhawk, QGroundControl, MAVSDK, MAVLink. There might be relevant details there:

https://discuss.px4.io/t/px4-sync-q-a-april-02-2025/44681/1

[DroneWuKong]

Just ran this and i'm not seeing the issue via mainline, using QGC Daily and Main.

Log for Main: https://review.px4.io/plot_app?log=a2098618-b574-4ae2-b4a0-e9e7ba45b33d

Log for Daily: https://review.px4.io/plot_app?log=77ec7482-0c7e-42cb-8298-6c1a4ad729c0

[afwilkin]

I am seeing this when I am trying to calibrate ESCs. I do not power on the drone at all, and try to calibrate out of the box

I am seeing an issue when trying to calibrate 6c and NXP flight controllers.

Not the EXACT same issue, but an issue

NXP
Holybro 6C

[afwilkin]

ok, that is what is wrong. The esc calibration appears to fail in esc_calibration.cpp somewhere in "check_battery_disconnected" function.

it works when you

1. connect drone over USB
2. power on drone
3. power off drone (without disconnecting usb)
4. start esc calibration as normal. This should now work

[afwilkin]

digging into the specific code now

[afwilkin]

Yeah this is conditional that is failing:

PX4-Autopilot/src/modules/commander/esc_calibration.cpp

Line 66 in e228456

if (!recent_battery_measurement) {

[afwilkin]

I just flashed 1.15.4 and this appears to ALSO be an issue on 1.15.4.

Going to try on holybro 6c

[afwilkin]

Same issue on pixhawk 6c w/ 1.15.4
https://www.loom.com/share/14b5f8963ad8406696c84c86aeee42fa?sid=31214a3d-703d-4669-a15a-8f1eb77f5865

[afwilkin]

Pixhawk 6c power module: PM02 V3.2
NXP power module: PM02D-v1.4

So, I THINK there are 2 issues

1. the driver for these 2 power modules is different. the PM02 V3.2 seems to publish a battery message when no battery is plugged in, while the driver for PM02D-v1.4 does NOT
2. When PM02 V3.2 is plugged in, there is not an added check to make sure that a battery is plugged in before continuing the ESC calibration