Buzzer stops working with MatekH743-bdshot firmware

My quad is running on the Matek H743 Slim. If I use the MatekH743 firmware, version 4.3.6, my buzzer (iFlight JHE) works perfect when connected to the H743 “Buz-” pin. I have RC8_Option set to “Lost Copter Sound”.

If I load the MatekH743-bdshot firmware version 4.3.6 everything works perfectly (including getting esc RPM values) except the buzzer no longer works.

I can switch back and forth between the firmware versions and see the pattern repeated, so I assume this is a firmware issue or some hardware constraint when using bdshot I don’t understand. I’ve attached a set of my configuration settings.

If this is a firmware bug, hopefully it will find its was via this post onto a fix list. If not, perhaps there is some simple workaround. I spent a little time trying to configure one of the servo ports to GPIO to toggle the buzzer on, but that didn’t seem to work either (this could be pilot error on my part).

Backup_051423_bdshot.param (21.5 KB)


Using BDSHOT can take away from other non-important features due to the resource requirements of BDSHOT.
Personally I disable the buzzer anyway, since usually you can hear it inflight. They can also cause fluctuations on the 5vdc for the flight controller.

Sean, appreciate the response. Was able to work around the problem by enabling one of the servo outputs to a GPIO to control the buzzer. Regards, Jim