OmnibusF4 bootloader not responding


Hello All,

I am new to the Dronecode community, and I am very impressed by what has been done so far: Excellent Work!
I have bought a Omnibus F4 V3 and flashed the bootloader as detailed in the associated guideline.
I have then built the firmware and tried to upload it without any success so far…
I got an error message “Loaded firmware for board id:42,0 size: 994829 bytes (96.38%), waiting for the bootloader…” then I got “write timeout” errors
I have tried to use QGroundControl to upload the firmware but I also get a “board is not responding error”.
I use Ubuntu 16.04 on a Virtual Machine but I also get the same error when I use QGroundControl on Mac OsX.

I have searched for Omnibus F4 issues but I could not find a similar issue.

Thank you in advance for your help.


I have both Bootloader and Firmware repos on my machine and after building the bootloader I go to the Firmware directory. Thhen, after verifying I see the device show up when plugged into USB, I use these:
Unplug, push/hold reset button on omnibusF4 and plug into USB

dfu-util -a 0 --dfuse-address 0x08000000 -D …/Bootloader/build/omnibusf4sd_bl/omnibusf4sd_bl.bin
make -j1 omnibus_f4sd upload


Hi @CorentinD

Do you have another board, such as a Pixhawk that you could compare against? Maybe there’s a problem with the USB cable or the VM?
In general, there are different Omnibus board variations, and PX4 has only been tested on a few of them (the ones on the documentation). So it’s possible that there is indeed a problem with your board.
Another important thing to know is that we recently had a breaking change for the Omnibus board, so make sure to use latest master for both the Bootloader and the Firmware. The changes are here:


Hi @dlarue and @bkueng,

Thank you for your answer.
I think that the problem is coming from the Virtual Machine thing…
I will install the Px4 dev env. on Mac OSX and give it a try.
Will post about it when I will find time to give it a try :slight_smile:



Hi @CorentinD

I am experiencing a very similar issue to you with an Airbot Omnibus F4 Pro V3 SD.

Have you had any success finding a solution?

QGroundControl crashes or sends the following error when attempting to flash the flight controller:

Found device: PX4 FMU V2
Error: Sync: Send Command: Get Command Response: Timeout waiting for bytes to be available
Upgrade cancelled