Zubax GNSS firmware v2.0

Firmware version 2.0 has been released!

If you’re using PX4 v1.0 (it should be released today or in the following days), please follow this guide to update your Zubax GNSS: zubax.com/news/zubax-gnss-firmware-update-v20

Ran into a problem? Let us know in this thread.


Hi Pavel,
If I understood well this firmware update must be done just for PX4 firmware users and NOT for APM users…

So far, yes. APM will update its UAVCAN stack at some point (hopefully soon), which will then require APM users to upgrade their Zubax GNSS too.


I attempted a firmware flash on my GNSS V2 board but get the following msg:

Process failed, please try again.
Error: STM32LoaderException Invalid response while waiting for ACK:0xff

We have been having problems with our board since receiving it and are going through a number of steps to resolve the problem. Flashing the firmware is an attempt to fix the board. Thoughts?

Hi Derek,

This utility is only applicable for Zubax GNSS v1. The firmware of the version 2 can be updated via UAVCAN, however you don’t need to do so since to date no major updates were released. As far as we know, the stock firmware operates well and requires no fixes.

What kind of problems you’re experiencing with the device?

Regardless of how we configured the Pixhawk, we could not get the GNSS V2 to send a GPS stream. We had no problems getting the original GNSS to communicate with the same Pixhawk, so we know the latter is fine.

NMEA stream over Putty showed all zeros for the coordinates.

Direct connect to QGIS resulted in no data.

We can get Status activity on the GNSS, sometimes CAN1 activity, and virtually never PPS (even if we take the unit outside).

We have been trying for 2 days now to get the unit to work without success. We were thinking a reflashing of the firmware might be just what it needs.


This could be a manufacturing defect. Let me put you in touch with TitanElite to see how we should go about sending you a replacement board.

That’s ok - I’ve been talking to Nicholas and he knows you and I are chatting here on the forum. He said if you don’t know how to resolve the issue he will replace my unit. Thanks for the help Pavel!

Oh, I just emailed you two before I got to read your last message. Is there any convenient way for you to ship the failed board abroad free of charge for you, e.g. using some sort of cash-on-delivery shipping service? If it causes too much trouble I would understand.