RTK Express Plus not working after u-blox firmware upgrade

I just received a brand new RTK Express Plus. It worked fine until I upgraded the u-blox firmware. The U-Center firmware upgrade process went well, and U-Center informed me that it was successful. I can still connect the unit to U-Center and look at receiver configuration info.

However, now there seems to be a problem on the ESP32 side of things. Shortly after the ESP firmware version is displayed, “RTK Express+ v1.6”, the display shows “GNSS Failed” and the unit becomes unresponsive. The following output appears on the ESP32 USB-serial port and then the serial port disconnects.

ZED-F9R firmware: HPG 1.32

Version 1.6 of the ESP firmware seems very old to me. I’ve been running version 3.2 on other RTK Express devices. If I were to speculate about the reason for my problem, I’d say the ESP firmware is having trouble communicating with the latest u-blox firmware. Unfortunately, I can’t access the ESP serial port and I can’t turn the wifi AP on, so I have no way to upgrade the ESP firmware. Does anyone have a suggestion?

I went thru The same, and i was able to Reflash both Esp 32 And the ZED. The unit came back to life, could detect satellites, and be usable as a rover or base, but since then, issues remained. When i entered Wifi config, make a change, and save, at restarts always says GNSS failed, and takes several restarts to come back. Also The Battery Icon goes From full to empty (just the icon) the units remain operating an the screen freezes sometimes. I’m not complaining, now is fixed by Sparkfun Hopefully you can fix yours at 100% by yourself, i tried. Oh and i want to mention just 1 unit did this to me, the other (i have 2)updated with no issues, both ESP and ZED.

Hi,

The Express+ uses the ZED-F9R module - which needs HPS firmware. The latest is HPS 1.30. The HPG (1.32) firmware is for the ZED-F9P - used on our other RTK products. Please try reprogramming the F9R and let me know if you need more help.

TLDR: the older versions of the RTK firmware used version 2 of the SparkFun u-blox GNSS library. As the GNSS module firmware was upgraded and improved we had to switch to version 3 of the GNSS library, which detects and configures the modules in a different way. The old RTK firmware won’t necessarily work with the new GNSS module firmware. I’ll try some tests here just to confirm. But I was successful in upgrading an Express+ - both RTK firmware and GNSS firmware - earlier this week.

Best wishes,

Paul

Just documenting this as I go:

Starting with RTK Firmware 3.3 and ZED-F9R firmware HPS 1.30

Downgrade RTK Firmware to 1.12

Turned unit back on again. All is well. GNSS detected and receiving signals

Turn unit off again

Switch to the u-blox port

Turn unit on again

Downgrade GNSS to HPS 1.20

Turn unit off and on again. All is well. GNSS detected and receiving signals

Turn unit off

Switch to the ESP port

Turn on again

Upgrade RTK firmware to 3.3

Turned unit back on again. All is well. GNSS detected and receiving signals

Turn unit off

Switch to the u-blox port

Turn on again

Upgrade GNSS firmware to HPS 1.30

I’m using our u-blox update tool. Turning on Packet Dump shows the update progress

Turn unit off and on again. All is well. GNSS detected and receiving signals

OK. That has all gone well. I was worried that the old RTK firmware might not be able to detect the new GNSS firmware, but it seems to be working just fine.

Best,

Paul

Just an FYI:

If you are using our u-blox update GUI, it checks the module type before doing the upgrade, so you can’t put the wrong firmware onto the module (unless you tick the Override box!). It’s here if you need it: https://github.com/sparkfun/SparkFun_RT … Update_GUI

Packet Dump will let you see the update progress - like u-center just not as pretty.

Thanks for the responses. I did have the wrong u-blox firmware installed. I used u-center to revert to F9R firmware 1.20. Upgrading the RTK firmware wasn’t so easy. I pulled my hair and gnashed my teeth for an hour or two before I got it done. Here’s some more detail about that in hopes that it helps someone else:

The unit came with RTK v1.6 installed. I would have gone straight to using the serial console to do the upgrade, but every time I connected the ESP32 USB port to my laptop the RTK Express shut down. Without the console, I had to turn to the wifi and SD card firmware upgrade mechanisms and none of them worked for me. RTK firmware 1.6 doesn’t seem to support the wifi upgrade mechanisms. I tried upgrading from an SD card through the RTK Setup webpage and through the force upgrade method and neither worked. I thought force upgrade from an SD card was going to save me, but when I booted the unit with the SD card in it, the display said “Force Upgrade” for about a second and then switched to Rover mode. No upgrade happened.

Finally, I figured out that my serial console problem wasn’t caused by firmware but was a hardware issue. If my RTK Express is running on battery power, then it shuts down as soon as I connect the ESP32 USB cable to my laptop. If the RTK Express is running on wall power then it stays running and I can use the console. At that point, I was able to use the RTK Uploader executable to do the upgrade. The unit’s battery was 90% or more charged so I don’t think that was the issue.

Based on this experience, I’d like to make a suggestion to Sparkfun. I’ve bought four expensive RTK units in the last few weeks and only one of them had recent firmware installed. The old firmware was so old, <= v1.6, that there were u-blox/RTK version compatibility issues, and it was hard for me to successfully upgrade because my firmware version didn’t support many of the documented upgrade mechanisms. I think all of the units should be shipped with relatively recent firmware that has all of the features described in the documentation.

My problem with the unit shutting down when I connect the USB cable needs to be fixed, or the workaround should be documented in big bold letters.

Apologies for the inconvenience - and thank you for the detective work. The RTK firmware is developing quickly and we keep adding more features. It is difficult for us to update product which has been manufactured, tested, programmed, packaged and put into stock. But I will pass your comments along to the team. I’ll also try and add better instructions to the online product manual.

Best wishes,

Paul