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Sirius XXL GNSS Base Station UART->USB


We have had the Sirius XXL base station for a while now and it has been working great when I use it with a microUSB connector. However, that port is no longer usable since we accidentally dropped the base station while the cable was plugged in and in such a way that the microUSB port on the Sirius completely came off. I have a spare FTDI cable that could convert UART to USB where I was careful in connecting the TX of the Sirius with the RXD of the FTDI cable and RX to TXD. However, when I try to use u-center, I no longer get any messages. It just says “No Fix”. The device is being detected by my computer (albeit the COM* port doesn’t seem to be changing even when I switch the Sirius to different ports on my laptop) but the “COM* 57600” on the bottom bar is not blinking green anymore and I don’t have any print outs on the Text Console.

What am I doing wrong, or is it just not possible to use an FTDI USB cable on the UART port?

EDIT: I’ve also tried to switch the TX with the RX when I connect to the TXD and RXD on my FTDI cable such that I would have TX->TXD and RX->RXD. Even though I would get the blinking green light on the bottom bar for "COM* " and somehow receiving RTCM3 messages (my default when I was using USB), I can’t ever change the baudrate anymore and it just keeps on resetting to 19200, and I’m still getting a “No Fix”. So I don’t believe that this is the right solution.

EDIT2: As a side question, is it not possible to configure the base station without plugging it into the microUSB port? (I read again on the guide that the microUSB cable is needed)

Thank you,

Hello Trixie,

It is totally possible to be connected over UART1 using an FTDI converter.
1- Plug-in the UART converter only, until windows 10 is saying the device is ready
2- Plug in the JST 6 pin cable to the base
3- Open u-center but dont click on the connect button. You need to set the baudrate to the one that was set previously using USB first. To do so, go to “receiver” tab then “baudrate”. Choose 38400 baud to start with.


I hope that all the internal informations were previously set according to what is shown on the right side of the pic above (protocol IN, OUT and baudrate). Otherwise it may not be working.

4- Then try to configure the NMEA MSG in order to gather some satellites data, something should be moving on the right side of the u-center window, at least satellites SNR graph bar.


If not, try different connecting baudrates. (57 600, 115200, etc…)
If it is still not working, maybe the configuration on the right side of the first picture above are not ok. Then there is no way to be connected to your base.

However, if everything is working fine, I suggest you to change the baudrate to the maximum one allowed by your FTDI converter, let’s say 115200 bauds:



Hi Paul,

Thanks for the reply. At which step should I click on the connect button? The baudrate that I was using originally through the microUSB port was 57600, but I tried your advice of starting with 38400 baud and it’s still not working unfortunately. I checked on Device Manager what the FTDI baud is set to and I saw that it was 9600 so I also tried to set the u-center baud to 9600 with no effect. Shouldn’t the "COM " at the bottom bar be blinking green once I click on the connect button if it is working?

Also, here is the PRT configuration I had before, which I somehow cannot change when using UART. Would it be an issue if I don’t have 0+1+5 like on your picture?

Thank you,

Hi Trixie,

Then it should be working using 57600 as baudrate.
You have to click to the connect button after having changed the baudrate settings.
You dont have to change anything under the Device Manager baudrate settings

Hi Paul,

I did try it with the 57600 baudrate, but unfortunately, it still isn’t working. The CFG-PRT window screenshot that I attached is what I always have now whenever I try to click on the connect button but it just doesn’t seem to be connecting at all. At the moment, we will just have to repair the broken microUSB port.

Thank you for the help,

Weird, it should be working.
Try doing the same procedure on another computer. Also you may try swapping Tx & Rx pins, I don’t know the FTDI brand you have, maybe this is the issue.
Try using every baudrates available : 9600 / 19200 / 38400 / 57600 /115200 etc…
Moreover, the screenshot you sent is a non updated overview of the PRT registers, perhaps the register values are slightly differents.
Hope I helped. Please keep me in touch.