with the SparkFun Triband GNSS RTK Breakout - mosaic-X5, if the goal is to simply use the Mosaic-X5 web interface over Bluetooth from Android, can a HC-06 board be wired to COM1 along with appropriate power/antenna/configuration? Am I oversimplifying?
That should work fine, but the BlueSmirf is our official recommendation 
Thanks for sanity check!
Hi Grif (@gnewcom ),
Can I just check what you mean by “web interface”? Do you want to be able to access the X5’s internal web page from your Android phone? Or are you happy with just a COM port for the command interface (serial data)?
A BlueSMiRF will get you a simple ‘terminal’ connection to the COM port. If you open a Serial Terminal App, you’ll be able to send commands and see the results. The X5 COM ports do not output NMEA by default. Hit ‘Enter’ in your Terminal App and you will see the “COM1>” prompt. You can then type commands and see the results. The X5 COM ports default to 115200 baud, and so does the BlueSMiRF v2, so you don’t need to worry about baud rate changes. You can set up a stream on the same COM port if you want to see NMEA. Edit: Once the COM port is outputting NMEA, Apps like SW Maps will be able to use that data to display and log your position. But that may be of limited use if you don’t have cellular coverage… (What you really need is an App that knows how to talk to the X5 using its command interface, but there doesn’t appear to be one.)
If the X5 web page is what you’re after, you need a different solution. You can only view the web page if you are using full Ethernet, or Ethernet-over-USB. The X5 Breakout doesn’t have full Ethernet, you are limited to Ethernet-over-USB. It’s big brother, the RTK mosaic-X5 does have full Ethernet, and also has an ESP32 which can convert Ethernet to WiFi. I haven’t tried connecting an X5 directly to an Android phone. I’m assuming that’s possible with USB Tethering and/or an On The Go (OTG) cable. I’ll order some and give it a try.
I hope this helps - and doesn’t create more questions than it answers!
Paul
Paul, thats exactly the detail I needed. So a com port works for CLI or NMEA out, but can’t be used for X5 web interface. I’m looking for some limited configuration capability in the field with Android tablet, sounds like this needs usb tether.
Hi Grif (@gnewcom ),
You can do everything the web page can do over a COM interface. But you have to do everything manually, command by command, and you don’t get the pretty user interface…
I’ve ordered a couple of OTG cables - they’re arriving tomorrow. I honestly don’t know if Android phones (or tablets) support Ethernet-over-USB, but I’m going to give it a try…
The X5 is a fantastic module. Internally, it’s a fully-featured embedded computer. There’s very little it can’t do. But it is costly. The Postcard may be good enough for you, especially if you’re on a limited budget.
Let us know how we can help,
Paul
Hi Grif (@gnewcom ),
A partial update for you:
I’m experimenting with an old Samsung Galaxy Note 8. I’m using a USB-C → USB3 OTG adapter plus a regular USB2 cable to connect the phone to the mosaic-X5 Breakout USB connector. The phone is powering the mosaic successfully, and the mosaic has a fix. The “Serial USB Terminal” App is able to detect and open the USB1 and USB2 virtual COM ports. But, more importantly, SW Maps is also able to connect and - to my delight - is Mosaic-aware, can configure a stream of NMEA to the same COM port and display my position:
Closing SW Maps and returning to Serial USB Terminal, there is now a stream of NMEA on USB1:
I haven’t yet found a way to access the Ethernet-over-USB and the X5’s web page, but I’m hopeful because SW Maps is detecting the interface. It is Interface 1 in the above screenshot. (Interface 3 is the USB1 virtual COM port; Interface 5 is USB2). Serial USB Terminal detects them as “Serial device - CDC Port 1 … 3”; CDC 1 is the Ethernet-over-USB port.
So, more work to do. I won’t be happy until I’ve found a way to access the web page…! 
Best wishes,
Paul
Does the Galaxy Note have a “USB tethering” option in settings? I read somewhere that this was how to do web connect via USB. Thanks much for the followup. I’m out of US for a week, no rush on response.