New life for ArdusimpleRTK2BLite – UART1-USB + Bluetooth

Q&A forumNew life for ArdusimpleRTK2BLite – UART1-USB + Bluetooth
Mauro Bettella asked 4 months ago

Hello Ardusimple Team,
and a good morning to all ArdusimpleRTK2BLite users
I present my experiences:
I have successfully configured U-Blox ZED-F9P using U-Center
with the configuration file found in this French Open Project CentipedeRTK:
1) RTKLib Windows
I managed to use ArdusimpleRTK2BLite connected to UART1-USB
I followed this guide:
executables downloaded from the following link:
everything works correctly with NTRIP corrections OK !!
2) RTKGPS+ Android (porting of RTKLib version 2.4.3b29d on Android)
Connection with ArdusimpleRTK2BLite UART1-USB all OK!
I have not yet reached RTK fix with the NTRIP Client
– I use a Virtual Reference Station (VRS) and I get a timeout error,
– I must set ambiguity fixing parameters appropriately
– any suggestions about it are welcome !!!!
If I connect ArdusimpleRTK2BLite in UART2-Bluetooth mode
nothing works (UBX messages are missing).
The version of RTKGPS+ available at following link:
does not work if connected to UART1-USB, Application crash ?????
I haven’t solved it yet …
but I think the reason is related to use of
UART1-Bluetooth port of device they use.
I don’t have a similar configuration (UBX messages on Bluetooth port)
so I can’t run any more tests.
Any experience obtained by other users is welcome !!!!!!!
3) SWMaps Android
Now everything works perfectly with UART1-USB connection !!!
SWMaps relies on RTKLib and therefore needs UBX messages
There is still a problem with the decimal separator for the NTRIP Client fix
(my smartphone is now configured in English and NTRIP Client works),
I think the problem can be solved in future updates.
If I use the UART2-Bluetooth connection, missing UBX messages,
– the NTRIP connection is unstable;
– the information of precision and accuracy is missing
the application becomes unusable for my purposes.

4) RtkDroid Android
It is the younger brother of SWMaps has only GNSS part
Some interfaces are similar and certainly it is
from the same SWMaps development team
even if not expressly stated.
The same considerations as for SWMaps apply:
UART2-Bluetooth: receives nothing (UBX messages are missing)

5) LEFEBURE NTRIP Client – Windows and Android
It works great with ArdusimpleRTK2Blite,
is an old application that relies only on NMEA messages
With this configuration I get RTK Fix solutions,
which by enabling ‘GPS Mock Location’ I can use
with QField in a very performing way.
All right!

6) There are other apps which can be used as ‘GPS Mock Location
but some do return for QField
only the latitude and longitude and not the Z
or a transformed Z, it is not known by what criterion.
Any experience obtained by other applications is welcome !!!!!!!
I close this premise and let’s move on to the painful notes.
Connect a USB device to a smartphone
it’s not a good thing, I don’t talk about cables,
an external USB device kills the battery in short time.
All software that uses RTKLib
They DO NOT WORK with ArdusimpleRTK2BLite
if it is connected in UART2-Bluetooth mode (UBX messages are missing)
which decreases the use of Ardusimple devices
if the problem is not solved !!!!!!!
It becomes an important thing, at least for me,
to be able to use ArdusimpleRTK2BLite
with UBX messages enabled on UART2 port
or alternatively
move the Tx and Rx signals of UART1 (XBee USB, which already has UBX messages enabled) to the current XBee Bluetooth.
This should be feasible by reading these posts:
I found this device at this link:
USD 85 + USD 10 shipping
I have not investigated deeply but it should be an Arduino
with some software installed for the GNSS part ????
which transfers the signal received on USB to the bluetooth port
It seems to me an extreme remedy for using Ardusimple
which is already Ardu …
this opened my eyes
and I had this idea …..
I think ArdusimpleRTK2BLite modification
is easily done!
XBEE-USB already has the pins that can be used for a Bluetooth output,
to which a bluetooth device could be connected
like HC-05 or HC-10 or something similar.
Idea would be to solder a 90 ° female angular connector
to back of XBee-USB board
and directly connect an HC-05 Bluetooth
connectors are already in correct position !!!!!
I think ArduSimple development team
has resources and professionalism
to solve this simple problem:
UART1-USB + Bluetooth !!!
What do you think?
I personally have no knowledge of electronics
– I don’t know Arduino
– I don’t know if HC-05 needs some configuration / setup
– there is already something in the French project CentipedeRTK:
I launch proposal for this change to all users,
I hope for a positive response

Ardusimple Staff replied 4 months ago

Thank you Mauro for sharing your experience with the community!

4 Answers
Mauro Bettella answered 4 months ago

Update for RTKGPS+:
I installed Alpha2 version (U-BLOX ZED-F9P):
Configuration RTKGPS+:
Input streams –> Input base –> NTRIP Client
with VRS virtual reference station, enable:
Transmit GPGCA to Base Station –> Single solution
Processing options –> Integer ambiguity resolution settings
follow these indications:
Connect simpleRTK2BLite
with USB-UART1 – UBX messages enabled!
(no Bluetooth-UART2)
Everything OK:
RTK float and RTK fix solution !!!
Any idea to connect Bluetooth HC-05 to USB-UART1?
Thank you

dsgeo57 replied 4 months ago

SW_map work fine, the only problems is that you need to set English language on android settings. If you don’t set, RTK status rest to “single”.

amorosik answered 4 months ago

Have you already tried with the classic four-wire connection Vcc, Gnd, Tx, Rx and verified that it does not work?
Are you sure that the TX pin of the HC-05 module is the signal coming out of the module and not vice versa?
I say this because for example on the Sparkfun Bluetooth Mate module the pin marked as TX is actually an input for the module
I see you operate in the Venetian territory, if this were the case we are also geographically close
Can you leave me an email or other reference for an exchange of experiences on these topics?



Mauro Bettella answered 4 months ago

I’m not an electronics expert,
which is why I asked the forum
and Team Ardusimple!!!!!
The idea of the HC-05 Bluetooth module
to connect to simpleRTK2BLite
came to me watching the French open project Centipede,
particularly this image:
I took courage and I connected the four wires…
I configured HC-05 Bluetooth
with baud rate at 115200,
because the connection
is a module with USB output.
I’ll run lower baud rate tests…
Of course Team Ardusimple
could give directions on this!!!!

Mauro Bettella answered 3 months ago

Important update for SW Maps:
The SW Maps developers have confirmed to me that their software
use the RTK model integrated in the ZED-F9P receiver !!!!!!
(I wrote that it uses RTKLib, it’s not true)
It is very important to have a good configuration
of the receiver with U-CENTER !!!
With the recent version 2.6.5 it works perfectly
USB (UART1) and Bluetooth (UART2)
English and Italian language (dot and commas problem
solved !!!