Basic Base/Rover config, hard wired, for novice.

Q&A forumCategory: QuestionsBasic Base/Rover config, hard wired, for novice.
glenn.littleford asked 2 months ago
I have a couple Ardusimple RTK2B boards, one for a rover and one as a fixed base. I’ve wired the grounds together, and the TX1 brom the base to the RX2 of the rover, plus set the v-ref pin to 3.3 on both, and they are running firm ware 1.32.
I installed the Base config file on the Base board, and the 1Hz rover file on the rover board. I can see with a CRO the Base is sending serial data out every second.
The Base stays in 3D mode, not Time, even after 30 minutes. Its picking up about 40 satelites. So I tried fixing the Long/Lat for the base under TMODE3. It now goes into TIME fix.
But the rover stays in 3D fix. Its PRT UART2 is set to protocol in 0+1+5 UBX+NMEA+RTCM3. Checked baud rates. The No RTK led is staying lit. Need a little help.
replied 2 months ago

On the Arduino Rail the TX2 pin is the INPUT
You don’t want to get a kitchen sink of data into UART2, you ONLY want the RTCM3 messages.
This might be simpler if you used UART2 on the BASE and the ROVER
IOREF = 3.3V

1 Answers
glenn.littleford answered 2 months ago
Thanks. I ended up using the xbee Rx and Tx lines, UART2. Changed the PRT-UART2 Protocol in on the Rover to 5-RTCM3 and the Base UART2 out to the same. 
On the Rover after about 10 minutes I get a fix of 3D/DGNSS/FLOAT, so I assume the base is sending RTK info and the Rover is receiving and processing it ?
It never gets to a FIX state. Both receivers are mounted in a window facing outside to a clear sky, and I see about 40 satelites, a mix of GPS, GLONASS, QZSS, Galileo and BeiDou.
Surely I should be getting a fix. Looking at the Deviation map ( u-center ), its all over the place within a couple meters.
I think I’m missing a setting somewhere?
replied 2 months ago

Out of a window, with building masking half the constellation, yes probably going to stay in Float forever.
Ideally Base has a 360 degree view to the horizon.

replied 2 months ago

Bingo! You were right. I took it out into the yard with my laptop to power them and got a fix within 1 minute. Rock solid. Moving the rover antenna around was mimicked on the screen, and returned back to start position within a centimeter. Thank you. Now I’m just waiting on a couple RF serial modules to arrive and I can move forward with the project ( lawn mower ).

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