Newbie question about using a Lora link to send RTK/SSR connection to a standalone simplertk2b

Q&A forumCategory: QuestionsNewbie question about using a Lora link to send RTK/SSR connection to a standalone simplertk2b
matt3003 asked 3 weeks ago

Hi.
I just ordered a standalone simplertk2b – I should receive it in a few days and I am very excited.
At first I intend to use it as a simple GPS – later maybe buying another one to move to a base / rover config.
My question is this : I already have several Lora modules, and I was wondering – can I transmit from my home the RTK/SSR corrections (that I would get from the internet from one of the NTRIP services) to my simplertk2b using a Lora link ? (I would send the corrections from home, and then use them on my mobile unit).
I know it should be theoretically possible, but I’m not sure how – My “mobile unit” is gonna be based on a arduino UNO, with a Lora shield, and I intend to add the simplertk2b on top of it. (Btw I am not 100% sure if I will need a logic converter – I saw somewhere that I would, but the specs say that “UART voltage levels are adjusted automatically based on power source voltage” so I guess I’m good ?)
Is it as simple as feeding the received corrections, without any processing, to the ZED-F9P ? (I’m guessing using its UART2 ? So simply sending the corrections to UART2 RX ?) That’s it ? It will know it’s corrections and try to use them ?
I’m barely starting experimenting with GPS’s, I’m still new to all of it (I’m not even sure what a NTRIP “packet” contains yet)
Thank you in advance.

2 Answers
matt3003 answered 3 weeks ago

(sorry about the error in the title of the question – I meant “send RTK/SSR coRRectionS“, not “coNNection”)

clive1 answered 3 weeks ago

The SimpleRTK2B boards use IOREF pin on the shield, using them with 3.3V boards here.
Specifically the STM32 LoRa DISCO board as I can use both serial ports if I remap the debug output.  https://www.st.com/en/evaluation-tools/b-l072z-lrwan1.html
The RTCM3 data can be injected in either UART1 or UART2, the latter might be easier if you’re not managing the packet boundaries and just shoveling data into the interface.
The board is good fo me as I can program the CPU and it has enough horse power to manage the LoRa radio layer, two ArduSimple boards, a 2.42″ OLED display, and do a bunch of packet handling and floating point math.
Mind you this *isn’t* using LoRaWAN but rather the LoRa radios in a point-to-multi-point configuration.