Let me start by saying this is my first post as I am at the very early stages of learning about GPS & Radio/LoRa so if my questions don’t make sense please let me know as this is the only way I will learn…
I am looking at buying the SparkFun LoRaSerial Kit - 915MHz (Enclosed) to transmit RTK Correction Data between a static Base Station and a Rover in my Tractor. I would probably also upgrade the antenna in your serial kit at the base station to the LoRa Fiberglass Antenna Type N - 5.8dBi (902-928MHz) & the Interface Cable N to RP-SMA Cable - 1m (the Antenna to be mounted on a pole at the shed for the Base Station connected to SparkFun LoRaSerial Kit (set as transmitter) which would be connected to the Ardusimple simpleRTK2B board acting as Base Station to transmit the RTK Correction Data to the Rover/Tractor which would also have SparkFun LoRaSerial Kit - 915MHz (set to recieve ) plus another Ardusimple simpleRTK2B board.
I have 3 questions:
- Given the terrain & trees detailed below should I be concerned that the SparkFun LoRaSerial Kit would not be able to communicated between the transmitter and receiver?
- Will the SparkFun LoRaSerial Kit work work with the Ardusimple simpleRTK2B board to transmit the RTK Correction Data ?
- Is there anything else I would need to buy to improve the reliability or connectivity of this proposed setup?
Terrain Details for Context:
The Farm is located in NSW, Australia not big (only 100 Acres) so the furthest distance between the Base Station and Tractor/Rover would be ~700m but hilly with trees.
I have used the line of site elevation tool (Solwise - Surface Elevation Tool | Solwise Ltd) below to give you an idea of the terrain to get an opinion before buying the extra items if you think it would work using static base station located at the Shed located at the Blue Pin on the screenshot vs the rover located at the two locations shown below by the 2 Red Pins and their respective Line of Site Elevation Profiles. (see below)
I am hoping that given the distance is less than 1km that the trees and terrain will not cause enough interference to mean the Tractor/Rover would not receive the correction data.
Below are 2 furthest points the Rover/Tractor (Red Pin) could be from Base Station (Blue Pin)
In my experience with 915MHz-band radios, you pretty much need line of sight, and dense trees can block the signal. So get that base antenna up high!
I don’t know what the legal bands are in Australia, perhaps you need radios with different frequencies?
Consider externally powering the radios. Check the specs on the Facet radio port and compare them with the power requirements to run the radios at full power (1 watt).
I’ve tried three sets of 915MHz radios - the 100mW Holybros from Sparkfun, the 1W RFD-900x radios, and the 1W SparkFun LoRaSerial radios. I did not run a controlled experiment but I have had better luck in my unique situation with the RFD-900x radios. They are made by an Australian firm (https://rfdesign.com.au/) so they might be easier for you to source. You might need to to build your own cable, I frankensteined a couple commercially available cables together to make cables to connect my Facets to the RFD900x.
My understanding is that the radios Ardusimple sells are low powered so they don’t seem to be an option.
Thanks @toeknee for the response, I am hoping to install the SparkFun LoRaSerial Kit - 915MHz (Enclosed) with the Base Station using the LoRa Fiberglass Antenna Type N - 5.8dBi (902-928MHz) installed 3-4m off the ground on a pole off the shed roof… hopefully that works.
I have gotten confirmation from ArduSimple that you can use the SparkFun LoRaSerial Kit - 915MHz (Enclosed) with their simpleRTK2B GPS/GNSS RTK boards but you will need to play with the configuration, as their boards configuration files expect radios on the UART2, and while the SparkFun Lora radio will likly be connecting on UART1… Not sure what that means but sure the iternet will help me out.
Once I get this all sorted I will post a video of my journey to get RTK precision location in my tractor…
One last thing… I love SparkFun but how can it cost $311 to ship the LoRaSerial Kit & LoRa Fiberglass Antenna to Australia??? I know we are a long way away and all but there has to be a more cost effective way to shipt to Australia so we too can share in the SparkFun joy!.. I am now having to ship to a friend in the US and they will send it on.
@sparkfun please make this better for next time.
toeknee has good advice, I’ve heard good things about the RFD-900x radios, An Alternative is getting the 500 mw holybros. Source them from wherever is convenient. Steer away from the LORA’s. Also, the farther you try to send a signal, the less data you can send (aka correction rate). If you have good cell coverage you could consider rtk2go,
We have Australian Distributors…https://core-electronics.com.au/
@TS-Russell Thanks for the pointer to local suppliers, unfortunately they are out of stock as is the other supplier www.robotgear.com.au so am back on the search.
