Hello everyone,
I'm currently working on a project that requires establishing a non-line-of-sight wireless communication link with a range of 1km or more, without relying on the internet. I'm looking for guidance on the best transmitter and receiver options, as well as any tips or tricks that can help me achieve this.
Thanks in Advance.
I moved your topic to an appropriate forum category @vara-prasad.
In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.
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Thanks in advance for your cooperation.
Maybe this is of interest to you?
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Might work, but under non line of sight you'll never know until you try it.
Will LoRa can effectively work on Non - LOS conditions? If we use a LoRaWAN it requires internet connection right so, how to overcome this? Suggest me any LoRa modules for the 865- 867 MHz range.
Hello vara-prasad
Welcome to the worldbest Arduino forum ever.
Take some time and visit your local amateur radio club to discuss high frequency, antennas and propagation conditions.
Have a nice day and enjoy coding in C++.
yes under certain circumstances that is possible.
Explain in more detail your use case.
I need to control two stepper motors over the 1Km distance. I don't know how many bytes it require. We will use this communication whenever we require it mostly a hour. We are going to use this transmitter and receiver mostly in free nature and urban villages.
Thank you
if you don't know the payload right now, make assumptions. Calculate the worst case.
Don't start a Lora project without knowing your exact requirements. Otherwise you can't check if your used airtime will fit to the regulations of your country and your system might become illegal.
Okay. Then LoRa won't be suitable in my conditions. So, is there any other alternatives? And these rules still apply on node to node communication because we don't want to upload it in TTN servers. we just need to control stepper motors over the distances.
Yes, but it depends on what is blocking the line of sight. Buildings, trees etc will significantly reduce the range of the signal. No one can tell you if you will get 1KM, the only way to know is to try. Hills and mountains will block it completely, so relay transmitters will be needed to get around them.
Correct, if there is no internet, LoRaWAN can't be used. But it may be possible use multiple point-to-point links to get the signal through.
RFM95 modules are commonly used with arduino and are available in 868MHz.
Please explain how you know this.
Thank you for the detailed answer. We don't want to use internet in this project it will be directly point to point communication. will RFM95 works in Non - LOS conditions over 1Km range?
See previous answers given.
I require remote control of stepper motors over considerable distances. If we operate the motors continuously for an hour, it could result in a significant increase in uplinks and downlinks. I am considering whether this might exceed the airtime limit. Furthermore, I want to emphasize that I intend to achieve node-to-node communication without relying on the internet. Do these rules still apply? These made me think that LoRa will not work in my case.
Without knowledge of what these stepper motors are doing, we cannot help you estimate how much data and what rate of data would be required.
Wi-fi could be another alternative. Wi-fi uses higher frequency than LoRa which reduces it's range even further, especially in non-LOS conditions. Directional antenna such as the Yaggi designs can increase it greatly over simple dipole designs. Wi-fi has much higher data rates than LoRa, but transmit power will be limited by local regulations.
There is no requirement of higher data rates. We are using Pan and tilt stepper motor mechanism. Thanks for your insights.
But what is being panned and tilted? How will you know, from the remote location, if the object is panned and tilted to the desired direction?
I have done a very significant amount of range testing with LoRa, set some of the distance records with it etc.
You are making a fairly classic assumption that for your unknown location and unknown environment someone can tell you if a particular type of communications will work, but that is just not possible due to the vastly different locations and environements.
LoRa is the longest range type of comms that you can legally use, if that wont work, then its likley nothing else will.
As several people have mentioned already if you want to know if LoRa works for you then you have to try it, end of.
Here are some practical tests, with pictures, so you can see the location and environment;
If its practical to have intermediate devices, then its not difficult to set up LoRa devices as relays and there are mesh setups too.