LoRa increase distance

Projects Programming
1

I am using LoRa Ra-02 and arduino uno and this library.

how will I know what values should I use to maximize the distance. I am working in area with so much houses (not much an open area).

In my testing, I only get a few meters (less than 100 meters) and the RSSI is at -30 to -80.

I am also using 12dBi whip antenna for both my transmitter and receiver node.

// LoRa.setTxPower(20);                   // Supported values are 2 to 20
// LeRa.setSpreadingFactor(12);           // Supported values are between 6 and 12
// LoRa.setSignalBandwidth(62.5E3);       // Supported values are 7.8E3, 10.4E3, 15.6E3, 20.8E3, 31.25E3, 41.7E3, 62.5E3, 125E3, 250E3, and 500E3.
// LoRa.setCodingRate4(8);                // Supported values are between 5 and 8, these correspond to coding rates of 4/5 and 4/8
// LoRa.setGain(6);                       // Supported values are between 0 and 6
2

There are 27 dBm Lora modules. Use a directional antenna.

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3

Many such antennas have exaggerated gain specifications. Pay close attention to your antenna quality. Use yagi antennas on both ends.

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4

free line of sight

is the factor with the biggest impact on range.

Andreas Spiess made an attempt for a world-record-distance
I don't remember which Lora-Mode had the bigger distance
SF12 or SF 7

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5

Sounds exaggerated. Is it designed for the correct frequency?

Please post a link to this antenna.

6

Antenna "gain" is achieved by concentrating the radiation pattern in specific directions. A "whip" antenna is omni-directional, meaning it transmits and receives equally well in ALL directions. Therefore, it cannot have gain. A dBi gain is from a mathematical formula, not real life. The best you can get from any whip antenna is 0dB or 3dBi.
Either you misread the document or the seller lied to you.

To get better distance, you need antennas the concentrate the signal to a single direction. But in the area you describe, you actually need to test the path before you invest time and money in a project based on an assumption that it will work.

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7

People get 40 km range using a piece of wire as an antenna on LoRa radios.

Clear line of sight is the key, not the antenna.

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8

I read your linked report. The OP has none of that equipment, nor the LOS conditions. He needs to personally test his communication path with his equipment and modify stuff until he either gets reliable communication or finds another project.

9

The OP claims to have the RA-02 LoRa radio module, which contains the SemTech SX1278 module, used for the range tests in the report I linked.

10

I can't recover the link of the shop but here's a similar item

image
image800×800 105 KB

I am not really knowledgeable on antenna, thank you so much I am learning I should have ask here first before buying anything.

And also is there vertical clearance requirement or a free line of sight is enough?

As for the lines of code above, is it still necessary to use those codes when I already have free line of sight?

By the way I am sending 33 packets in total and I haven't tried to check the SNR (I honestly have no idea what SNR is and how to use the following codes above. i just thought that it might improve the distance of lora aside from changing antenna).

11

Go through the studies linked in post #7 to learn more about selecting parameters to optimize LoRa range.

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12

The pictured antenna is not a "whip" antenna. It is a multielement vertical antenna with some amount of gain. The most gain is when it is mounted on a huge ground plane, the automobile! Yes, the dBi listed is possible with the antenna and the car body as shown. But cannot be applied to any other configuration.

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13

Is the Whip antenna tuned for the correct frequency?

14

Good point. For fun, I placed a cheap imported magnetic mounted whip on the fridge, and examined the impedance from almost zero to 1GHz. It didn't resonate on any common frequency band at all. That means it is basically only useful as a receive antenna, and not even a very good one. Vendors often make up creative specifications about what frequency it operates on. Either, because it will make a sale, or just because they actually have no idea. They will just say, "433 MHz" because it will get more hits.

The image in reply #10 is an example of seller shenanigans. The antenna has a magnetic cup mount but in the image showing the car, it is on a trunk "lip mount". It also appears longer. That suggests it must be a different antenna.

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15

I got a little busy on holiday break but I'll make sure to read on and study everyone's suggestion. thank you for answering here I really appreciated everyone!

16

Range of lora module is depend on Antenna and obstacles in the path of communication,
If you have to increase the range of of communication so you need to straight line of site and no obstacles in the path

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17

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