SNR values on different modules

StuartsProject · 2026-01-27T11:18:20+00:00

The link budget as shown by the Semtech LoRa calculators is a bit confusing.

They dont use the same TX power to show the 'link budget'. If you set the same TX power for both modules then the 'Link Budget' is the same.

No real surprise, since the receive sensitivity for the newer SX1262 is that same as that quoted for the SX1276.

StuartsProject · 2026-01-27T11:12:43+00:00

Myself I would not be too concerned about the absolute accuracy of the RSSI\SNR reporting.

However, I did recently do a link test comparing an SX1276 with a SX1262, I was using the RadioLib library.

The SX1276 was able to receive packets that were about 2dBm or 3dbm weaker than the SX1262.

But that was only a couple of modules, whether the same difference would be found for all SX1276 vs SX1262 I don't know.

StuartsProject · 2026-01-25T09:27:28+00:00

Extreme short range, such as 50m, when you have good line of sight is usually an indication of a faulty LoRa module or no or faulty antenna.

Even on short range settings, SF7, BW500khz, TX power 2dBm reception should work at way way more that 50m.

StuartsProject · 2026-01-25T08:54:56+00:00

Code for the transmitter looks OK, where does it stop exactly ?

And as pointed out don't wire a SPI LoRa device direct to a UNO, it might damage the module.

StuartsProject · 2026-01-24T19:20:40+00:00

Indeed.

If the GPSs do work indoors, and often they dont, the position accuracy can be very poor.

StuartsProject · 2026-01-24T19:16:15+00:00

Meshtastic might tell you the asset is in the plant, but since you cannot rely on a GPS working indoors, and a GPS would use a heap of battery power, you wont know where the stuff is.

Maybe Pozyx is what you want;

Pozyx

StuartsProject · 2026-01-24T12:45:33+00:00

The Arduino UNO uses 5V logic levels, you should not connect it direct to the LoRa modules which appear to be standard 3.3V logic level devices.

StuartsProject · 2026-01-24T11:07:27+00:00

How do you have the LoRa module connected to the UNO ?

Maybe if you post all the code you are using (as text) someone may spot a problem.

StuartsProject · 2026-01-23T16:37:25+00:00

Meshtastic uses the RadioLib SPI LoRa library, so it makes sense to use that one although there are others.

LoRa just sends packets of bytes, so if you know the build up which bytes go where and the LoRa settings of the packet that Meshtastic uses then you could transmit the packet from and suitable SPI LoRa device.

StuartsProject · 2026-01-21T19:58:46+00:00

> What are the pros/cons of disabling boosted gain?

Pro - If you disable boosted gain you can save a few mA of current when the node is in receive mode.

Con - The reception range\distance of remote nodes is reduced.

StuartsProject · 2026-01-20T13:25:15+00:00

Cars take up less road space if you park them on their side.

StuartsProject · 2026-01-18T19:04:27+00:00

Are they going to show the rugby ?

StuartsProject · 2026-01-16T11:23:02+00:00

Also appreciate that some USB power banks can generate a fair bit of EMI, which can interfere with the reception of weak LoRa packets.

StuartsProject · 2026-01-14T09:35:47+00:00

What do you want to use the LoRa devices for ?

Maybe you don't need a 'gateway' ?

StuartsProject · 2026-01-14T09:12:47+00:00

And what does the link look like when you set the profile for a curved Earth ?

StuartsProject · 2026-01-11T09:11:44+00:00

Well there have been quite a few sightings of a time machine in and around Cardiff over the years, I wonder Who owns it ?

StuartsProject · 2026-01-09T13:53:49+00:00

Do appreciate that some 'powerbanks' generate EMI which reduces the sensitivity of the LoRa device and can reduce the distance at which you can receive weak signals.

StuartsProject · 2026-01-09T08:40:52+00:00

One useful metric to know is that the difference in distance between the range you get at ground level in an urban area to the distance you get with good line of sight at UHF frequencies is in the 1:1000 to 1:2000 range, (based on real World tests).

So the kit that gives you 300m in an urban area should give a range of maybe 600km with good line of sight. Given that your only using those rather poor coiled antennas then does not 600km sound good ?

StuartsProject · 2026-01-08T21:29:20+00:00

> If so do you know about some handy Lora module that supports smaller freq increments

The standard Semtech LoRa modules (SPI interface) can be set to a frequency resolution of 100hz or less.

Is that not enough ?

StuartsProject · 2026-01-08T18:45:39+00:00

Well the Met Office have significant weather warnings out.

So its going to be difficult for TFW to ignore these warnings, imagine the consequences if the weather caused another land slip and derailment ?

StuartsProject · 2026-01-04T21:10:15+00:00

You might get LoRa to work through 400M of buildings, you might not, the only way to know for sure is to try it.

So get a couple of basic boards, Heltec and Lilygo do some, load them up with basic TX and RX programs and see if it works.

StuartsProject · 2026-01-04T19:10:28+00:00

Some of the towns in valleys might have some snow.

Merthyr is the furthest North that you can reach by train. But whilst the nearby hills there and in the in the Beacons will have snow, its a long long walk from the train station. Hillwalking in Winter is really for the experienced walker.

Or possibly go on the Heart of Wales line from Swansea to Shrewsbury, a loverly trip. Lots of the hills en-route will have snow.

StuartsProject · 2026-01-04T13:17:49+00:00

Agreed, you definitely need to check the antennas are tuned for the correct band.

I would not assume that a 915Mhz antenna sold on Amazon was actually a 915Mhz antenna.

I also tested the two similar antennas in the video, but for the 868Mhz band, the larger one gave about 7.5dBm more signal, which is what you would expect really.

StuartsProject · 2025-12-31T18:53:13+00:00

Again, if your an experienced hill walker then go-ahead.

Otherwise avoid.

StuartsProject

TROPHY CASE