Need help with range issues using Meshtastic on RAK4630 modules on 433MHz frequency

Good day everyone!

My dad and I are currently trying to experiment with a Meshtastic deployment in our city for remote weather/environmental monitoring as well as text communication over radio for emergency/natural disaster scenarios, since the area we are in is prone to flooding, landslides from typhoons as well as earthquakes.

We went with the modular system of RAKWireless, all built around the base of the RAK4630 module on the 433MHz frequency (we both have licenses to operate this band). Installation of the Meshtastic firmware was easy and painless, and so was connecting it over USB to the Web UI or over Bluetooth with the Android app. Sending messages along with position and sensor data between multiple modules within various points in our house went by smoothly. So we proceeded to try using them at distance.

Since this is an urban environment with lots of interference and interruptions to line-of-sight, we didn’t expect to get range above a few kilometers, much less the dozens and even over 100 kilometers that I’ve seen some users achieve here. But we are just barely making it past 100m or a single block, even with relatively clear line-of-sight. We’ve done multiple tests on multiple antennas, from the stock one included with the RAK4630, to telescopic ones similar to those small AM/FM radio sets, to small whip antennas specifically for 433MHz, to large stationary antennas that we use for other HF/VHF/UHF radios both at our house and on a station we have in the mountains next to the city, all with and without an attached filter.

This is unusual behavior for this frequency and the support at RAKWireless agree, though they could not provide any support specifically with the Meshtastic firmware. So I am here hoping that perhaps there are others here that have experience with this problem and/or the RAK hardware. For reference, we are using the default values set by Meshtastic, apart from setting the region to EU433.

Thank you in advance for reading through and giving this consideration.

Hi JulesDR, the issue you’re describing seems to be very similar to the one I’m also trying to debug over in that thread:

(Currently, I’m trying to understand more about how RadioLib is used in the Meshtastic firmware, I suspect that the issue is related to that.)

Have you already tried to run the RAK LoRaP2P Arduino examples? They work well on my RAK4630s, with the default settings from the examples I get RSSI/SNR values like this (in UART logs), with sender and receiver at a distance of about 1 meter:

RssiValue=-16 dBm, SnrValue=13
RssiValue=-16 dBm, SnrValue=13
RssiValue=-16 dBm, SnrValue=13

And with these slower settings…

#define RF_FREQUENCY 868000000 // Hz
#define TX_OUTPUT_POWER 22 // dBm
#define LORA_BANDWIDTH 0 // 9  // [0: 125 kHz, 1: 250 kHz, 2: 500 kHz, 3: Reserved]
#define LORA_CODINGRATE LORA_CR_4_8   // [1: 4/5, 2: 4/6,  3: 4/7,  4: 4/8]

…I get this:

RssiValue=-13 dBm, SnrValue=7
RssiValue=-13 dBm, SnrValue=7
RssiValue=-12 dBm, SnrValue=6
RssiValue=-16 dBm, SnrValue=7
RssiValue=-14 dBm, SnrValue=6
RssiValue=-12 dBm, SnrValue=6

can you update to firmware 2.0.13 and try again? there’s a potential fix for the power issues in there.

Was just about to post as well. That’s what this comment on another thread is saying. Remote Node Administration does not work, somehow - #27 by SR7673

Thank you very much for the replies and links, rgj, caveman99, and crichton! Will check those threads, try just updating the firmware, then will try the sample code if that doesn’t work. Will report back once I am able to do that and can test the modules again.