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

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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: https://meshtastic.discourse.group/t/rak4631-rak19007-rf-switch-problem/

(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_SPREADING_FACTOR LORA_SF12 // [SF7..SF12]
#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