RFM95 Frequency 868 vs 915 Mhz

[snatch]

I’ve ordered RFM95 868Mhz module from Ali (The module is marked on the backside with 868).
It is connected to ESP32-C3.
I’m using LMIC lib from mcci-catena/MCCI LoRaWAN LMIC library@^5.0.1

The problem is that it uses frequency 915Mhz.

I print in the loop function once:

Serial.print("Status: ");
Serial.println(LMIC.opmode); 

Serial.print("Data Rate: ");
Serial.println(LMIC.datarate);

Serial.print("Tx Power: ");
Serial.println(LMIC.txpow);

Serial.print("Frequency: ");
Serial.println(LMIC.freq); 

and it outputs (with: LMIC_DEBUG_LEVEL=1)

RXMODE_RSSI
631515: engineUpdate, opmode=0x8
Packet queued
631803: EV_JOINING
631808: engineUpdate, opmode=0xc
631838: EV_TXSTART
631912: TXMODE, freq=912100000, len=23, SF=10, BW=125, CR=4/5, IH=0
Status: 2188
Data Rate: 0
Tx Power: 30
Frequency: 912100000
start single rx: now-rxtime: 4
967476: RXMODE_SINGLE, freq=923900000, SF=10, BW=500, CR=4/5, IH=0
rxtimeout: entry: 968371 rxtime: 967464 entry-rxtime: 907 now-entry: 5 rxtime-txend: 312375
start single rx: now-rxtime: 4
1029974: RXMODE_SINGLE, freq=923300000, SF=12, BW=500, CR=4/5, IH=0
rxtimeout: entry: 1033559 rxtime: 1029964 entry-rxtime: 3595 now-entry: 4 rxtime-txend: 374875
1033590: Unknown event: 20
1033599: engineUpdate, opmode=0xc
1075480: engineUpdate, opmode=0xc
1075506: EV_TXSTART
1075581: TXMODE, freq=912600000, len=23, SF=8, BW=500, CR=4/5, IH=0
start single rx: now-rxtime: 4

I tried some buildflags in platformio, but
-DLORA_FREQUENCY=868100000

and also some defines
#define CFG_eu868 1
#define CFG_sx1276_radio 1
#define LMIC_DEBUG_LEVEL 2
#define LMIC_FAILURE_TO Serial
#define DISABLE_PING
#define DISABLE_BEACONS

But the output eg. freq not at 868Mhz.

Any clues?

[Jeff-UK]

The RFM will only output (or try to output) what it is programmed to do via the external MCU - the RFM is basically a RF tranceiver only sub-system, not a full RF Modem. Look to your LMIC code/config. Clearly it ‘thinks’ (based on the debug output) it is on the higher band: there is something left in the code actually configuring to 915 band - have you set all parameters correctly to use 868?. Also how have you configured in TTN Console - have you accidently set that as 915 vs registering as 868? ABP or OTAA? How are Console frequencies configured?

What do you see in your GW traffic? (Do you have your own GW?)

You likely need to comment out overiding 915/923 settings? (note also the repeating BW=500!). Also for e.g. US915 anything beyond SF10 basically unusable (Dwell time limits!) so seeing SF12 is annomolous…)

[snatch]

I found the issue with wrong band after further reading the documentation - as usual
After adding the following additional buildsflags:
-D ARDUINO_LMIC_PROJECT_CONFIG_H_SUPPRESS
-D CFG_eu868=1
-D CFG_sx1276_radio=1

It keep going the right way:

Thank you for your thoughts, Jeff