LOW Rssi value even though the TX is 10 cm close to the RX

[gc9n]

i am experiencing some low RSSI values when the incoming package arrives i read the RSSI Value , and the higest i get is -80 , on the SDRi can see -20 the TX signal is super strong .

i am using LORA not GFSK for this task . and i am wondering if the RX part is correct

`void loadCandidate(float freq) {
 radio.standby();
 if (radio.setFrequency(freq, true) == RADIOLIB_ERR_NONE) {
   radio.setRxBoostedGainMode(true);

   radio.startReceive();
   LORA_candidateStartTime = millis();
   DPRINTLN("  ");
   DPRINT("Frequency set to: ");
   DPRINT(gCurrentFrequency);
   DPRINTLN(" MHz");
   DPRINTLN("  ");
 }
 else
 {
       DPRINT("ERROR SETTING FREQ!!!!!!!!!!!! ");

 }
}`

[jgromes]

Which module are you usign, what is the RSSI value that you expect and can you verify it with an independent setup? I'm asking because it is of course possible the RSSI calculation is wrong, but I think it is rather unlikely.

[gc9n]

i am sorry for miss information , I am using the LR1121 i made some more tests and i realeased that , getting a GFSK is less sensitive than LORA ,
however ALso Lora RSSI is not what i expect to get , becasue TX and LR1121 is next to each other

on GFSK i tried to use average to get the RSSI with inst howver i got more or less the same results

    float rssiSum = 0;
    int sampleCount = 0;
    while (millis() - startTime < 15) {
      float rssiTemp;
      state = radio.getRssiInst(&rssiTemp);
      rssiSum += rssiTemp;
      sampleCount++;
      delayMicroseconds(2);
    }
    float avgRssi = (sampleCount > 0) ? (rssiSum / sampleCount) : 0;

[gc9n]

UPDATE
getting the rssiSync value is giving me much better results why? not perfect but better from -120 i am at least -88 now
radio.getPacketStatusGFSK(&rssiTemp,NULL,NULL,NULL);

[gc9n]

i am using this method to get it

float rssiSum = 0;
    unsigned long startTime = millis();
    int sampleCount = 0;
    while (millis() - startTime < 10) {
      float rssiTemp;
      radio.getPacketStatusGFSK(&rssiTemp,NULL,NULL,NULL);
      rssiSum += rssiTemp;
      sampleCount++;
      delayMicroseconds(1);
    }
    float avgRssi = (sampleCount > 0) ? (rssiSum / sampleCount) : 0;

[HeadBoffin]

A classic LoRaWAN chestnut - Long Range - for devices that can do km, 10cm is shouting very very loudly in the receivers ear causing all sorts of potential issues with signal distortion. Or just really really bad antennas.

Getting some dev boards about 10m apart with a brick wall between to set a standard for your environment. Use the antenna's that come with the kit - YMMV as to their performance, but it gives you a something you can run side by side.

Note: You re-iterated which chips you are using, but didn't say which modules - are they hand built or from a vendor?

[gc9n]

sorry for my ignorance what exactly does the setRssiCalibration ? and how we use it?