Fona 800H +SJDR: NO JAMMING

hello everyone,

im trying to test the jamming and interference comand

http://cristiansteib.github.io/Sim800l/info/SIM800+Series_AT+Command+Manual_V1.09.pdf

you can see it on page 190.

the comand is AT+SJDR=1,3,50,1
1= enables jamming detection
3= enables the output pin and notification URC via serial
50= treshold between jamming and interference
1= reports only when status changes (i also tried 0 witch reports every 3 secons on serial monitor.

OK
FONA> 
+SJDR: NO JAMMING

+SJDR: NO JAMMING
z
Sendcomannd
AT+SJDR=1,3,50,1

OK
FONA> K
Sendcomannd
AT+SJDR?

+SJDR: 1,1,5,1,0

OK
FONA> K
Sendcomannd
AT+SJDR?

+SJDR: 1,1,5,1,0

OK

i based the code con the fonatest example and added this comand. the serial responds "OK".

i have a jammer here it disables the phones, wifi, bluetooths. but the serial monitor keeps printing "+SJDR: NO JAMMING".

i algo tried to enable the APN with the default and with the one we use here. algo i enabled the GPRS and test it with the gprs location.

here are the commands i send because the serial tube seems to have some issues

      case 'z': {
        Serial.println(F("Sendcomannd"));
        delay(1);
        
        while (1) {//AT+CSCLK=0
          fona.write('A');
          fona.write('T');
          fona.write('+');
          fona.write('S');
          fona.write('J');
          fona.write('D');
          fona.write('R');
          fona.write('=');
          fona.write('1');
          fona.write(',');
          fona.write('1');
          fona.write(',');
          fona.write('5');
          //fona.write('0');
          //fona.write('0');
          fona.write(',');
          fona.write('1');
          fona.write('\r');
          fona.write('\n');
          Serial.write("AT+SJDR=1,3,50,1\r\n");
          delay(1000);
          break;
        }
        break;
      }

      case 'k': {
        Serial.println(F("Sendcomannd"));
        delay(1);
        
        while (1) {//AT+CSCLK=0
          fona.write('A');
          fona.write('T');
          fona.write('+');
          fona.write('S');
          fona.write('J');
          fona.write('D');
          fona.write('R');
          fona.write('=');
          fona.write('1');
          fona.write(',');
          fona.write('1');
          fona.write(',');
          fona.write('5');
          //fona.write('0');
          //fona.write('0');
          fona.write(',');
          fona.write('0');
          fona.write('\r');
          fona.write('\n');
          Serial.write("AT+SJDR=1,3,100,0\r\n");
          delay(1000);
          break;
        }
        break;
      }

      case 'K': {
        Serial.println(F("Sendcomannd"));
        delay(1);
        
        while (1) {//AT+CSCLK=0
          fona.write('A');
          fona.write('T');
          fona.write('+');
          fona.write('S');
          fona.write('J');
          fona.write('D');
          fona.write('R');
          fona.write('?');
          fona.write('\r');
          fona.write('\n');
          Serial.write("AT+SJDR?\r\n");
          delay(1000);
          break;
        }
        break;
      }

when the jammer its active i checked the RSSI and it says 0. i checked the network status and it said "no network (searching)" and i also checl the gprs location with a falied displayed on serial. i wait 3 minutes to see if it has some sort of delay but it always shows the no jamming message

Does anyone have tried this AT comand?