detect if anyone use GSM jammer…

20 thoughts on “detect if anyone use GSM jammer…

  1. Hi.

    question for expert . I use GE865 quad and want make solution how to detect if anyone use gsm jammer signal. Is there anyway to detect it???



      1. Yes, see Jammed Detect & Report AT Commands ie AT#JDR. 

        OK. I find on document this : AT#JDR=6

        if use this command then gsm module result :


        1.  #JDR: JAMMED is if detect Jammed

        2.  #JDR: OPERATIVE is normall operation no jammed detect

        3. #JDR: UNKNOWN is default state before 1st PLMN searching – what is it  PLMN acronym


        but I thinks so   #JDR: UNKNOWN is if don’t find operator and still search



          1. Hi again I have some problem with #JDR

            I test this AT#JDR=6 but result is error .  

            my software revision is 10.00.002

            if test this command AT#JDR=4 then I must receive every 3sek information about JDR but not respond.


            what is wrong?? 

          2. What error (set AT+CMEE=2)?

            With mode 4 the URC appears in jamming conditions only – do you use a jammer to test?


  2. if test :

    +CME ERROR: operation not supported

    I don’t have jammer,

    OK I can use AT#JDR=4 command .

    but if use AT#JDR=1 is possible to read state pin with #GPIO ???

    or first I must define alternate pin function. 

    I don’t have connect any pin from my MCU  in to GPIO2 (JDR alternate pin function).


    if jammer change state on GPIO2 pin is possible to read this state with at command??


    I test this :


    and return this:

    #GPIO: 1,0

    it’s mean so this GPIO is output and is log 0.

    if  jammer detect change this GPIO to 1 then I receive this ???

     #GPIO: 1,1 or doesn’t matter what is jammer state still receive #GPIO: 1,0




      1. how  I enable alternate GPIO function???

        on data sheet is write so GPIO2 can be input,output or alternate JDR function.

        How can I define alternate GPIO2 JDR .


        I try only set, clear pin state on this  GPIO and work but how to define JDR.

        check state I use AT#GPIIO=2,2



          1. if JDR set alternate function then if define this pin to output and set 0 or 1 then 

            it’s only virtual change pin state???

            on GE865 is GPIO2 near the GPIO1 , but need I connect any Pull up or pull down resistor to good work??


          2. No need to do anything else! The pin changes to reflect jammed state.

            Simply connect the GPIOs, set GPIO to input and read it.

  3. Really Smile You can however insert a resistor of some KOhms between pins to deal with eventual signal contention, both GPIO set to output.


    But I still cannot understand what would you do this instead reading with AT#JDR. The output on GPIO is meant to be used for "alarming" an external device. 

      1. I’m again test #JDR command .

        on page 559 of AT command reference guide  and there is used command :


        #JDR: OPERATIVE //when in normal operating mode

        but I receive error. 


        6 – enables the Jammed Detect (this value is available only for release); the Jammed condition is reported in the format:
        #JDR: <status>
        JAMMED – Jammed condition detected
        OPERATIVE – Normal Operating condition restored. This code will be shown only after a jammed condition has occurred
        UNKNOWN – default state before first successful PLMN searching


        +GMR return firmware version. I have this release or not??? 


        1. I would not doubt, if the answer is that. There is a newer version for your module, 10.00.003, and #JDR was updated too.