Detection of dropped voice calls

2 thoughts on “Detection of dropped voice calls

  1. I need to be able to distinguish a remote hangup from a dropped call.

    I don’t have a convenient way of simulating a dropped call so I can’t experiment much.


    I turned on



    so when the remote hangs up I get the unsolicited result code:



    Is there a different unsolicited result code if the call is dropped due to losing the signal?

    Is there a command that will allow the software to tell why a call was terminated. It appears that maybe


    might give the answer but the documentation does not state what the return report would be for a dropped call.





    1. AT#CEER has a list of error codes in its description in AT Commands Reference Guide.


      Remote refusing the call (hang-up): DIALING/RINGING/BUSY; code 17 User busy.


      Detaching the antenna during call: DIALING/RINGING/CONNECTED/DISCONNECTED; NO CARRIER and code 255 Lower layer failure.