DTMF decode -> No carrrier

4 thoughts on “DTMF decode -> No carrrier

  1. I am using the GC864-QUAD-V2 unit for decode DTMF tones. (Firmware 10.00.055)
    I got a strange behavior together with the EVK2 Board.

     

    sequence:

    AT#QSS=1
    AT+CPUMODE=1
    AT+DTMF=1

    RING,RING, RING

    ATA

    sometimes after ATA or after a few received #DTMFEV: …. I get a indication:

    NO CARRIER    #QSS: 0

    I checked the failure with the AT#CEER command
    #CEER: 255    (lower layer failure)

    I checked also AT+CPIN?
    +CME ERROR: SIM failure

    So, I used already 2 SIM cards from different provider and I am sure, there is no contact problem with the SIM card holder (#QSS: 0).

    I have already an idea:

    Is it possible that the command  AT+CPUMODE=1 need to much current from the internal power supply of the EVK2 Board?

      1. Hi,

        both #QSS=0 and +CME ERROR: SIM failure ,make me to suppose there is a false contact or something else
        that harm the SIM connection. CPUMODE don’t increase a lot the average current consumption and anyway
        EVK2 has been designed with a power supply in order to guarantee the need current, if external power supply can
        do it of course.
        What about a call with #DTMF=0 ? still same problem?

        1. Hi,

           

          You are right, there is no issue with the power supply. 

          There is only a bad behavior if the sequence is:

           

          RING

          AT+CPUMODE=1

          AT+DTMF=1

          RING