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. I am experiencing an identical issue with the GE865-QUAD on the EVK2 and our hardware using 10.00.005 firmware.

      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