Sim900 dtmf USING AT+DDET COMMAND

[nngohel]

Hi

i use sim900 and firmware
1137b08sim900m64_st_dtmf_jd_mms

i also use mic for ivrs
when there is no voice transfer form modem to mobile.....dtmf are working
but when there is a voice transfer from modem to mobile.....dtmf are not working properly ,some time randomly dtmf are skip...

For example
------------------------------
no voice from modem to mobile
send dtmf 12345
in hyper-terminal
+dtmf:1
+dtmf:2
+dtmf:3
+dtmf:4
+dtmf:5
------------------------------
voice from modem to mobile
send dtmf 12345
in hyper-terminal
+dtmf:1
+dtmf:3
+dtmf:5
------------------------------

any one help me !!!!

 

[binjet7]

Hi nngohel,
Can you show me: How to SIM900B can detect dtmf from my mobile when i call to SIM900B:

Revision:1137B01SIM900B64_ST_ENHANCE

Send: AT+DDET=1
Return: OK

...Receive an incoming call
Send: ATA
Return: connection is successful

From my button of Mobile: i press "1" or "2"... but i don't see SIM900B reported via serial port
Help me, i must send another AT command?
Thank?

 

[binjet7]

I done it, i must update other version.

 

[Ali_54]

hello, tried to put to module via customer flash loader "1137B03SIM900M64_ST_MMS.cla" and "1137B08SIM900M64_ST_DTMF_JD_MMS.cla"
but both give errors like:
Reception uncomplite
00' 26'' 520 - Err 307 - Error during flash erase
00' 26'' 535 - Err 307 - Error during flash erase

How can I get over this problem?

Notice: I m using sim900 EVB evolution board orginally simcom.

 

[jaruwit]

Hi I try use sim900 to detect DTMF but found error. I use firmware 1137B11SIM900M64_ST. please help.

Data sent: AT+CGMR
Data received: AT+CGMR
Revision:1137B11SIM900M64_ST
OK
Data sent: AT+DDET=1
Data received: AT+DDET=1
ERROR

Data sent: AT+DDET=0

Data received: AT+DDET=0

ERROR