IF ANY COMMAND BELOW DOES NOT WORK CORRECTLY ADD A Semicolon ‘ ; ‘
In order to establish the PPP connection:
- AT+CGDCONT? This should respond with the context you are on. This means you are ready to attach/connect.
- AT+CGATT=1 (attach your modem)
- AT+CGDATA=? (check what is the data mode)
- AT+CGACT=1 (activate your connection)
Now you are on PPP, and then you talk over the modem using whatever your provider is using. It could be anything from direct HTTP to MMSE protocol.
For example, here is a complete transcript over HTTP. First, we need to setup the modem and connection information. All these commands should get a response of OK from the modem.
AT+CMMSINIT # Initialize the MMS method
AT+CMMSCURL=”some.url.com” # the MMS center URL
AT+CMMSCID=1 # Set bearer
AT+CMMSPROTO=”1.1.1.1″,8080 # MMS Proxy information
AT+SAPBR=3,1,”Contype”,”GPRS” # How you are sending
AT+SAPBR=3,1,”APN”,”foobar” # Set the APN
AT+SAPBR=1,1 # Activate the bearer context
Next, we prepare the message:
> AT+CMMSEDIT=1 # Enter edit mode
OK
> AT+CMMSDOWN=”PIC”,54321,30000 # Download a pic that is 54321 bytes
# and set the latency
# for the download to 30000 ms
CONNECT # This means, ready to receive data
# so send your file
OK # Data received
> AT+CMMSRECP=”123456789″ # Set the recipient
OK
> AT+CMMSVIEW # View your message
(your message)
OK
> AT+CMMSSEND # Send the message
OK # Message sent
> AT+CMMSEDIT=0 # Exit edit mode, and clear the buffer
OK
IN OUR CASE USE :
Some.url.com = http://smpl.mms.msg.eng.t-mobile.com/mms/wapenc
foobar = simple
http://www.jarzebski.pl/datasheets/SIM900_mms-121012-1.02.pdf
MMS Proxy: 216.155.165.50:8080
TCP Connection over GPRS using SIM900 and AT Commands
a couple questions…
MMS PROXY… what is it ? how do you obtain the IP address and port number for it ???
also, “PIC”, is that the file name of the image file ???
I found my MMS Proxy on a list of MMS details on google, but I can’t find the page now. PIC is the kind of file you are sending, it can also be set to TXT and other things, please see the PDF that I referenced at the bottom of the article.
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