SIM900 GPRS HTTP AT Commands
Before you begin make sure your SIM900 GSM module has acquired the network and it is ringing when you make a call to it. Then test the basic AT commands and then proceed further.
Once you are ready, you can start by first setting up the GPRS connection as follows,
Text in RED is typed by me and text in GREEN is the response from SIM900 module.
Setting up GPRS connection
Set the connection type to GPRS
AT+SAPBR=3,1,”Contype”,”GPRS”
OK
Set the APN to to “www” since i am using a Vodafone SIM card, It might be different for you, and depends on the network
AT+SAPBR=3,1,”APN”,”www”
OK
Enable the GPRS
AT+SAPBR =1,1
OK
Query if the connection is setup properly, if we get back a IP address then we can proceed
AT+SAPBR=2,1
+SAPBR: 1,1,”100.120.204.132″
OK
Getting the contents of a webpage from the server
We will get the content of the webpage from my old website at the url http://marsinnovations.in/testout.php, which is a simple web page that puts out some dummy text as shown below. You can retrieve any webpage you want.
We were allocated a IP address and now we can proceed by enabling the HTTP mode
AT+HTTPINIT
OK
OPTIONAL, ONLY IF URL is HTTPS or SSL enabled: Also Remove the http:// part in the HTTPPARA=”URL”,xxxx command
AT+HTTPSSL=1
OK
Start by setting up the HTTP bearer profile identifier
AT+HTTPPARA=”CID”,1
OK
Set the url to the address of the webpage you want to access
AT+HTTPPARA=“URL”,”http://marsinnovations.in/testout.php”
OK
Start the HTTP GET session, by giving this command
AT+HTTPACTION=0
OK
The below output from module indicates it has read 654 bytes of data and the response of the HTTP GET request is 200, which means success
+HTTPACTION:0,200,654
The below command tells the module that we want to read the received data
AT+HTTPREAD
The below is the data read from the webpage
+HTTPREAD:654
Logged Meter Readings:<br>Date Time: Current Voltage Temp.<br>
<br>Mon May 19 23:56:12 2014 :485683465429634
<br> :485683465429634
<br>Tue May 20 00:00:13 2014 :948598437599980
<br>Tue May 20 00:04:41 2014 :948598437599980
<br>Tue May 20 00:24:39 2014 :9485
<br>Tue May 20 00:25:37 2014 :9485
<br>Tue May 20 00:40:50 2014 :23423
<br>Wed May 21 00:07:19 2014 :948598437599980
<br>Wed May 21 00:43:20 2014 :34234324
<br>Wed May 21 00:47:15 2014 :34234324
<br>Wed May 21 11:12:10 2014 :34234324
<br>Wed May 21 15:23:22 2014 :34234324
<br>Wed May 21 15:28:07 2014 :564575676
<br>Wed May 21 15:38:06 2014 :564575676
<br>Wed May 21 15:43:53 2014 :564575676<br>
OK
The contents above are the contents of the webpage shown before.