Posting to php server using SIM900 GPRS with AT commands
General Tech Bugs & Fixes 2 years ago
Posted on 16 Aug 2022, this text provides information on Bugs & Fixes related to General Tech. Please note that while accuracy is prioritized, the data presented might not be entirely correct or up-to-date. This information is offered for general knowledge and informational purposes only, and should not be considered as a substitute for professional advice.
Answers (2)
manpreet 2 years ago
After much googling and mashing together various answers, I got it working.
Here's the AT command sequence. You can test this from start to finish, you'll just need to confirm the APN of the carrier you're using.
// My comments are here Command to send is here Expected responses are here // See if the SIM900 is ready AT OK // SIM card inserted and unlocked? AT+CPIN? +CPIN: READY OK // Is the SIM card registered? AT+CREG? +CREG: 0,1 OK // Is GPRS attached? AT+CGATT? +CGATT: 1 OK // Check signal strength - should be 9 or higher AT+CSQ +CSQ: 14,0 OK // Set connection type to GPRS AT+SAPBR=3,1,"Contype","GPRS" OK // Set the APN - this will depend on your network/service provider AT+SAPBR=3,1,"APN","wholesale" OK // Enable GPRS - this will take a moment or two AT+SAPBR=1,1 OK // Check to see if connection is correct and get your IP address // (I hid mine here, but you'll get a real IP back) AT+SAPBR=2,1 +SAPBR: 1,3,"0.0.0.0" OK // Enable HTTP mode AT+HTTPINIT OK // Set HTTP profile identifier AT+HTTPPARA="CID",1 OK // Put in the URL of the PHP webpage where you will post - // the URL below is a test server so you can use it in testing AT+HTTPPARA="URL","http://posttestserver.com/post.php" OK // Tell the SIM900 how much data you'll send (18 bytes here) // and how long to wait for a time-out (10,000 ms here) AT+HTTPDATA=18,10000 DOWNLOAD // Key in the data you want to send after you get the "DOWNLOAD" prompt. vdc=12&adc=3&rel=8 OK // Post the data - wait a second for the response AT+HTTPACTION=1 OK +HTTPACTION:1,200,142 // Read the response - www.posttestserver.com will give you a // URL where you can confirm that it's working AT+HTTPREAD +HTTPREAD:142 "Successfully dumped 0 post variables. View it at http://www.posttestserver.com/data/2016/04/28/14.19.041655610622 Post body was 18 chars long." OK // Close the HTTP connection AT+HTTPTERM OK // Disconnect the GPRS AT+SAPBR=0,1 OK
Edit to add: Here are the sources I used to put all of this together, along with help from some folks I asked in my lab.
No matter what stage you're at in your education or career, TuteeHub will help you reach the next level that you're aiming for. Simply,Choose a subject/topic and get started in self-paced practice sessions to improve your knowledge and scores.
Which operating system you favour and why?
General Tech 10 Answers
What are the most popular tech portals in India?
General Tech 7 Answers
What are best technologies available today for education / aiding learning?
General Tech 3 Answers
What professional training certifications are most marketable?
General Tech 9 Answers
manpreet![Tuteehub forum best answer]()
Best Answer
2 years ago
I am using a SIMCOM SIM900 GSM/GPRS module in an embedded hardware application. Rather than sending device data to a server by SMS (what I've been doing so far) I want to switch and start using GPRS to post data to a server with a PHP script I've written.
The SIM900 literature (pdf) is abysmal. Section 13 gives an example sequence for connecting GPRS, which I've pieced together with a few other bits, but I can't get it working:
*COMMAND* *RESPONSE* *COMMENT* ATD*99# CONNECT Establish connection AT+CGATT? +CGATT:1 Check connection AT+CGDCONT=1,"IP" OK Set context AT+HTTPINIT OK Enable HTTP mode AT+HTTPPARA="URL","www.google.com" OK Set the address AT+HTTPDATA="data" OK Send some dataI am getting the expected responses, but nothing happens after the last step.