I recently bought a 'TinySine 3G shield (SIM5320E) 900/2100Mhz' based on Adafruit_FONA libraries to use with Arduino Mega 2560 R3. It successfully registered with Vodafone AU. Other functionality works (SMS, GPS) but not HTTP/TCP.

View from SimCom AT Command Tester

I'm following this TCP/UDP section of SimCom tutorial to receive data from a REST API. But I cannot set the APN for TCP as there is no support for AT+CSTT command as it seems.

I can see it's on WCDMA network.


    +CPSI: WCDMA,Online,505-03,0x014E,xxxxxxx,WCDMA IMT xxxx,xxx,xxxx,0,12.0,97,12,18,500

Error comes here


Is there a way to resolve this issue - With the same setup/libraries OR - By upgrading libraries/firmware of the module OR - Using any other set of commands

Please provide if any of you have a sample code to access a REST API. Appreciate your help very much.

  • did you follow the HTTP section of that tutorial? .... it uses commands that you did not mention in your post
    – jsotola
    Sep 1 '18 at 17:20
  • Thanks for the comment. I corrected the link. I followed the TCP/UDP section to be exact.
    – SajithP
    Sep 3 '18 at 0:42

CSTT works on GPRS modules like SIM900. I found a way to get SIM5320E working to download websites. Tested with TeraTerm and used <Ctrl M> and <Ctrl J> instead of '<CR> <LF> OR /r/n' characters.

Network setup

AT+CGDCONT=1,"IP","<your APN>",""

Start HTTP service You can stop and start service if it's not responding properly.


HTTP GET request

GET /test.php HTTP/1.1  <-- don't hit enter, instead hit the below 2 keys
<Ctrl M>
<Ctrl J>
Host: www.iforce2d.net  <-- don't hit enter, instead hit the below 2 keys
<Ctrl M>
<Ctrl J>
Connection: close  <-- don't hit enter, instead hit the below 4 keys. This is useful when connecting to REST APIs to download the the respective result only.
<Ctrl M>
<Ctrl J>
<Ctrl M>
<Ctrl J>

To end the command and to receive results:

<Ctrl Z>

You will receive a lot of data here.

Stop HTTP service


You will get the contents of the website. Probably it should contain the data you need (I didn't test the content. May be you will need to tweek the result a bit.)

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