How to send AT commands to SIM900 with Arduino

Projects Networking, Protocols, and Devices
1

Hi everyone,

I got a SIM900 shield (http://www.ebay.com/itm/SIM900-Quad-band-GSM-GPRS-Shield-for-Arduino-UNO-MEGA-Leonardo-/321418410538?hash=item4ad607ba2a:g:YikAAOxyRNJSjs3T). I've been trying the past few days to send an sms but I couldn't. The green light blinks every 3 seconds which means that the shield is registered to a network. I upload the code to send an sms (no errors) and nothing happens. I have this library: GitHub - MarcoMartines/GSM-GPRS-GPS-Shield: GSM/GPRS & GPS Shield Library for modules using SIM900/SIM908 . I would like to know if there is something wrong with the code or the shield. That's why I want to do it manually (test connection etc.). Could you please tell me how can I send AT commands to SIM900 through the serial monitor of the Arduino IDE? I am using an Arduino uno. I have already tried tons of code to send an SMS but nothing seemed to work.

Thanks in advance.

2

I got a SIM900 shield

for which you posted a useless link. There are NO details about that shield. ALL that ebay cares about is separating you from your money.

If you expect help, post a link to the manufacturer's site, NOT some useless picture site.

I upload the code to send an sms (no errors)

What code would that be?

I would like to know if there is something wrong with the code or the shield.

Probably not. Or maybe. No one here knows because you have not provided enough information.

3

ludr122:
I would like to know if there is something wrong with the code or the shield.

Probably neither. I bet you aren't getting a satellite fix. Without that, you have 0 GPS data.