sim900

[Sandip]

I have purchased new gsm900 and working on sending sms using Atmega16a . Problem is I think it not responsing on AT command

I follow your code for satisfaction then also it is  not responding.The module is a new one.I am also new in this field .hope you will help me. 

                                                                                                 

                                   Thank you,

[AJISH ALFRED]

Hi Sandip,

What normally happens is that some module have max232 ic built in it and some don’t. If there is any then you have to add one in your circuit. Please check this and check if there is any other mistakes in the hardware. The code posted in this website are all working and you can find a working video also.

[Sandip]

Thank you for your attention,I have tried all my best but it’s not working.

Will you help regarding how to interface max232.

Else if i use usb to ttl then will it work proper.

 

[AJISH ALFRED]

 

I wonder where will you connect the usb side of the usb to ttl converter to a microcontroller ! Ofcourse you can check it with a PC. 

First confirm whether your sim900 module has a max232 built in or not. If not you have to add one externally. Learn this project, the circuit diagram will be useful for you.

 

http://www.engineersgarage.com/microcontroller/8051projects/interfacing-gsm-8051-microcontroller-circuit-code

[Author]

Posts