sim900 module problem

[nikator]

hi i use sim900 module. u can see it's Schematic in this:
https://www.open-electronics.org/small-breakout-for-sim900-gsm-module/
but wen i turn on this module it's NETLIGHT be turn and blink but when i call it say " the cell phone is turn off" i want use only sms
can any one help me?:sad:

 

[chandu.kurapati]

Hi nikator,
There is some predefined commands on the data sheet to send and receive the message first work it on it. I'm considered the you'r may be using micro controller enable the clock for it and configure the GPIO pin for the Tx and Rx, by using the UART communication protocol you can send the AT commands to the SIM900 module and then it gives the proper response.

I hope it some what help full for you.

Thanks & Regards,
Chandu.kurapati.

 

[nikator]

HI
I want to connect it to PC . i use MAX232. but i can't see any text in Hyperterminal screen. i thinck my module is'n turn on because when i call to it oprator say "your set is turn off"
when i turn module my sim VDD voltage is 1.83vView attachment sim900A核心板.pdf
i can connect module to pc but can not send sms. i rescive this mesege
i thinck it can not finde net. what is the problem?
since i connect anten

 

[chandu.kurapati]

Hi nikator,
I was worked on this command set on hyperterminal, i'm familiar with the software i don't know that much of hardware.

please observe this,

AT\r\n
Response:OK

AT + CMGF = 1\r\n
Response:OK

AT+CMGS = "SIM NUM"\r
Resopne:>write message <CTRL+Z>
AT+CMGS:MSG NUMBER

This is the process i was followed for my project, it's worked fine for me.my advice is first check the voltages of the Tx & Rx pins of the modem and check that other pins also,observe the commands once again.

Thanks & Regards,
Chandu.Kurapati.

 

[joel george]

hiiii
1)it myt not be showing any respoinse on the hyperterminal because u hv turned off few settings in hyperterminal...line echo linefeed carriage return...tick on dem..
2)may be the sim holder is loose because of which there is no network and thus the blue led is not turned ON