Sim900 At commands send

Projects Programming
1

Hello guys, i cant write the correct code about Receiving At commands via sms.

Can someone help me?

I need to receive sms from my Sim900 with signal check command

2

do you have the SIM900 responding to AT commands
what Arduino board are you using?

3

Arduino Uno with sim900

4

have you managed to get AT commands to work?

I no longer use UNOs for anything that uses serial - I find SoftwareSerial unreliable evey at low baudrates
for the SIM900 I use a Arduino Mega which has hardware serial ports pin 18 (link to pin 8) and pin 19 (link to pin 7)
e.g. using AT commands

AT
OK
AT+CGMI
SIMCOM_Ltd
OK
AT+CGMM
SIMCOM_SIM900
OK
5

AT commands works at serial monitor...
but i cant write the right command to send me the message with the values.
eg AT+CSQ

i need to know via sms the signal check.

Can you understand what i need?

6

check signal level and unread message

AT+CSQ
+CSQ: 10,0
OK

+CMTI: "SM",24

AT+CMGL="REC UNREAD"

+CMGL: 24,"REC UNREAD","O2(uk)","","22/04/04,13:44:11+04"
 call 4444 free.
To stop these offers, call 2220.
7

I can understand your answers.

8

if you wish to read the signal quality and then send an SMS text with the value

  1. send AT+CSQ
  2. read the response, e.g. +CSQ: 10,0
  3. send command AT+CMGS=”+TTTTT” when TTTTT is the phone number
  4. when you receive > send response from 2, e.g. +CSQ: 10,0
  5. send CTRL/Z to close the text