AT Commands are Instructions and used for control a Modem. Every Command line start with "AT". That's why modem commands are called AT commands.
Setup testing procedure for AT commands:
This article describes the AT commands for reading, sending and deleting SMS and also receiving, dialing, hanging a CALL from the SIM300 GSM modem inbox. You can also check the balance in sim card in SIM300.
- Insert the SIMCARD into SIM Tray
- Connect the RS232 cable to the PC serial port (DB-9)
- Open hyper terminal from windows
- Select the COM port with baud rate 9600
- Type AT commands and press enter and you will get OK; that means communication is OK.
Reading a SMS from the Inbox:
AT+CMGF=1 then Press Enter
AT+CMGR= no. and press enter; Number (no.) is the message index number stored in the SIM card.
The modem will reply with the text of the first SMS in the inbox along with sender’s mobile number, date and time.
Sending SMS from SIM300:
AT+CMGF=1 press enter
AT+CMGS=”mobile number” press enter
Once The AT commands is given’ >’ prompt will be displayed on the screen.
Type the message to send via SMS. After this, press ctrl+Z to send the SMS.
If the SMS sending is successful, “ok” will be displayed along with the message number.
Deleting a SMS from inbox:
Receiving an incoming Call:
To receive a ringing call, type the command ATA and press enter
Dialing a new number from SIM300:
To call to a number send the command ATD followed by the mobile number
For example, to call the mobile number 9928142466 send the command as, ATD9928142466; and press enter
Hanging up a call:
To hang up a ringing call or a call in progress type the command ATH and press enter
AT+CMGF=1 then Press Enter
AT+CMGR= no. and press enter; Number (no.) is the message index number stored in the SIM card.
The modem will reply with the text of the first SMS in the inbox along with sender’s mobile number, date and time.
Sending SMS from SIM300:
AT+CMGF=1 press enter
AT+CMGS=”mobile number” press enter
Once The AT commands is given’ >’ prompt will be displayed on the screen.
Type the message to send via SMS. After this, press ctrl+Z to send the SMS.
If the SMS sending is successful, “ok” will be displayed along with the message number.
Deleting a SMS from inbox:
- To delete the first message from the inbox type the command AT+CMGD=1 and press enter; the modem will delete the first message in the inbox.
- To delete the second message from the inbox type the command AT+CMGD=2 and press enter; the modem will delete the second message in the inbox …..and so on.
Receiving an incoming Call:
To receive a ringing call, type the command ATA and press enter
Dialing a new number from SIM300:
To call to a number send the command ATD followed by the mobile number
For example, to call the mobile number 9928142466 send the command as, ATD9928142466; and press enter
Hanging up a call:
To hang up a ringing call or a call in progress type the command ATH and press enter
How to check a balance in SIM300?
To check a balance in your simcard in SIM300 type the command ATD followed by your service provider balance checking number; For example to check balance for Airtel or BSNL; type ATD*123# and press enter, You will get your simcard balance with expire date.
