Dialing a Number from SIM808 GSM/GPRS/GPS Modem with ATmega32
In this project, we will learn how to Dialing a Number from SIM808 GSM/GPRS/GPS Modem with AVR ATmega32 Microcontroller. Here, we will dial to a mobile number from the SIM808 GSM/GPRS/GPS modem with ATmega32 microcontroller and we will display the status of the call or anyother event(like new call, new SMS) that may occur during the call in a 16X2 alphanumeric LCD. If the call gets connected to the dailed number, then we will talk with person on other side with a headphone.
When the SIM808 GSM/GPRS/GPS modem power is turned on, the ATmega32 microcontroller reads the initial status data sent by the SIM808 GSM/GPRS/GPS modem through USART protocol. After reading the status data, the ATmega32 microcontroller processes the SIM808 GSM/GPRS/GPS modem status data and displays the status of the modem and SIM in the alphanumeric LCD. If SIM card is not present, then "Plz Insert SIM" is displayed, if SIM card is present and modem is ready, then "SIM900 is Ready" is displayed and for other conditions, "SIM900 Error" is displayed in the alphanumeric LCD.
Now, when the SIM808 GSM/GPRS/GPS modem is ready, the ATmega32 microcontroller will send the "ATD" AT command( ATD command is used to dial a number) with the mobile number to which we want to call to the SIM808 GSM/GPRS/GPS modem. In response to the AT command, the SIM808 GSM/GPRS/GPS modem will a send a response to the ATmega32 microcontroller. The ATmega32 microcontroller will analyse the response and accordingly it will display the status of number dailing in the alphanumeric LCD. The alphanumeric LCD will display "Dailing..." in its 1st row and the dailed mobile number in the 2nd row if SIM808 GSM/GPRS/GPS modem dials to the mobile number or it will display "No Dial Tone" if there is no network or it will display "Error" if AT command is not executed properly or "Other Error" for other types of error in the SIM808 GSM/GPRS/GPS modem. And if during the dailing process or during the call if any types of events(like New SMS, Incoming Call, Number Busy, No Answer or others) occurs, then that event will be displayed in the 16X2 alphanumeric LCD. Now, if the call gets connected with the dailed number, then we will talk with the person on the other side by connection a 3.5mm headphone with the SIM808 GSM/GPRS/GPS modem.
Now, make your 1st call from the SIM808 GSM/GPRS/GPS modem and talk to anyone from your new mobile phone.