Reading SMS from SIM808 GSM/GPRS/GPS Modem with ATmega32
In this project, we will learn Reading SMS from SIM808 GSM/GPRS/GPS Modem with AVR ATmega32 Microcontroller. Here, we will read a text message(SMS) from the SIM808 GSM/GPRS/GPS modem memory with ATmega32 microcontroller and we will display the content of the SMS in a 16X2 alphanumeric LCD.
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 "AT+CMGR" AT command( AT+CMGR command is used to read a SMS) with the memory location 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 SMS reading in the alphanumeric LCD. The alphanumeric LCD will display "Empty Location" if the memory location is empty or it will display "Error" if AT command is not executed properly or it will display the content of the SMS. The 16X2 alphanumeric LCD will display 1st 32 characters of the SMS only as the LCD can display only 32 characters at a time.
Now, read any SMS stored in the SIM808 GSM/GPRS/GPS modem and display it in the 16X2 alphanumeric LCD.