2) Open HyperTerminal from -> All Programs -> Accessories -> Communications -> HyperTerminal. 3) Enter a name for the connection and press OK. 4) Now select the communication port (COM) at GSM module is connected. 5) Create a new connection set on HyperTerminal. Set parameters, like baud rate as 9600, handshaking mode as none, parity bit as none, stop bit as 1 and data bit as 8. 3.1.7 MAX 232: Max232 IC is a specialized circuit which makes standard voltages as required by RS232 standards. This IC provides best noise rejection and very reliable against discharges and short circuits. MAX232 IC chips are commonly referred to as line drivers. To ensure data transfer between PC and microcontroller, the baud rate and voltage levels of Microcontroller and PC should be the same. The voltage levels of microcontroller are logic1 and logic 0 i.e., logic 1 is +5V and logic 0 is 0V. But for PC, RS232 voltage levels are considered and they are: logic 1 is taken as -3V to -25V and logic 0 as +3V to +25V. So, in order to equal these voltage levels, MAX232 IC is used. Thus this IC converts RS232 voltage levels to microcontroller voltage levels and vice versa. 3.1.7.1 Pin Configuration: Fig 3.9: Pin diagram of MAX 232 IC 3.1.8 RS 232(Female Port) RS-232 is the component which is used to connect system (pc) to microcontroller. RS-232 (Recommended Standard 232) is the traditional name for a series of standards for serial binary data and control signals connecting between a (Data DTE
2) Open HyperTerminal from -> All Programs -> Accessories -> Communications -> HyperTerminal. 3) Enter a name for the connection and press OK. 4) Now select the communication port (COM) at GSM module is connected. 5) Create a new connection set on HyperTerminal. Set parameters, like baud rate as 9600, handshaking mode as none, parity bit as none, stop bit as 1 and data bit as 8. 3.1.7 MAX 232: Max232 IC is a specialized circuit which makes standard voltages as required by RS232 standards. This IC provides best noise rejection and very reliable against discharges and short circuits. MAX232 IC chips are commonly referred to as line drivers. To ensure data transfer between PC and microcontroller, the baud rate and voltage levels of Microcontroller and PC should be the same. The voltage levels of microcontroller are logic1 and logic 0 i.e., logic 1 is +5V and logic 0 is 0V. But for PC, RS232 voltage levels are considered and they are: logic 1 is taken as -3V to -25V and logic 0 as +3V to +25V. So, in order to equal these voltage levels, MAX232 IC is used. Thus this IC converts RS232 voltage levels to microcontroller voltage levels and vice versa. 3.1.7.1 Pin Configuration: Fig 3.9: Pin diagram of MAX 232 IC 3.1.8 RS 232(Female Port) RS-232 is the component which is used to connect system (pc) to microcontroller. RS-232 (Recommended Standard 232) is the traditional name for a series of standards for serial binary data and control signals connecting between a DTE (Data
114268331-SMS-based-Notice-board.docx