Max 232 Communication Implementation using 89C51 Microcontroller
Title of the project: Max 232 Communication Implementation using 89C51 Microcontroller
Domain: Embedded Systems Design
Software: Embedded C, Keil, Proload
Microcontroller: AT89C51
Power Supply: +5V, 500mA Regulated Power Supply
Display: a) LCD
b) LED
LCD: HD44780 16-character, 2-line (16X2)
LED: 5mm White-in-Red, 5mm White-in-Bslue
Crystal: 11.0592MHz
ADC: ADC0804
Key Pad: 3X4
Load Driver: ULN 2803
ABSTRACT
One of the 8051s many powerful features is its integrated UART, otherwise known as a serial port. The fact that the 8051 has an integrated serial port means that you may very easily read and write values to the serial port. If it were not for the integrated serial port, writing a byte to a serial line would be a rather tedious process requiring turning on and off one of the I/O lines in rapid succession to properly "clock out" each individual bit, including start bits, stop bits, and parity bits.
However, we do not have to do this. Instead, we simply need to configure the serial ports operation mode and baud rate. Once configured, all we have to do is write to an SFR to write a value to the serial port or read the same SFR to read a value from the serial port. The 8051 will automatically let us know when it has finished sending the character we wrote and will also let us know whenever it has received a byte so that we can process it. We do not have to worry about transmission at the bit level--which saves us quite a bit of coding and processing time.
In this project, a 3X4 key pad is interfaced to the microcontroller. This project is also provided with a 16X2 LCD and push-to-on switches. In transmit mode if any key on key pad is pressed, the corresponding data will be displayed on LCD and on PC’s hyper terminal window. In Reception mode, any message is typed on key board, the data will be displayed on PC’s hyper terminal window and on the LCD.
The additional feature of this project is, it is provided with Dancing LED system. A push-to-on switch is provided to change the dancing effect of the LED array. This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.
