07-07-2012, 11:51 AM
Interfacing of 8051 Microcontroller with 7-segment LED
[attachment=27070]
ABSTRACT:-
This report introduces to the very basic operation of taking an output from the microcontroller AT89C51. It demonstrates the principle behind interfacing LEDs with 8051 microcontroller. Here we have demonstrated the aforesaid principles by blinking LEDs continuously i.e., switching them on and off.
ARCHITECTURE OF 8051 MICROCONTROLLER:-
The figure shows block diagram of AT89C51 microcontroller. The AT89C51 provides the following standard features: 4K bytes of flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes:
1. Idle mode:
In idle mode, the CPU puts itself to sleep while all the on-chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special function registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset.
2. Power-down mode:
In the power-down mode, the oscillator is stopped and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and special function registers retain their values until the power-down mode is terminated. The only exit from a power-down is a hardware reset. The reset should not be activated before Vcc is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.
INTRODUCTION TO 7-SEGMENT LED:-
A 7-segment consists of eight LEDs which are aligned in a manner so as to display digits from 0 to 9 when proper combination of LED is switched on. 7-segment uses seven LEDs to display digits from 0 to 9 and the eighth LED is used for the dot. The parts on a 7-segment LED display board are: a 7-segment LED display chip, a latch chip and a display decoder chip. A typical 7-segment looks like as shown in the figure below.
[attachment=27070]
ABSTRACT:-
This report introduces to the very basic operation of taking an output from the microcontroller AT89C51. It demonstrates the principle behind interfacing LEDs with 8051 microcontroller. Here we have demonstrated the aforesaid principles by blinking LEDs continuously i.e., switching them on and off.
ARCHITECTURE OF 8051 MICROCONTROLLER:-
The figure shows block diagram of AT89C51 microcontroller. The AT89C51 provides the following standard features: 4K bytes of flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes:
1. Idle mode:
In idle mode, the CPU puts itself to sleep while all the on-chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special function registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset.
2. Power-down mode:
In the power-down mode, the oscillator is stopped and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and special function registers retain their values until the power-down mode is terminated. The only exit from a power-down is a hardware reset. The reset should not be activated before Vcc is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.
INTRODUCTION TO 7-SEGMENT LED:-
A 7-segment consists of eight LEDs which are aligned in a manner so as to display digits from 0 to 9 when proper combination of LED is switched on. 7-segment uses seven LEDs to display digits from 0 to 9 and the eighth LED is used for the dot. The parts on a 7-segment LED display board are: a 7-segment LED display chip, a latch chip and a display decoder chip. A typical 7-segment looks like as shown in the figure below.