post details Interfacing-Seven-Segment-LED-Display-8051-Microcontroller | Common-Anode-Common-Cathode-LED-8051-89C52-89C52-AT89S51-AT89S52-AT89S52
Interface Seven Segment LED Display : 8051 MCU
Interfacing Seven Segment LED Display With 8051 Microcontroller Family Models
Atmel, NXP, Philips, 8051, 8052, 89C51, 89C52, 89S51, 89s52, 89C1051, 89C1051, 89C2051, AT89C4051, AT89S8252,l AT89C1051, AT89C2051, AT89C4051,P89C51RB+, P89C51RC+, P89C51RD+, P89C51RB2Hxx, P89C51RC2Hxx, P89C51RD2Hxx, P89C660, P89C662, P89C664, P89C668, P89C669, P89C51RA2xx, P89C51RB2xx, P89C51RC2xx, P89C51RD2xx, P89C60X2, P89C61X2,P89LV51RB2, P89LV51RC2, P89LV51RD2, P89V51RB2, P89V51RC2, P89V51RD2, P89V660, P89V662, P89V664.
Introduction 7 or Seven Segment LED Display Boards:
The Light Emitting Diode (LED) can be seen every where in all kinds of applications example where we have to show the numeric status of any system example our CD player showing the current running track, microwave oven is showing the time elapsed, temperature control system shows temperature all is done with the help of LED a tiny bulbs. When these bulbs are shaped into seven and shaped into Seven Segment LED Display. Seven Segment Displays contains the fixed arrangement of the LEDs in Eight(8) and a Dot (.) with a Common Anode or Common Cathode. The marvelous move is this we can use this arrangement in that manner that we can create numeric character of our own choice from 0-9. Switching on and off of the LEDs any number can be created and with the help of 8051 Microcontroller. A Simple Diagram is given here.
Types OF Seven Segment LED Display :
A Seven Segment LED 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. Seven segment uses seven LED’s to show the digits from 0-9 and the eighth LED is used for the dot.  Seven Segment LED Display are commonly available in the market at very nominal cost usually 6 Rs each in Indian market. There are two types of displays are available in the embedded fields Common Anode Seven Segment LED Display or CA It means all the 8 anode legs uses only one cathode negative voltage signal which is common. Common Cathode Seven Segment LED Display or CC The common leg for all the cathode is of Anode type means positive voltage.
Interfacing Seven Segment LED Display With 8051 Microcontroller:
Interfacing seven segment display with 8051 microcontroller is very simple but little bit tricky. In old days developer used a decoder IC to display numeric character at seven segment led but now Microcontroller has the decoder itself to display numeric character. Common anode display are most suitable for interfacing with 8051 Microcontroller because its port pins can sink current better than sourcing it. Connect the a to g pins of microcontroller and the eight dot pin of seven segment display to the 8-bit port of 8051 microcontroller. To display numeric send the respective code to the port of the 8051 Microcontroller and send another hex to display another number on the display. Circuit is given below.