Interfacing to Microcontroller 8051

Here we discus about 8051 Microcontroller Interfacing defined as transferring data between microcontrollers and interfacing peripherals such as sensors, keypads, microprocessors, analog to digital converters or ADC, LCD displays, motors, external memories, even with other microcontrollers, some other interfacing peripheral devices and so on or input devices and output devices. These devices that are interfacing with 8051 microcontroller are used for performing special tasks or functions are called as interfacing devices.

Interfacing is a technique that has been developed and being used to solve many composite problems in circuit designing with appropriate features, reliability, availability, cost, power consumption, size, weight, and so on. To facilitate multiple features with simple circuits, microcontroller is interfaced with devices such as ADC, keypad, LCD display and so on.

Interfacing Seven Segment Display with 8051

A seven segment display module is an electronic device used to display digital numbers and it is made up of seven LED segments. Because of the small size of the LEDs, it is really easy for a number of them to be connected together to make a unit like seven segment display. In the seven segment display module, seven LED s are arranged in a rectangle. Sometimes, an additional LED is seen in a seven segment display unit which is meant for displaying a decimal point.

Each LED segment has one of its pins brought out of the rectangular package. Other pins are connected together to a common terminal. Seven segment displays can only display 0 to 9 numbers. These seven LEDs indicate seven segments of the numbers and a dot point. Seven segment displays are seen associated with a great number of devices such as clocks, digital home appliances, signal boards on roads etc.

Types of Seven segment displays

Seven segment displays come up with two different configurations. They are the common Anode and a Common cathode. One pin each from each segment is connected to a common terminal. According to the pins which are connected to the common terminal, the seven segment display is categorized as a common anode and common cathode.

Common Cathode 7-segment display

As the name indicates, its cathode is connected to a common terminal. Below is the schematic diagram to indicate its common cathode structure. It should be connected to the ground while operating the display. If a high voltage is given to the anode, then it will turn on the corresponding segment.