keypad

Interfacing Keypad with 8051 Microcontroller using Keil C

Matrix Keypad Matrix Keypads are commonly used in calculators, telephones etc where a number of input switches are required. We know that matrix keypad is made by arranging push button switches in row and columns. In the straight forward way to connect a 4x4 keypad (16 switches) to a microcontroller we need 16 inputs pins. But by connecting switches in the following way we can read the status of each switch using 8 pins of the microcontroller. The status of each [...]

Servo Motor

Interfacing Servo Motor with 8051 using Keil C

A servo motor uses servo mechanism, which is a closed loop mechanism that uses position feedback to control the precise angular position of the shaft. Stepper Motors, which is an open loop system can also be used for precise angular control. But Servo Motors are preferred in angular motion applications such as robotic arm. Moreover controlling of servo motors are very simple, easy and needs no extra hardware like stepper motor. Usually hobby circuit servo motors have three wires. Two of [...]

Push Button Switch

Using Push Button Switch with 8051 and Keil C – AT89C51

This tutorial is for beginners in the field of microcontroller. In this case the microcontroller is AT89C51, a reprogrammable derivative of 8051. This purpose of this tutorial is to familiarize with the use of push button switch with the microcontroller. It will be useful whenever a decision is to be made according to the press of a switch. If you are not yet started with 8051 with Keil C please refer this tutorial Blinking Led using 8051 and Keil C. Circuit Diagram Push button switch is connected [...]