A tachometer is nothing but a simple electronic digital transducer. Normally, it is used for measuring the speed of a rotating shaft. The number of revolutions per minute (rpm) is valuable information for understanding any rotational system. For example, there is an optimum speed for drilling a particular-size hole in a particular metal piece; there is an ideal sanding disk speed that depends on the material being finished. You may also want to measure the speed of fans you use.
Here is an easy-to-construct temperature indicator-cum-controller that can be interfaced with a heaterís coil to maintain the ambient room temperature. The controller is based on Atmega8535 microcontroller, which makes it dynamic and faster, and uses an LCD module to display and two keys to increase or decrease the set values.
EEPROM Interface for Beginners
Electronic systems today incorporate a number of peripheral ICs that have to communicate with each other and the outside world. To maximise hardware efficiencyand simplify circuit design, Philips developed a simple bidirectional two-wire communication interface between components residing on the same circuit board. This interface is referred to as two-wire interface (TWI) or I2C (inter-integrated circuit).
Ethernet Interface for Automation Systems
Communication with remotely located automation systems is possible via the Internet. A physical communication port with a network is required for this communication. An Ethernet interface can be used for that purpose.
Part 1 of 3 USING AVR MICROCONTROLLERS FOR PROJECTS
The AVR 8535 microcontroller and its new version ATmega8535 are versatile, high-performance but low-cost chips. This article series covers typical applications of this processor illustrating its power and cost-effectiveness in an embedded system.
Part 2 of 3 Using AVR Microcontroller for Projects
In the first part of this article, we had described the main features of the AVR microcontroller and the hardware/software required for an AT-PROG programmer board interfaced to the printer port of a PC. Further, we explained the methods for message display on a liquid crystal display (LCD).
Microcontroller-Based Clock Using DS1307
Digital wall clocks, table clocks and desk clocks with pointer or LCD display are readily available in the market. Here we present a clock that can be built in a small budget using AT89C2051 microcontroller. Additional feature of the clock is that the time display is visible even in the dark.
Dynamic Display Using LED Strip
Here we describe a microcontroller-based dynamic display system using LED strip that can be used for advertising message display. The display works by flashing characters sequentially and then the entire text together.
Time-Controlled Switch Using PIC16F72
A time-controlled switch is an automatic timer switch that turns an appliance ‘on’ for the desired time duration. After the preset time duration, the timer automatically switches off, disconnecting the appliance from the power supply.
Moving Message Display On LCD
Here’s an AVR-based moving-message display that uses a 16×2 LCD display incorporating HD44780. The 16×2 LCD can display 16 characters per line and there are two such lines.
RFID-Based Automatic Vehicle Parking System
Radio-frequency identification (RFID) is an automatic identification method wherein the data stored on RFID tags or transponders is remotely retrieved. The RFID tag is a device that can be attached to or incorporated into a product, animal or person for identification and tracking using radio waves.
RFID-based Security System
This circuit is a security system that uses RF tags as security credentials. It comprises of a microcontroller AT89C52 and an RFID reader.