Presented here is a handheld device that can be used to measure magnetic field using a Hall effect-based sensor. The device can be used in the physics lab for conducting various experiments on magnetism.
This compact shadow alarm unit is capable of sensing a moving shadow in a restricted area, and can be easily installed on a wall, window or door to protect your valuables from theft. Constant lighting is required in the confined area to detect the moving shadow.
This AVR microcontroller-based global positioning system (GPS) receiver can be used to find the exact location of a place and know its standard time.It provides the data corresponding to its position on international standard latitude-longitude basis and also the standard coordinated universal time (UTC) along with some more information received from the nearest satellite assigned for this purpose.
Presented here is a personal weather logger whose various transducers are used to log weather data such as humidity, atmospheric pressure and temperature. The data is transferred to PC where it is displayed as a graph for analysis.
Presented here is a Web-based water-level monitor and motor-pump controller using ATmega128 microcontroller, Ethernet controller ENC28J60 and TCP-IP protocol. The design involves the use of port-forwarding facility of broadband modem or router.
Presented here is a simple real-time clock with temperature logger. The project shows time, date and real-time temperature on the LCD. The logger records the maximum and minimum temperature for each day and can keep entries for 51 days.
When power requirement in certain areas increases, it tends to put an extra burden on the power station distributing power, which can lead to over and under voltage issues within those areas.
This project not only ensures under and over voltage cutoff, but also displays the mains voltage over LCD.
The concept of controlling various servo motors through Arduino Uno board is introduced here with a fun project called ‘namaste robot.’ The robot turns its head by 180° and scans people in its range using an ultrasonic module.
Here is a simple car-parking alarm circuit based on an AVR microcontroller and an ultrasonic module. The circuit will alert you while you are reversing your car for parking, if there is any obstacle, through an audio-visual alarm.
Morse code is a method of transmitting textual information as a series of on-off tones, lights or clicks that can be directly understood by a trained listener without using any special equipment. The International Morse Code encodes alphabets, numerals and a small set of punctuation and procedural signals as standardised sequences of short and long signals called ‘dots’ and ‘dashes,’ respectively.
In continuation of the embedded control applications explained in Part 2, let’s now examine the use of inbuilt functions of AVR ATmega8535 (such as output compare, ADC and UART) for various applications.
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 heater 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.
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).
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.
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.
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).
The regular 16×2 LCD can display characters of only certain dimensions. A graphical LCD (GLCD), on the other hand, can display custom graphics. GLCDs are therefore highly suitable for mobile and industrial applications.
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.
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.
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.
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.
This is a iBUTTON based secured system that uses a microcontroller. Whenever someone touches the iBUTTON using his own iBUTTON, the firmware inside AVR reads its unique ID and relay operates which in turn opens up the door.
The circuit that uses microcontroller AT89C51 can control four devices from a distance of upto 30 metres wirelessly. An LCD module is used to show the device number and preset control time at the transmitter module.
This is a circuit for a remote controlled 6 camera CCTV switcher that uses microcontroller, infrared module and other components to control the operation of 6 CCTV cameras. Controlling messages can be seen on a LCD module.
This circuit lets you operate your home appliances such as lights and water pump from your office or any remote location. The system also gives you voice acknowledgement of the appliance's status. It comprises microcontroller AT89C51, DTMF decoder MT8870, voice recording/ playback device APR9600.