Timers are used in many different applications for example in Industrial Applications, to switch ON or switch OFF any device or a machine load for a specific period of time.  In the same way the timers are used in Domestic Appliances like in Air Conditioners, Microwave Ovens, Washing Machines, Food Processors etc. The applications for the timers could also be seen in Military Applications and Space Applications, to trigger any Bomb or a Missile or to ignite booster rockets for lift offs at a specific time. Here the given project demonstrates the fully featured and customized timer built using AVR Microcontroller ATMega32.  

To interface 8-bit DAC with AVR microcontroller ATMega32 and generate different waveforms like Square Wave, Sine Wave, Triangular Wave, Staircase Wave and Saw-tooth Wave. To generate different Analog waveforms using AVR microcontroller it is required to interface a DAC that will convert the Digital inputs given by microcontroller into corresponding Analog outputs and thus it generates different analog waveforms. The DAC output is current equivalent of digital input. So to convert it in to voltage a current to voltage converter is required. 

The circuit presented here demonstrates how to generate Audible Frequency from an AVR Microcontroller. The output of Microcontroller is always digital so to generate audible sound at the outset first it needs to be converted into Analog. A DAC (Digital to Analog Converter) is used for this purpose. Microcontroller generates sine wave of Audible Frequency using DAC. This sine wave is further given to Audio Amplifier that drives speaker. Microcontroller generates sine wave of fix frequency continuously. So we can hear an audible tone of fix frequency 

In many of the applications it is required to alter the direction of DC motor instantly. Like in washing machine, mixer, drilling machine winding – rewinding machine etc. Changing the direction of DC motor using joystick is most suitable and handy method.In industries the joystick control is most preferable way to control machinery that is operated with DC motor. The best example is 3 axis or 2 axis DC motor operated crane. In this, 3 (or 2) DC motors  moves crane up or down, rotate it left or right using 3 (or 2) joysticks 

GSM stands for Global System for Mobile Communications. It is a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones.  A Modem is a device which modulates and demodulates signals as required to meet the communication requirements .It modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. A GSM Modem is a device that modulates and demodulates the GSM signals and in this particular case 2G signals. The modem we are using is SIMCOM SIM300. It is a Tri-band GSM/GPRS Modem as it can detect and operate at three frequencies (EGSM 900 MHz, DCS 1800 MHz and PCS1900 Mhz). Default operating frequencies are EGSM 900MHz and DCS 1800MHz.Sim300 is a widely used in many projects and hence many variants of development boards for this have been developed. 

Summary Updating with the era of technology, the new microcontrollers are coming with lots of inbuilt peripherals and features. These inbuilt peripherals and features not only reduce the cost of additional circuits to be used with the controller but also provide an ease to interface additional devices (such as Modems etc) directly with the microcontroller. The…

AVR (ATmega32) contains some in-built registers for TWI communication which not only reduce the level of complexity but also make the whole communication process smooth. These registers have been explained in this tutorial. 1.        TWBR (TWI Bit Rate Register) : TWBR7 TWBR6 TWBR5 TWBR4 TWBR3 TWBR2 TWBR1 TWBR0   This register is used in master…

This article explores the TWI interfacing between two ATmega32 controllers. Readers are advised to go through TWI Communication and TWI registers[[wysiwyg_imageupload::]]of ATmega32 before going further. Generally modes 1 & 3 and modes 2 & 4 are used together. This article explains the use of these four modes by an experiment.To establish the communication between two ATmega32 using TWI interface. First the Master starts by sending data then the slave transmits complement of the received data to the master. When the Master receives the complemented data, it shifts the original data to left. This process of transmitting and receiving continues. As the data value reaches 0x80 the whole process is repeated. At the starting, value of the original data is 0x01. The received value is displayed on PORTB at both the ends.