The door bell seems like a simple project but it’s not! There is one major difficulty it’s to generate a sine wave via Pulse Width Modulation.
ATMega8 Door Bell – [Link]
Sometimes it’s handy to have a message display when persons enter a specific area. Having the message appear only when someone approaches brings more attention it, and can be useful for holiday displays, directions or warnings. In this project by Jer from Volts and Bytes, an Atmega8 is used to activate a Sure Electronics 0832 LED matrix display when motion is detected by the attached PIR sensor.
The C source and supporting files are available in this zip file.
PIR controlled LED matrix display – [Link]
Using graphic LCD in a project gives itreally a good look and flexibility of displaying different characters and shapes. But, the graphic LCDs are quite costly.
The NOKIA 3310 LCD provides a really low-cost solution to add a small graphic display into your project and also good for learning purpose. The LCD is SPI bus compatible, saving many pins for other uses. It operates at 3.3v.
NOKIA 3310 LCD interfacing with ATmega8 – [Link]
Now, here I’m presenting one application with the same LCD: Designing a thermometer using DS1621 temperature sensor IC. DS1621 is 8-pin sensor from Maxim, with temp range of -55 to +125 degree C, which can be interfaced with microcontroller over two-wire serial i2c bus. It has operating voltage range from 2.7 to 5.5v. I’m operating it here at 3.3v, same as the one driving the LCD and ATmega8. DS1621 doesn’t require any external components to measure temperature. It has got continuous or one-shot temperature reading capability to save power.
Thermometer using DS1621 and Nokia 3310 LCD interfaced with ATmega8 – [Link]
Here is a very simple project of controlling a small DC-motor (taken from an old personal cassette player) with ATmega8. The ATmega8 is having three PWM channels, out of which two are used here. PWM waveforms are fed to MOSFET (RFD3055) H-bridge. Here, direction is controlled using a two-position toggle switch and speed of the motor is controlled by two push-buttons, one for increasing the speed and other for reducing.
Simple PWM DC motor control using MOSFET H-Bridge with AVR ATmega8 – [Link]
Here is my project on interfacing of SD Card (microSD). microSD cards are available very cheap nowadays, a great option for having a huge memory in any embedded system project. It is compatible with SPI bus, so the interfacing is easy. SD card adapters are also easily available in market, one can easily make a bread-board adapter by soldering few pins on it. Following figures show the SD card pin-out & the bread-board adapter design by soldering 7-pins of a breakout header on the microSD adapter
SD/SDHC Card Interfacing with ATmega8 /32 (FAT32 implementation) – [Link]
This project use a PC for GUI display and AVR Based data converter board. The circuit is built with the ATmega8. The GUI programming with Visual Basic to receive data from ATMega8 vai RS232. The ATMega8 chip has the onchip 10-bit resolution A/D Converter. Temperature sensor are connected to the 6 channels ADC input. You can connect up to 8 sensors with the ATmega8 TQFP package.
Data Acquisition System using ATmega8 - [Link]
Gratuitous device tracks door position with laser-printed linear quadrature encoder; commands servo to aim projector at door. Projector is a thrift store 50mm camera lens, teensy scrap of laser-printed transparency, and a 1W Cree LED. Electronics is an Atmega 8 with two Futurlec reflective IR sensors and PWM output to the servo. Source code in R-ULAV tree, available at http://rocket.jonh.net
Dynamic tracking door nameplate projector - [Link]
This Arduino can be used for old school prototyping as well. Just use it as a standard ATmega8 and program it with the ISP connector. And it is one of the cheapest Arduino boards, that you can get. Arduino is a great prototyping platform and most of you probably know already about it. If not, check out the Arduino pages and the Arduino playground and dive into it.
Arduino Breadboard Clone – [Link]