Arduino based breath analyzer

This is a simple breath analyzer based on a gas sensor (MQ-3 from Sparkfun) that is highly sensitive to alcohol. The author demonstrates how to interface the gas sensor to Arduino to sense the content of alcohol in your breath. This project does not display the numeric value of the alcohol concentration on any LCD, but it has a series of 11 LEDs (green through red) that gives the strength of the alcohol content.

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Motion detection alarm using a PIR sensor module with a PIC Microcontroller

Introduction This project describes a motion sensor alarm based on a Passive Infra-Red (PIR) sensor module. There are many vendors that manufacture the PIR sensor modules and almost all of them are pretty much the same in function. They have a single output that goes high (or low, based on specification) when the motion is detected. In this project, a PIC12F635 microcontroller continuously monitors the output from the sensor module and turns a buzzer on when it goes active. Theory Certain crystalline materials have the property to generate a surface electric charge when exposed to thermal infrared radiation. This phenomenon

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Lab 8: Asynchronous serial communication

Description The PIC16F628A microcontroller has a built in Universal Synchronous Asynchronous Receiver Transmitter (USART) hardware that allows to communicate with a wide range of serial devices such as memory chips, LCDs, personal computers, etc. The USART module has two modes of operation: synchronous (requires a synchronized clock between the transmitter and receiver) and asynchronous (no synchronization clock required). As the asynchronous mode is more popular, we will focus today’s lab session on this and will establish a two way serial data link between the PIC microcontroller and a PC. Required Theory Serial communications are used in microcontroller-based systems, mostly due

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Power usage monitor using Atmel AVR

This project uses Atmega168 microcontroller to compute the power usage at home and logs it to an SD card. It has a graphical LCD display too that shows the power usage as a strip chart. Besides, the voltage and current waveforms can also be displayed on the LCD. The current is measured using a pair of current transformers whereas the voltage is measured using a 2000:1 voltage divider network. An LMC6484AIN quad op-amp and an AD623AN instrumentation amplifier are also used for signal amplification from the current sensor and the voltage divider.

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Running message display project for Christmas

Introduction As Christmas is coming people have already lightened their houses. I thought of doing something different for this Christmas besides the festive Christmas lights. I made a running message display using LEDs, and thought of sharing it with you. This is a very simple running message display project that displays the message ‘MERRY XMAS’, where each letter is created with 5mm diameter red-color LEDs. The 9 letters in the message are individually turned on or off through a PIC16F688 microcontroller’s I/O pins. Therefore, a variety of display patterns can be generated through the software inside the microcontroller.

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