December | 2010 | Embedded Lab

Monthly Archives: December 2010

Regulated power supply for embedded systems

Posted on December 21, 2010 by R-B 4 comments

Power is an important aspect of all embedded systems. Nothing works without electric power. Depending upon the type of applications, several options for power are available. For example, if the system doesn’t need to be portable, it can be powered directly from the wall source using AC adaptors. AC adaptors are cheap and easily available at any electronics store. They are used to power a bunch of electronics gadgets at home, like radios, answering machines, wireless routers, etc. They also come with mobile phones as chargers. They convert the high voltage AC in the wall socket to low voltage DC

Looking for expanding RAM for your Atmega128?

Posted on December 20, 2010 by R-B Leave a comment

An Atmega128 microcontroller has got 4K of built in static RAM, which is pretty enough for small and medium range projects that do not involve huge amount of data processing. But if you think you need more than that for your application, you can expand it by adding an external RAM chip. This article shows how you can expand the RAM capacity of Atmega128 up to 64K.

Arduino based breath analyzer

Posted on December 20, 2010 by R-B One comment

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.

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

Posted on December 17, 2010 by R-B 38 comments

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

Lab 8: Asynchronous serial communication

Posted on December 14, 2010 by R-B 26 comments

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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