PIC Projects | Embedded Lab

Category Archives: PIC Projects

A new multi-function power supply unit for my Embedded Lab

Posted on March 26, 2011 by R-B 39 comments

One important parameter in embedded system designing is power consumption. This parameter is directly related to the battery lifetime, if the system is to be powered from a battery. In order to determine the power rating of your designed system, you need to know how much current the system draws from the source at a given voltage. While working on my projects, I usually measure current by placing an external ammeter in series with the current’s return path. This is not always convenient to do, and so I thought of making a special power supply unit for my lab that

A simple spectrum analyzer using dsPIC30F4011

Posted on March 16, 2011 by R-B One comment

This project (posted on hobbydebraj) describes a simple spectrum analyzer based on a dsPIC30F4011 microcontroller. It uses Microchip’s FFT library codes to calculate the frequency spectrum of an input signal. The signal conditioning is achieved by a TL084 Op-amp IC. The peaks of spectrum are displayed on a graphics LCD.

2-Wire Keypad Interface Using a 555 Timer

Posted on February 20, 2011 by R-B 23 comments

Keypads are a very commonly used input device in microcontroller-based systems. In a keypad, multiple switches are arranged in rows and columns so that they could be interfaced to a microcontroller with a minimum number of I/O pins. For example, a 12-key keypad is arranged in a 4×3 format, which allows to interface the 12 keys to a microcontroller with only 7 connections. The location of each key on the keypad is defined by two coordinates: the row and the column. When a key is pressed, it connects its row with its column. The microcontroller must scan all the rows

A contact-less digital tachometer based on optical sensors

Posted on February 10, 2011 by R-B Leave a comment

A tachometer is use to measure the rotations per minute (RPM) of a moving shaft or a motor. An example is a digital tachometer in a car that gives the RPM of the engine. This tutorial shows how to build a digital tachometer using a microcontroller and optical sensors. The sensor unit consists of an IR LED that transmits infrared light and a photo diode that receives the light. This project uses a computer fan to demonstrate the technique. The fan is placed between the IR LED and the photo diode so that the blades of the moving fan interrupts

Heart rate measurement from fingertip

Posted on February 5, 2011 by R-B 841 comments

Introduction Heart rate measurement indicates the soundness of the human cardiovascular system. This project demonstrates a technique to measure the heart rate by sensing the variation of the blood volume inside a finger artery, which is caused by the pumping action of the heart. It consists of an infrared LED that transmits an IR signal through the fingertip of the subject. A part of this infrared light is reflected by the blood cells. The reflected signal is detected by a photo diode sensor. The changing blood volume with heartbeat results in a train of pulses at the output of the photo diode,

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