Skip to main content

EnerJar: A Digital Energy Meter

This project won the grand prize of 2008 Green Gadgets Design competition. It measures the power consumption of an electrical gadget with high accuracy. The project uses PIC16F877A microcontroller to compute the power and shows the output on a 4-digit multiplexed seven segment display.


The power consumed by an electrical appliance is simply the product of voltage across the appliance and the current drawn by it. Voltage measurement is pretty straight forward. Using a resistor divider network, 120 V can be converted down to below 5 V, and can be read through ADC port. However, PIC cannot measure the current directly, it must be converted to voltage first. This is done by a low shunt resistance. This voltage drop across the shunt resistance is too small and requires a precision instrumentation amplifier to boost it to appropriate level.



The firmware for PIC is available to download.



Read Rest of the Project

Comments

  1. sir, can you send me the coding and other details to my mail..i am doing the same project...pls kindly help me.. my mail id is prakashgkm@gmail.com.. thanks

    ReplyDelete
  2. i want the code too... tyo_red_hot@yahoo.co.uk

    FYI: the enerjar.net is error

    ReplyDelete

Post a Comment

Popular posts from this blog

Contact less tachometer using PIC16F628A

Introduction
Tachometer is a device that gives you the information about the rotational speed of any shaft or disc. It usually measures the speed in revolutions per minute (RPM). Today we are going to make a simple tachometer that could measure the rotation speed of a disk without making any physical contact (that's why it is contact less) with the rotating object. The range of this tachometer is 0 - 9999 RPM and displays the RPM on a multiplexed 4-digit seven-segment display. Of course, we are going to do this project on our usual PIC16F628A development board.

Infrared sensor
Contact-less measurement of RPM will be achieved through an IR sensor. An IR diode will send a beam of infrared towards the rotating disc, and any reflected pulse will be received by a photo diode. The resistance of a photo diode drops drastically when exposed to infrared. An infrared is reflected by a white surface and absorbed by the dark ones. The test disc for this project is shown below. You can see the …

Experiment No. 2 : Push Button and Seven Segment Display Interface

In this experiment, we will program the PIC16F628A as an UP/DOWN Decade Counter. The count value will be displayed on a Seven-Segment Display and will be incremented/decremented by two push buttons on the board.

Experimental Setup:
The board has built in interface for a multiplexed 4-digit seven segment display (HS-5461AS2 from www.futurlec.com).We will select only one digit by connecting a Digit Select pin to Vcc, as shown in figure below. A black jumper wire is used for this purpose. The seven segments will be driven through PORTB (already wired on the board). Connect Push Buttons (PB3 and PB4) to RA1 and RA0 female headers using jumper wires.


PIC16F628A Development Board

The development board we are going to make for our experimental microcontroller PIC16F628A will look like this. Here are the features it is going to have:
Access to all I/O pins through female header pins4 Push Buttons for Input4 LEDs for OutputAn LCD Interface PortA 4-digit Seven-Segment Display InterfaceLCD Backlight Switch and Contrast AdjustmentICSP Programming (Very Important)