Household PowerMeter

From OmgaV Wiki

The Household PowerMeter is a simple circuit with an AVR and a photodetector that detects flashes from the household wattmeter. The AVR software utilizes the on-chip UART serial port and sends arbitrary data to notify a host about the flashes. With this simple circuit and software one can log and analyze the total household power usage. A perl-script for logging the data into a mySQL database and a PHP page to display the data is also made.

Developers

• Pål Driveklepp

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Source code for ATmega16

/*
 
Source for software for atmega16 running at 8MHz sensing optical flashes and notifying host via USART
 
*/
 
 
 
#include <avr/io.h>
 
#include <avr/signal.h>
 
#include <avr/interrupt.h>
 
 
 
unsigned char pulsecounter = 0;
 
unsigned int uptime = 0;
 
unsigned int downtime = 0;
 
unsigned char sufficientdowntime = 0;
 
unsigned char sendpointer = 0;
 
 
 
void flash(unsigned char pattern);
 
void notify(void);
 
 
 
int foo = 0;
 
void delay(unsigned int delayet){
 
	for (unsigned int i = 0; i < delayet; i++){
 
		foo++;
 
	}
 
}
 
 
 
/* AD-converter conversion complete interrupt routine */
 
ISR(ADC_vect){
 
 
 
	int sample = (ADCW>>2);
 
 
 
	if ((sample>32)&&(sufficientdowntime)){
 
		uptime++;
 
		downtime = 0;
 
	}
 
	else {
 
		if (uptime){
 
			if((uptime>5)&&(uptime<60)){		//led flash duration was measured to 16 samples
 
				notify();
 
				pulsecounter++;
 
				PORTC = pulsecounter&0x01;
 
			}
 
		}
 
		uptime = 0;
 
		downtime++;
 
		if(downtime>60){
 
			sufficientdowntime = 1;
 
		}
 
		else{
 
			sufficientdowntime = 0;
 
		}
 
	}
 
 
 
	delay(2500);
 
	ADCSRA |= (1<<ADSC); 	//AD start conversion
 
 
 
}
 
 
 
int main(void){
 
 
 
	//LEDS
 
	DDRC = 0xFF;
 
	//ADC
 
	DDRA = 0x00;
 
	//serialport
 
	DDRD = 0xFF;
 
 
 
	//ADC READS ADC0 (pin1 on PortA)
 
	ADMUX = (1<<REFS0)|(1<<REFS1);
 
	//adc prefrences
 
	ADCSRA = (1<<ADEN)|(1<<ADSC)|(1<<ADIE)|(1<<ADPS2)|(1<<ADPS0);
 
 
 
	//setup USART
 
	UCSRB = (1<<TXEN);
 
	//8 databits see page 163 for writing to this register
 
	UCSRC = (1<<URSEL)|(3<<UCSZ0);//(1<<UCSZ1)|
 
	//baud-rate = 9600 (when mcu=8MHz)
 
	UBRRL = 51;
 
 
 
	flash(0x00);
 
 
 
	for (int i = 0; i < 256; i++){
 
		/* Wait for empty transmit buffer */
 
		while ( !( UCSRA & (1<<UDRE)) )
 
		;
 
		/* Put data into buffer, sends the data */
 
		UDR = i;
 
	}
 
 
 
 
 
	//ENABLES GLOBAL INTERRUPTS
 
	sei();
 
 
 
	while(1){
 
 
 
	}
 
 
 
}
 
 
 
/* flash arbitrary signal */
 
void flash(unsigned char pattern){
 
	for (int i = 0; i < 10; i++){
 
		PORTC = pattern;
 
		delay(60000);
 
		PORTC = 0xFF;
 
		delay(60000);
 
	}
 
}
 
 
 
/* send signal to host */
 
void notify(void){
 
 
 
	/* Wait for empty transmit buffer */
 
	while ( !( UCSRA & (1<<UDRE)) )
 
	;
 
 
 
	/* Put data into buffer, sends the data */
 
	UDR = 0x41 + sendpointer;	
 
 
 
	/* Wait for empty transmit buffer */
 
	while ( !( UCSRA & (1<<UDRE)) )
 
	;
 
	/* send end of text */
 
	UDR = 0x0A;
 
 
 
	if(sendpointer<25){
 
		sendpointer++;
 
	}
 
	else{
 
		sendpointer = 0;
 
	}
 
 
 
}

Perl script for logging to mySQL

#!/usr/bin/perl
 
#
 
#
 
# Author: Bruce S. Garlock
 
# Date:   2002-09-11
 
# Requirements: Device::SerialPort 0.12 (from cpan)
 
#
 
# Version: 0.1
 
#
 
#
 
# Description:  This perl script is for logging of data from a serial
 
# port, to a specified logfile.  The logfile can then be parsed with
 
# other programs for reporting purposes.
 
# 
 
# This program was written for specifically logging Multitech's
 
# MTASR2-203 T1 Router.  The router outputs text to the command
 
# port with 57.6k, 8-1-N, and No flow control.
 
#
 
#
 
 
 
use Device::SerialPort 0.12;
 
 
 
#$LOGDIR    = "/var/log";              # path to data file
 
#$LOGFILE   = "router.log";            # file name to output to
 
$PORT      = "/dev/ttyS0";          # port to watch
 
 
 
#
 
#
 
# Serial Settings
 
#
 
#
 
 
 
$ob = Device::SerialPort->new ($PORT) || die "Can't Open $PORT: $!";
 
$ob->baudrate(9600)   || die "failed setting baudrate";
 
$ob->parity("none")    || die "failed setting parity";
 
$ob->databits(8)       || die "failed setting databits";
 
$ob->handshake("none") || die "failed setting handshake";
 
$ob->write_settings    || die "no settings";
 
 
 
#
 
# Send a string to the port
 
#
 
 
 
$pass=$ob->write("AT");
 
sleep 1;
 
 
 
#
 
# open the logfile, and Port
 
#
 
 
 
#open(LOG,">>${LOGDIR}/${LOGFILE}")
 
#    ||die "can't open smdr file $LOGDIR/$LOGFILE for append: $SUB $!\n";
 
#
 
open(DEV, "<$PORT") 
 
    || die "Cannot open $PORT: $_";
 
 
 
#select(LOG), $| = 1;      # set nonbufferd mode
 
#
 
#
 
# Loop forver, logging data to the log file
 
#
 
 
 
use DBI;
 
 
 
$username = '*****';$password = '******';$database = 
 
'******';$hostname = 'localhost';
 
$dbh = DBI->connect("dbi:mysql:database=$database;" .
 
  "host=$hostname;port=3306", $username, $password);
 
 
 
 
 
 
 
 
 
$watted = 0;
 
$SQL= "INSERT INTO ticktable VALUES ( '' , NOW( ) , '26')";
 
 
 
 
 
while($_ = <DEV>){        # print input device to file
 
	if (($_ eq "X\n") || ($_ eq "Y\n") || ($_ eq "Z\n")){
 
		$watted = 1;
 
		print "reached end!";
 
	}
 
	else {
 
		if($watted>0){
 
			$dbh = DBI->connect("dbi:mysql:database=$database;" .
 
			"host=$hostname;port=3306", $username, $password);
 
			$InsertRecord = $dbh->do($SQL);
 
			if ($InsertRecord){
 
				print "SQL success!";
 
			}
 
			else{
 
				print "SQL failed!: $DBI::errstr";
 
			}
 
			$watted = 0;
 
		}
 
	}
 
	print $_;
 
}
 
 
 
undef $ob;