Well after setting the original system up it only lasted 4 days before the battery went flat. It appears I shouldn’t leave the radio on all the time on the remote node otherwise it chews through the battery very quickly. So I searched through the JeeNode examples to look for low power options.<\/p>\n
One of the issues with low power mode for the ATmega is that it doesn’t maintain time accuracy, and the JeeNode doesn’t have a RTC (I’m thinking of getting one). So the best thing I think I can do is to just turn the radio off when not used. The other option is to tone down update rate, I’ll probably look at that after I’ve collected more baseline data.<\/p>\n
So after working with the RadioBlip<\/a> code from the Jeelib examples I came up with this:<\/p>\n #include <Ports.h> #define SEND_MODE 1<\/p>\n volatile bool adcDone;<\/p>\n \/\/ for low-noise\/-power ADC readouts, we’ll use ADC completion interrupts \/\/ this must be defined since we’re using the watchdog for low-power waiting static byte vccRead (byte count =4) { class Port; void setup() { \/\/rf12_config(); void loop () {<\/p>\n static boolean ledOn = false; \/\/ Variable to indicate LED status void ledBlink() { nBlinks++; byte vcc = vccRead(); last = time; static void wattSend(long watts,long blinks, long vcc) { The code also contains parts which measures the Vcc voltage so I can determine when the battery pack is starting to get low.<\/p>\n The receiver code needed to change too. I wanted to include not just power, but the number of blinks and the new Vcc measurement. Here is the new code:<\/p>\n #include <Ports.h> void setup() { void loop() { if (packet.lang == LANG_ELECTRICITY) { static void wattShow(long watts,long blinks,long vcc) { I also changed the receiving Perl script to put the data into a MySQL database instead of dumping to a text file.<\/p>\n use strict; use Win32::SerialPort qw( :STAT 0.19 ); my $port = Win32::SerialPort->new(‘COM9’);<\/p>\n my $time = time;<\/p>\n # MYSQL CONFIG VARIABLES if( ! defined($port) ) { my $outfd; my $output = select(STDOUT); $port->initialize();<\/p>\n $port->baudrate(57600); while(1) { #my $content = get $pvoutput;<\/p>\n my $sth=$dbh->prepare(“INSERT INTO $tablename VALUES(‘$thedate’,’$1′,’$2′,’$3′)”) This is the database structure:<\/p>\n \n— Server version: 5.5.24 — Table structure for table `data` Now finally I wanted to graph the data but I haven’t found a good graph program for the front-end. So I’m using PVoutput, I’m not sure how it will work but I wrote this script to dump usage data for 5 minute intervals. It calculates averages and power usage data for the last 5 minute period, I initiate it using cron.<\/p>\n use strict; use POSIX qw\/strftime\/;<\/p>\n # MYSQL CONFIG VARIABLES my $thetime=int(time() \/ 300) * 300; my $dbh = DBI->connect(‘DBI:mysql:’.$database.’;host=’.$host, $user, $pw, { RaiseError => 1});<\/p>\n my $sth=$dbh->prepare(“select DATE_FORMAT(MIN(date), ‘%Y-%m-%d’) as day, max(blinks)-min(blinks) as Wh, round(avg(watts)) as Watts, Date_format(Min(date), ‘%H:%i’) as time from data where date > ‘$thetime_5string’ AND date < ‘$thetimestring’ GROUP BY ( 12 * HOUR( date ) + FLOOR( MINUTE( date ) \/ 5 ));”) my $url = “http:\/\/pvoutput.org\/service\/r2\/addstatus.jsp”;<\/p>\n my $ua = LWP::UserAgent->new( timeout => 120 ); my $req = POST $url, [ my $content = $ua->request($req)->as_string;<\/p>\n print $content;<\/p><\/blockquote>\n I’ll post a link to my PVOutput data once it looks ok.<\/p>\n","protected":false},"excerpt":{"rendered":" Well after setting the original system up it only lasted 4 days before the battery went flat. It appears I shouldn’t leave the radio on all the time on the remote node otherwise it chews through the battery very quickly. … Continue reading
\n#include <RF12.h>
\n#include <avr\/sleep.h>
\n#include “kWh.h”<\/p>\n
\nISR(ADC_vect) { adcDone = true; }<\/p>\n
\nISR(WDT_vect) { Sleepy::watchdogEvent(); }<\/p>\n
\nset_sleep_mode(SLEEP_MODE_ADC);
\nADMUX = bit(REFS0) | 14; \/\/ use VCC as AREF and internal bandgap as input
\nbitSet(ADCSRA, ADIE);
\nwhile (count– > 0) {
\nadcDone = false;
\nwhile (!adcDone)
\nsleep_mode();
\n}
\nbitClear(ADCSRA, ADIE);
\n\/\/ convert ADC readings to fit in one byte, i.e. 20 mV steps:
\n\/\/\u00a0 1.0V = 0, 1.8V = 40, 3.3V = 115, 5.0V = 200, 6.0V = 250
\nreturn (55U * 1024U) \/ (ADC + 1) – 50;
\n}<\/p>\n
\nPort inputPort(1);
\nstatic unsigned long last;
\nstatic unsigned long totalblinks;<\/p>\n
\nSerial.begin(57600);
\ninputPort.mode2(INPUT); \/\/ Set AIO mode as input
\ninputPort.digiWrite2(1); \/\/ Activate pull-up resistor for AIO<\/p>\n
\nrf12_config(); \/\/ Apparently this is necessary
\nrf12_easyInit(1); \/\/ Send value at most every 3 seconds
\nlast = millis();
\nrf12_control(0xC040); \/\/ set low-battery level to 2.2V i.s.o. 3.1V
\nrf12_sleep(RF12_SLEEP);
\n}<\/p>\n
\nint data = inputPort.anaRead();
\nrf12_easyPoll();
\nif (!ledOn && data > 760) {\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0\/\/ After testing I found the switching point was 750
\nledOn = true;
\n} else if (ledOn && data < 740) {
\nledOn = false;
\nledBlink();
\ntotalblinks++;
\n}
\n}<\/p>\n
\nstatic int nBlinks = 0;
\nunsigned long time = millis();
\nunsigned long interval = time – last;<\/p>\n
\nif (interval < 0) { \/\/ millis() overflow
\nlast = time;
\nnBlinks = 0;
\n} else if (interval > 1000) { \/\/ 1+ sec passed
\n\/\/ Blinks are 1000 per kWh, or 1 Wh each
\n\/\/ One hour has 3.6M milliseconds
\nlong watts = nBlinks * 1 * 3.6E6 \/ interval;<\/p>\n
\nwattSend(watts,totalblinks,vcc);<\/p>\n
\nnBlinks = 0;
\n}
\n}<\/p>\n
\nPacket_t packet;
\npacket.lang = LANG_ELECTRICITY;
\npacket.mesg = MESG_ELEC_CURRENT;
\npacket.data = watts;
\npacket.blinks = blinks;
\npacket.vcc = vcc;
\nrf12_sleep(RF12_WAKEUP);
\nwhile (!rf12_canSend())
\nrf12_recvDone();
\nrf12_sendStart(0, &packet, sizeof packet);
\nrf12_sendWait(SEND_MODE);
\ndelay(10);
\nrf12_sleep(RF12_SLEEP);
\n}<\/p><\/blockquote>\n
\n#include <RF12.h>
\n#include “kWh.h”<\/p>\n
\nSerial.begin(57600);
\n\/\/rf12_config();
\nrf12_config();
\n}<\/p>\n
\nif (rf12_recvDone() && rf12_crc == 0 && rf12_len == sizeof (Packet_t)) {
\nPacket_t packet = *(Packet_t *) rf12_data;<\/p>\n
\nif (packet.mesg == MESG_ELEC_CURRENT) {
\nwattShow(packet.data,packet.blinks,packet.vcc);
\n}
\n}
\n}
\nelse {
\ndelay(10);
\n}
\n}<\/p>\n
\nSerial.print(watts);
\nSerial.print(“,”);
\nSerial.print(blinks);
\nSerial.print(“,”);
\nSerial.println(vcc);
\n}<\/p><\/blockquote>\n
\nuse warnings;
\nuse DBI;
\nuse LWP::Simple;<\/p>\n
\nuse POSIX qw\/strftime\/;<\/p>\n
\nmy $host = “192.168.1.101”;
\nmy $database = “powermonitor”;
\nmy $tablename = “data”;
\nmy $user = “powermonitor”;
\nmy $pw = [the password];<\/p>\n
\ndie(“Can’t open COM9: $^E\\n”);
\n}<\/p>\n
\nopen ($outfd, “>>”, “log.txt”) or die “Failed to open output file – $!n”;<\/p>\n
\n$|++;
\nselect($outfd);
\n$|++;
\nselect $output;<\/p>\n
\n$port->parity(‘none’);
\n$port->databits(8);
\n$port->stopbits(1);
\n$port->write_settings();
\n$port->are_match(“\\n”);<\/p>\n
\nmy $char = $port->lookfor();
\nif ($char) {
\n$char =~ s\/\\xd\/\/g;
\nif($char =~ m\/(\\d+),(\\d+),(\\d+)\/){
\nmy $dbh = DBI->connect(‘DBI:mysql:’.$database.’;host=’.$host, $user, $pw, { RaiseError => 1});
\nmy $thedate=strftime(‘%Y-%m-%d %H:%M:%S’,localtime);
\nmy $pvdate = strftime(‘%Y%m%d’,localtime);
\nmy $pvtime = strftime(‘%H:%M’,localtime);
\nmy $pvoutput = “get http:\/\/pvoutput.org\/service\/r2\/addoutput.jsp?key=[the api number]&sid=[the sid number]&d=$pvdate&pt=$pvtime&ip=$1”;<\/p>\n
\nor die “Can’t prepare SQL statement: $DBI::errstr\\n”;
\n$sth->execute
\nor die “Can’t execute SQL statement: $DBI::errstr\\n”;
\n$dbh->disconnect();
\n}
\nsleep (1);
\n}
\n}
\n$port->close();
\nexit(0);<\/p><\/blockquote>\n
\n—
\n— Database: `powermonitor`<\/p>\n
\n—
\nCREATE TABLE IF NOT EXISTS `data` (
\n`date` datetime NOT NULL,
\n`watts` int(11) NOT NULL,
\n`blinks` int(11) NOT NULL,
\n`vcc` int(11) NOT NULL,
\nPRIMARY KEY (`date`)
\n) ENGINE=InnoDB DEFAULT CHARSET=latin1;<\/p><\/blockquote>\n
\nuse warnings;
\nuse DBI;
\nuse LWP::Simple;
\nuse LWP::UserAgent;
\nuse HTTP::Request::Common qw(POST);<\/p>\n
\nmy $host = “192.168.1.101”;
\nmy $database = “powermonitor”;
\nmy $tablename = “data”;
\nmy $user = “powermonitor”;
\nmy $pw = “powermonitor”;<\/p>\n
\nmy $thetime_5=$thetime-300;
\nmy $thetimestring=strftime(‘%Y-%m-%d %H:%M:%S’,localtime($thetime));
\nmy $thetime_5string=strftime(‘%Y-%m-%d %H:%M:%S’,localtime($thetime_5));<\/p>\n
\nor die “Can’t prepare SQL statement: $DBI::errstr\\n”;
\n$sth->execute
\nor die “Can’t execute SQL statement: $DBI::errstr\\n”;
\nmy @result = $sth->fetchrow_array();
\nmy $pvdate= substr($result[0], 0, 4).substr($result[0],5,2).substr($result[0],8,2);
\nmy $pvwatth= $result[1];
\nmy $pvwatt= $result[2];
\nmy $pvtime= $result[3];
\nprint “$pvdate $pvwatth $pvwatt $pvtime\\n”;
\n$sth->finish();
\n$dbh->disconnect();<\/p>\n
\n$ua->default_header(‘X-Pvoutput-Apikey’=> “edaf9593007119df34f393acbd36703b7476457b”);
\n$ua->default_header(‘X-Pvoutput-SystemId’=> “12265”);<\/p>\n
\nd => $pvdate,
\nt => $pvtime,
\nv3=> $pvwatth,
\nv4=> $pvwatt
\n];<\/p>\n