loop.pl

   1 #!/usr/bin/perl
   2 use strict;
   3
   4 use v5.10.1;
   5
   6 use Mojolicious::Lite;
   7 use Serial;
   8 use Mojo::IOLoop;
   9 use Mojo::IOLoop::Stream;
  10 use Mojo::Transaction::WebSocket;
  11 #use Mojo::JSON  qw(decode_json encode_json);
  12 use JSON;
  13 use Debug;
  14 use SMGLog;
  15 use Math::Round qw(nearest);
  16
  17 use constant pi => 3.14159265358979;
  18
  19 my $devname = "/dev/davis";
  20 my $datafn = ".loop_data";
  21 my $dataf;
  22
  23 my $poll_interval = 2.5;
  24 my $rain_mult = 0.2;                            # 0.1 or 0.2 mm or 0.01 inches
  25 my $tid;
  26 my $rid;
  27 our $did;
  28 my $nlcount;
  29 my $state = "ready";
  30 my $buf;
  31 my $dbg;
  32 my $ser;                                                        # the serial port Mojo::IOLoop::Stream
  33
  34 our $json = JSON->new->canonical(1);
  35
  36 our $ld = {};
  37
  38 our $loop_count;                                # how many LOOPs we have done, used as start indicator
  39
  40 our     @crc_table = (
  41                                   0x0, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
  42                                   0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
  43                                   0x1231, 0x210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
  44                                   0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
  45                                   0x2462, 0x3443, 0x420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
  46                                   0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
  47                                   0x3653, 0x2672, 0x1611, 0x630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
  48                                   0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
  49                                   0x48c4, 0x58e5, 0x6886, 0x78a7, 0x840, 0x1861, 0x2802, 0x3823,
  50                                   0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
  51                                   0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0xa50, 0x3a33, 0x2a12,
  52                                   0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
  53                                   0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0xc60, 0x1c41,
  54                                   0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
  55                                   0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0xe70,
  56                                   0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
  57                                   0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
  58                                   0x1080, 0xa1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
  59                                   0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
  60                                   0x2b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
  61                                   0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
  62                                   0x34e2, 0x24c3, 0x14a0, 0x481, 0x7466, 0x6447, 0x5424, 0x4405,
  63                                   0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
  64                                   0x26d3, 0x36f2, 0x691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
  65                                   0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
  66                                   0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x8e1, 0x3882, 0x28a3,
  67                                   0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
  68                                   0x4a75, 0x5a54, 0x6a37, 0x7a16, 0xaf1, 0x1ad0, 0x2ab3, 0x3a92,
  69                                   0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
  70                                   0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0xcc1,
  71                                   0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
  72                                   0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0xed1, 0x1ef0
  73                                  );
  74
  75 our %bar_trend;
  76
  77 $bar_trend{-60} = "Falling Rapidly";
  78 $bar_trend{196} = "Falling Rapidly";
  79 $bar_trend{-20} = "Falling Slowly";
  80 $bar_trend{236} = "Falling Slowly";
  81 $bar_trend{0} = "Steady";
  82 $bar_trend{20} = "Rising Slowly";
  83 $bar_trend{60} = "Rising Rapidly";
  84
  85 our $ending = 0;
  86
  87 $SIG{TERM} = $SIG{INT} = sub {++$ending; Mojo::IOLoop->stop;};
  88 $SIG{HUP} = 'IGNORE';
  89
  90
  91 get '/' => 'index';
  92
  93 # WebSocket weather service
  94 websocket '/index' => sub {
  95   my $c = shift;
  96
  97   # Opened
  98   $c->app->log->debug('WebSocket opened.');
  99   dbg 'WebSocket opened' if isdbg 'chan';
 100
 101   # Increase inactivity timeout for connection a bit
 102   $c->inactivity_timeout(300);
 103
 104   # Incoming message
 105   $c->on(
 106                  message => sub {
 107                          my ($c, $msg) = @_;
 108                          dbg "websocket: $msg" if isdbg 'chan';
 109                  },
 110                  json => sub {
 111                          my ($c, $msg) = @_;
 112                          dbg "websocket: $msg" if isdbg 'chan';
 113                  }
 114   );
 115
 116   # Closed
 117   $c->on(finish => sub {
 118     my ($c, $code, $reason) = @_;
 119     $c->app->log->debug("WebSocket closed with status $code.");
 120         dbg 'WebSocket closed with status $code' if isdbg 'chan';
 121   });
 122
 123   $c->render;
 124
 125 };
 126
 127 dbginit();
 128 if (@ARGV) {
 129         dbgadd(@ARGV);
 130 }
 131 dbgadd('chan');
 132
 133 dbg '***';
 134 dbg "*** starting $0";
 135 dbg '***';
 136
 137 our $dlog = SMGLog->new("day");
 138 dbg "before next tick";
 139 Mojo::IOLoop->next_tick(sub { loop() });
 140 dbg "before app start";
 141 app->start;
 142 dbg "after app start";
 143
 144 write_ld();
 145 close $dataf if $dataf;
 146
 147 dbg '***';
 148 dbg "*** ending $0";
 149 dbg '***';
 150
 151 exit 0;
 152
 153 ##################################################################################
 154
 155 sub loop
 156 {
 157
 158         open $dataf, "+>>", $datafn or die "cannot open $datafn $!";
 159         $dataf->autoflush(1);
 160
 161         read_ld();
 162
 163         dbg "last_min: " . scalar gmtime($ld->{last_min});
 164         dbg "last_hour: " . scalar gmtime($ld->{last_hour});
 165
 166         $did = Mojo::IOLoop->recurring(1 => sub {$dlog->flushall});
 167
 168         do_reopen($devname);
 169 }
 170
 171
 172
 173 sub on_read
 174 {
 175         my ($ser, $d) = @_;
 176         $buf .= $d;
 177         $d =~ s/([\%\x00-\x1f\x7f-\xff])/sprintf("%%%02X", ord($1))/eg;
 178         dbg "read added '$d' buf lth=" . length $buf if isdbg 'raw';
 179         if ($state eq 'waitnl' && $buf =~ /[\cJ\cM]+/) {
 180                 dbg "Got \\n" if isdbg 'state';
 181                 Mojo::IOLoop->remove($tid) if $tid;
 182                 undef $tid;
 183                 undef $buf;
 184                 $nlcount = 0;
 185                 $ser->write("LPS 1 1\n");
 186                 chgstate("waitloop");
 187         } elsif ($state eq "waitloop") {
 188                 if ($buf =~ /\x06/) {
 189                         dbg "Got ACK 0x06" if isdbg 'state';
 190                         chgstate('waitlooprec');
 191                         undef $buf;
 192                 }
 193         } elsif ($state eq 'waitlooprec') {
 194                 if (length $buf >= 99) {
 195                         dbg "got loop record" if isdbg 'chan';
 196                         chgstate('');
 197                         process($buf);
 198                         undef $buf;
 199                 }
 200         }
 201 }
 202
 203 sub start_loop
 204 {
 205         $nlcount = 1;
 206         dbg "start_loop writing $nlcount \\n" if isdbg 'state';
 207         $ser->write("\n");
 208         Mojo::IOLoop->remove($tid) if $tid;
 209         undef $tid;
 210         $tid = Mojo::IOLoop->recurring(0.6 => sub {
 211                                                                            if (++$nlcount > 10) {
 212                                                                                    dbg "\\n count > 10, closing connection" if isdbg 'chan';
 213                                                                                    do_reopen($devname);
 214                                                                                    return;
 215                                                                            }
 216                                                                            dbg "writing $nlcount \\n" if isdbg 'state';
 217                                                                            $ser->write("\n");
 218                                                                    });
 219         chgstate("waitnl");
 220 }
 221
 222 sub chgstate
 223 {
 224         dbg "state '$state' -> '$_[0]'" if isdbg 'state';
 225         $state = $_[0];
 226 }
 227
 228 sub do_reopen
 229 {
 230         my $name = shift;
 231         dbg "do reopen on '$name' ending $ending";
 232         unless ($ending) {
 233                 $ser = do_open($name);
 234                 start_loop();
 235                 chgstate('');
 236                 $nlcount = 0;
 237                 Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
 238         }
 239 }
 240
 241 sub do_open
 242 {
 243         my $name = shift;
 244
 245         $ser->close if $ser;
 246         undef $ser;
 247
 248         my $ob = Serial->new($name, 19200) || die "$name $!\n";
 249         dbg "streaming $name fileno(" . fileno($ob) . ")" if isdbg 'chan';
 250
 251         my $ser = Mojo::IOLoop::Stream->new($ob);
 252         $ser->on(error=>sub {dbg "serial $_[1]"; do_reopen($name) unless $ending});
 253         $ser->on(close=>sub {dbg "serial closing"; do_reopen($name) unless $ending});
 254         $ser->on(timeout=>sub {dbg "serial timeout";});
 255         $ser->on(read=>sub {on_read(@_)});
 256         $ser->start;
 257
 258         Mojo::IOLoop->remove($tid) if $tid;
 259         undef $tid;
 260         Mojo::IOLoop->remove($rid) if $rid;
 261         undef $rid;
 262         $rid = Mojo::IOLoop->recurring($poll_interval => sub {
 263                                                                            start_loop() if !$state;
 264                                                                    });
 265         chgstate('');
 266         $nlcount = 0;
 267
 268         return $ser;
 269 }
 270
 271 my @min;
 272 my @hour;
 273
 274 sub process
 275 {
 276         my $blk = shift;
 277         my $loo =  substr $blk,0,3;
 278         unless ( $loo eq 'LOO') {
 279                 dbg "Block invalid loo -> $loo" if isdbg 'chan'; return;
 280         }
 281
 282         my $tmp;
 283         my $temp;
 284         my $rain;
 285         my %h;
 286
 287         my $crc_calc = CRC_CCITT($blk);
 288
 289         if ($crc_calc==0) {
 290
 291                 # Common ones
 292                 $tmp = unpack("s", substr $blk,7,2) / 1000;
 293                 $h{Pressure} = nearest(1, in2mb($tmp));
 294
 295                 $tmp = unpack("s", substr $blk,9,2) / 10;
 296                 $h{Temp_In} = nearest(0.1, f2c($tmp));
 297
 298                 $temp  = nearest(0.1, f2c(unpack("s", substr $blk,12,2) / 10));
 299                 $h{Temp_Out}  = $temp;
 300
 301                 $tmp = unpack("C", substr $blk,14,1);
 302                 $h{Wind} = nearest(0.1, mph2mps($tmp));
 303                 $h{Dir}     = unpack("s", substr $blk,16,2)+0;
 304
 305                 my $wind = {w => $h{Wind}, d => $h{Dir}};
 306                 push @{$ld->{wind_min}}, $wind;
 307
 308                 $h{Humidity_Out} = unpack("C", substr $blk,33,1)+0;
 309                 $h{Humidity_In}  = unpack("C", substr $blk,11,1)+0;
 310
 311                 $tmp = unpack("C", substr $blk,43,1)+0;
 312                 $h{UV} = $tmp unless $tmp >= 255;
 313                 $tmp = unpack("s", substr $blk,44,2)+0; # watt/m**2
 314                 $h{Solar} = $tmp unless $tmp >= 32767;
 315
 316                 #       $h{Rain_Rate}  = nearest(0.1,unpack("s", substr $blk,41,2) * $rain_mult);
 317                 $rain = $h{Rain_Day}   = nearest(0.1, unpack("s", substr $blk,50,2) * $rain_mult);
 318                 my $delta_rain = $h{Rain} = nearest(0.1, ($rain >= $ld->{last_rain} ? $rain - $ld->{last_rain} : $rain)) if $loop_count;
 319                 $ld->{last_rain} = $rain;
 320
 321                 # what sort of packet is it?
 322                 my $sort =  unpack("C", substr $blk,4,1);
 323                 if ($sort) {
 324
 325                         # Newer LOOP2 packet
 326                         $tmp = unpack("C", substr $blk,18,2);
 327                         #               $h{Wind_Avg_10} = nearest(0.1,mph2mps($tmp/10));
 328                         $tmp = unpack("C", substr $blk,20,2);
 329                         #               $h{Wind_Avg_2} = nearest(0.1,mph2mps($tmp/10));
 330                         $tmp = unpack("C", substr $blk,22,2);
 331                         #               $h{Wind_Gust_10} = nearest(0.1,mph2mps($tmp/10));
 332
 333                         #               $h{Dir_Avg_10} = unpack("C", substr $blk,24,2)+0;
 334                         $tmp = unpack("C", substr $blk,30,2);
 335                         $h{Dew_Point} = nearest(0.1, f2c($tmp));
 336
 337                 } else {
 338
 339                         # Older LOOP packet
 340                         $tmp = unpack("C", substr $blk,15,1);
 341                         #               $h{Wind_Avg_10} = nearest(0.1,mph2mps($tmp));
 342                         $h{Dew_Point}  = nearest(0.1, dew_point($h{Temp_Out}, $h{Humidity_Out}));
 343                         $h{Rain_Month}  = nearest(0.1, unpack("s", substr $blk,52,2) * $rain_mult);
 344                         $h{Rain_Year}  = nearest(0.1, unpack("s", substr $blk,54,2) * $rain_mult);
 345                 }
 346
 347                 my $ts = time;
 348                 my $s;
 349                 my $dayno = int($ts/86400);
 350                 if ($dayno > $ld->{last_day}) {
 351                         $ld->{Temp_Out_Max} = $ld->{Temp_Out_Min} = $temp;
 352                         $ld->{last_day} = $dayno;
 353                 }
 354                 $ld->{Temp_Out_Max} = $temp if $temp > $ld->{Temp_Out_Max};
 355                 $ld->{Temp_Out_Min} = $temp if $temp < $ld->{Temp_Out_Min};
 356
 357                 if ($ts >= $ld->{last_hour} + 3600) {
 358                         $h{Pressure_Trend}    = unpack("C", substr $blk,3,1);
 359                         $h{Pressure_Trend_txt} = $bar_trend{$h{Pressure_Trend}};
 360                         $h{Batt_TX_OK}  = (unpack("C", substr $blk,86,1)+0) ^ 1;
 361                         $h{Batt_Console}  = nearest(0.01, unpack("s", substr $blk,87,2) * 0.005859375);
 362                         $h{Forecast_Icon}  = unpack("C", substr $blk,89,1);
 363                         $h{Forecast_Rule}  = unpack("C", substr $blk,90,1);
 364                         $h{Sunrise}  = sprintf( "%04d", unpack("S", substr $blk,91,2) );
 365                         $h{Sunrise}  =~ s/(\d{2})(\d{2})/$1:$2/;
 366                         $h{Sunset}   = sprintf( "%04d", unpack("S", substr $blk,93,2) );
 367                         $h{Sunset}  =~ s/(\d{2})(\d{2})/$1:$2/;
 368                         $h{Temp_Out_Max} = $ld->{Temp_Out_Max};
 369                         $h{Temp_Out_Min} = $ld->{Temp_Out_Min};
 370
 371                         if ($loop_count) {      # i.e not the first
 372                                 my $a = wind_average(scalar @{$ld->{wind_hour}} ? @{$ld->{wind_hour}} : {w => $h{Wind}, d => $h{Dir}});
 373
 374                                 $h{Wind_1h} = nearest(0.1, $a->{w});
 375                                 $h{Dir_1h} = nearest(0.1, $a->{d});
 376
 377                                 $a = wind_average(@{$ld->{wind_min}});
 378                                 $h{Wind_1m} = nearest(0.1, $a->{w});
 379                                 $h{Dir_1m} = nearest(1, $a->{d});
 380
 381                                 ($h{Rain_1m}, $h{Rain_1h}, $h{Rain_24h}) = calc_rain($rain);
 382                         }
 383                         $ld->{last_rain_min} = $ld->{last_rain_hour} = $rain;
 384
 385                         $s = genstr($ts, 'h', \%h);
 386
 387                         $ld->{last_hour} = int($ts/3600)*3600;
 388                         $ld->{last_min} = int($ts/60)*60;
 389                         @{$ld->{wind_hour}} = ();
 390                         @{$ld->{wind_min}} = ();
 391
 392                         write_ld();
 393
 394                 } elsif ($ts >= $ld->{last_min} + 60) {
 395                         my $a = wind_average(@{$ld->{wind_min}});
 396                         my %save;
 397
 398                         push @{$ld->{wind_hour}}, $a;
 399
 400                         if ($loop_count) {      # i.e not the first
 401                                 my $rm;
 402
 403                                 $h{Wind_1m} = nearest(0.1, $a->{w});
 404                                 $h{Dir_1m} = nearest(1, $a->{d});
 405                                 ($h{Rain_1m}, $h{Rain_1h}, $h{Rain_24h}) = calc_rain($rain);
 406                         }
 407                         $ld->{last_rain_min} = $rain;
 408
 409                         $h{Temp_Out_Max} = $ld->{Temp_Out_Max};
 410                         $h{Temp_Out_Min} = $ld->{Temp_Out_Min};
 411
 412                         $s = genstr($ts, 'm', \%h);
 413
 414                         $ld->{last_min} = int($ts/60)*60;
 415                         @{$ld->{wind_min}} = ();
 416
 417                         write_ld();
 418
 419                 } else {
 420                         my $o = gen_hash_diff($ld->{last_h}, \%h);
 421                         if ($o) {
 422                                 $s = genstr($ts, 'r', $o);
 423                         }
 424                         else {
 425                                 dbg "loop rec not changed" if isdbg 'chan';
 426                         }
 427                 }
 428                 output_str($s) if $s;
 429                 $ld->{last_h} = \%h;
 430                 ++$loop_count;
 431         } else {
 432                 dbg "CRC check failed for LOOP data!";
 433         }
 434         return;
 435 }
 436
 437 sub genstr
 438 {
 439         my $ts = shift;
 440         my $let = shift;
 441         my $h = shift;
 442
 443         my $j =  $json->encode($h);
 444         my ($sec,$min,$hr) = (gmtime $ts)[0,1,2];
 445         my $tm = sprintf "%02d:%02d:%02d", $hr, $min, $sec;
 446
 447         return qq|{"tm":"$tm","t":$ts,"$let":$j}|;
 448 }
 449
 450 sub output_str
 451 {
 452         my $s = shift;
 453         dbg $s;
 454 #       say $s;
 455         $dlog->writenow($s);
 456 }
 457
 458 sub gen_hash_diff
 459 {
 460         my $last = shift;
 461         my $now = shift;
 462         my %o;
 463         my $count;
 464
 465         while (my ($k, $v) = each %$now) {
 466                 if ($last->{$k} ne $now->{$k}) {
 467                         $o{$k} = $v;
 468                         ++$count;
 469                 }
 470         }
 471         return $count ? \%o : undef;
 472 }
 473
 474 sub dew_point
 475 {
 476         my $temp = shift @_;
 477         my $rh   = shift @_;
 478
 479         #  Using the simplified approximation for dew point
 480         #  Accurate to 1 degree C for humidities > 50 %
 481         #  http://en.wikipedia.org/wiki/Dew_point
 482
 483         my $dewpoint = $temp - ((100 - $rh) / 5);
 484
 485         # this is the more complete one (which doesn't work)
 486         #my $a = 6.1121;
 487         #my $b = 18.678;
 488         #my $c = 257.14;
 489         #my $ytrh = log(($rh/100) + ($b * $temp) / ($c + $temp));
 490         #my $dewpoint = ($c * $ytrh) / ($b - $ytrh);
 491
 492         return $dewpoint;
 493 }
 494
 495 sub CRC_CCITT
 496 {
 497     # Expects packed data...
 498     my $data_str = shift @_;
 499
 500         my $crc = 0;
 501         my @lst = split //, $data_str;
 502         foreach my $data (@lst) {
 503                 my $data = unpack("c",$data);
 504
 505                 my $crc_prev = $crc;
 506                 my $index = $crc >> 8 ^ $data;
 507                 my $lhs = $crc_table[$index];
 508                 #print "lhs=$lhs, crc=$crc\n";
 509                 my $rhs = ($crc << 8) & 0xFFFF;
 510                 $crc = $lhs ^ $rhs;
 511
 512
 513         }
 514
 515         return $crc;
 516 }
 517
 518 sub f2c
 519 {
 520         return ($_[0] - 32) * 5/9;
 521 }
 522
 523 sub mph2mps
 524 {
 525         return $_[0] * 0.44704;
 526 }
 527
 528 sub in2mb
 529 {
 530         return $_[0] * 33.8637526;
 531 }
 532
 533 sub wind_average
 534 {
 535         my ($sindir, $cosdir, $wind);
 536         my $count;
 537
 538         foreach my $r (@_) {
 539                 $wind += $r->{w};
 540                 $sindir += sin(d2r($r->{d})) * $r->{w};
 541                 $cosdir += cos(d2r($r->{d})) * $r->{w};
 542                 ++$count;
 543         }
 544
 545         my $avhdg = r2d(atan2($sindir, $cosdir));
 546         $avhdg += 360 if $avhdg < 0;
 547         return {w => nearest(0.1,$wind / $count), d => nearest(0.1,$avhdg)};
 548 }
 549
 550 # radians to degrees
 551 sub r2d
 552 {
 553     my $n = shift;
 554     return ($n / pi) * 180;
 555 }
 556
 557 # degrees to radians
 558 sub d2r
 559 {
 560     my $n = shift;
 561     return ($n / 180) * pi;
 562 }
 563
 564 sub calc_rain
 565 {
 566         my $rain = shift;
 567
 568         $ld->{rain24} ||= [];
 569
 570         my $Rain_1h = nearest(0.1, $rain >= $ld->{last_rain_hour} ? $rain - $ld->{last_rain_hour} : $rain); # this is the rate for this hour, so far
 571         my $rm = nearest(0.1, $rain >= $ld->{last_rain_min} ? $rain - $ld->{last_rain_min} : $rain);
 572         my $Rain_1m = nearest(0.1, $rm);
 573         push @{$ld->{rain24}}, $Rain_1m;
 574         $ld->{rain_24} += $rm;
 575         while (@{$ld->{rain24}} > 24*60) {
 576                 $ld->{rain_24} -= shift @{$ld->{rain24}};
 577         }
 578         my $Rain_24h = nearest(0.1, $ld->{rain_24});
 579         return ($Rain_1m, $Rain_1h, $Rain_24h);
 580 }
 581
 582 sub read_ld
 583 {
 584         return unless $dataf;
 585
 586         seek $dataf, 0, 0;
 587         my $s = <$dataf>;
 588         chomp $s;
 589         dbg "read loop data: $s" if isdbg 'json';
 590         $ld = $json->decode($s) if length $s;
 591
 592         # sort out rain stats
 593         my $c;
 594         if (($c = @{$ld->{rain24}}) < 24*60) {
 595                 my $diff = 24*60 - $c;
 596                 unshift @{$ld->{rain24}}, 0 for 0 .. $diff;
 597         }
 598         my $rain;
 599         $rain += $_ for @{$ld->{rain24}};
 600         $ld->{rain_24} = nearest(0.1, $rain);
 601         delete $ld->{hour};
 602         delete $ld->{min};
 603 }
 604
 605 sub write_ld
 606 {
 607         return unless $dataf;
 608
 609         seek $dataf, 0, 0;
 610         truncate $dataf, 0;
 611         $ld->{ts} = time;
 612         my $s = $json->encode($ld);
 613         dbg "write loop data: $s" if isdbg 'json';
 614         print $dataf "$s\n";
 615 }
 616
 617
 618 __DATA__
 619
 620 @@ index.html.ep
 621 <!DOCTYPE html>
 622 <html>
 623   <head><title>DWeather</title></head>
 624   <body>
 625     <script>
 626       var ws;
 627       if ("WebSocket" in window) {
 628         ws = new WebSocket('<%= url_for('index')->to_abs %>');
 629                 //ws = new WebSocket();
 630       }
 631       if(typeof(ws) !== 'undefined') {
 632         ws.onmessage = function (event) {
 633           document.body.innerHTML += JSON.parse(event.data).test;
 634         };
 635         ws.onopen = function (event) {
 636           ws.send(JSON.stringify({weather: 'WebSocket support works! ♥'}));
 637         };
 638       }
 639       else {
 640         document.body.innerHTML += 'Browser does not support WebSockets.';
 641       }
 642
 643       var ws = new WebSocket('<%= url_for('weather')->to_abs %>');
 644
 645       // Incoming messages
 646       ws.onmessage = function(event) {
 647         document.body.innerHTML += event.data + '<br/>';
 648       };
 649
 650     </script>
 651         <h1>DWeather</h1>
 652
 653   </body>
 654 </html>