BitBar plugin for air quality

aq.5m.php

#!/usr/bin/env php
<?php
error_reporting( 0 );

// This version is for SwiftBar. swiftbar.app

// <bitbar.title>EPA Air Quality</bitbar.title>
// <bitbar.version>v2.0</bitbar.version>
// <bitbar.author>Jason Snell</bitbar.author>
// <bitbar.author.github>jasonsnell</bitbar.author.github>
// <bitbar.desc>Displays PurpleAir data from a nearby station.</bitbar.desc>
// <swiftbar.hideRunInTerminal>true</swiftbar.hideRunInTerminal>
// <swiftbar.hideDisablePlugin>true</swiftbar.hideDisablePlugin>
// <swiftbar.hideSwiftBar>true</swiftbar.hideSwiftBar>

// This version uses the "US EPA" adjustment for wood smoke
// since my version is really meant to be when there are fires.
// Info here: <https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=540979&Lab=CEMM>
// jsnell@intertext.com


// Put your nearest PurpleAir sensor ID here

$show = '4896';

$url = ( 'https://www.purpleair.com/json?show=' . $show );

// Get the sensor data via JSON
$json  = @file_get_contents( $url );
$array = json_decode( $json, true );
for ( $i = 0; $i < sizeof( $array['results'] ); $i++ ) {
	$array['results'][ $i ]['Stats'] = json_decode( $array['results'][ $i ]['Stats'], true );
}
$pm25a    = $array['results'][0]['pm2_5_cf_1'];
$pm25b    = $array['results'][1]['pm2_5_cf_1'];
$humidity = $array['results'][0]['humidity']; 
$location = $array['results'][0]['Label'];
$lat      = $array['results'][1]['Lat'];
$lon      = $array['results'][1]['Lon'];
$sensor1  = $array['results'][0]['Stats']['v2'];
$sensor1l = $array['results'][0]['Stats']['v'];
$asensor  = $array['results'][0]['Stats']['v1'];
$bsensor  = $array['results'][1]['Stats']['v1'];


$epaPM    = ( (0.52 * ( ($pm25a + $pm25b) / 2) - (.085 * $humidity) + 5.71) );

$AQI      = aqiFromPM( $epaPM );

$aAQI     = aqiFromPM( $asensor );
$bAQI     = aqiFromPM( $bsensor );

settype( $AQI, 'integer' );
settype( $aAQI, 'integer' );
settype( $bAQI, 'integer' );

echo getAQISymbol($AQI) . ' ' . $AQI . getAQItrend( $sensor1, $sensor1l )  . '
---
' . getAQIDescription( $AQI ) . ' (' . $AQI . ')|color=' . getAQIcolor( $AQI ) . '
' . $location . '|href=https://www.purpleair.com/map?opt=1/i/mAQI/a10/cC5&select=' . $show . '#11/' . $lat . '/' . $lon ;


// Function to get AQI number from PPM reading
function aqiFromPM( $pm ) {
	if ( is_nan( $pm ) ) {
		return '-';
	}
	if ( isset( $pm ) == false ) {
		return 'Error: No value';
	}
	if ( $pm < 0.0 ) {
		return $pm;
	}
	if ( $pm > 1000.0 ) {
		return '-';
	}
	if ( $pm > 350.5 ) {
		return calcAQI( $pm, 500.0, 401.0, 500.0, 350.5 );
	} elseif ( $pm > 250.5 ) {
		return calcAQI( $pm, 400.0, 301.0, 350.4, 250.5 );
	} elseif ( $pm > 150.5 ) {
		return calcAQI( $pm, 300.0, 201.0, 250.4, 150.5 );
	} elseif ( $pm > 55.5 ) {
		return calcAQI( $pm, 200.0, 151.0, 150.4, 55.5 );
	} elseif ( $pm > 35.5 ) {
		return calcAQI( $pm, 150.0, 101.0, 55.4, 35.5 );
	} elseif ( $pm > 12.1 ) {
		return calcAQI( $pm, 100.0, 51.0, 35.4, 12.1 );
	} elseif ( $pm >= 0.0 ) {
		return calcAQI( $pm, 50.0, 0.0, 12.0, 0.0 );
	} else {
		return '-';
	}
}

// Function that actually calculates the AQI number
function calcAQI( $Cp, $Ih, $Il, $BPh, $BPl ) {
	$a = ( $Ih - $Il );
	$b = ( $BPh - $BPl );
	$c = ( $Cp - $BPl );
	return round( ( $a / $b ) * $c + $Il );
}

// Function that gets the AQI's description
function getAQIDescription( $aqinum ) {
	if ( $aqinum >= 401 ) {
		return 'Hazardous';
	} elseif ( $aqinum >= 301 ) {
		return 'Hazardous';
	} elseif ( $aqinum >= 201 ) {
		return 'Very Unhealthy';
	} elseif ( $aqinum >= 151 ) {
		return 'Unhealthy';
	} elseif ( $aqinum >= 101 ) {
		return 'Unhealthy SG';
	} elseif ( $aqinum >= 51 ) {
		return 'Moderate';
	} elseif ( $aqinum >= 0 ) {
		return 'Good';
	} else {
		return 'Unknown';
	}
}


// Function that gets the AQI's SF Symbol
function getAQISymbol( $aqinum ) {
	if ( $aqinum >= 201 ) {
		return ':smoke.fill: ';
	} elseif ( $aqinum >= 151 ) {
		return ':aqi.high: ';
	} elseif ( $aqinum >= 101 ) {
		return ':aqi.medium: ';
	} elseif ( $aqinum >= 51 ) {
		return ':aqi.medium: ';
	} elseif ( $aqinum >= 0 ) {
		return ':aqi.low: ';
	} else {
		return 'Unknown';
	}
}


// Function that gets the AQI's color code
function getAQIColor( $aqinum ) {

	if ( $aqinum >= 301 ) {
		return '#7e0023';
	} elseif ( $aqinum >= 201 ) {
		return '#8f3f97';
	} elseif ( $aqinum >= 151 ) {
		return '#ff0000';
	} elseif ( $aqinum >= 101 ) {
		return '#cf7332,Orange';
	} elseif ( $aqinum >= 51 ) {
		return '#333333,#ffff00';
	} elseif ( $aqinum >= 0 ) {
		return '#0c990c,#00e400';
	} else {
		return '#000000,#ffffff';
	}
}

// Function that checks for the AQI trend
function getAQItrend( $average, $live ) {
	if ( ( $average - $live ) > 6 ) {
		return ' :arrowtriangle.down.fill:';
	} elseif ( ( $average - $live ) < -6 ) {
		return ' :arrowtriangle.up.fill:';
	} else {
		return '';
	}
}

?>

Thank you for saving me a bunch of time by not having to write this myself, exactly what I wanted!

Saw the article you wrote about this and I decided to try it. It works nicely! Thank you

New version integrates new draft EPA adjustment to make purpleair sensors more accurate with wood smoke.

new version tweaks EPA adjustment because it wasn't quite right!