https://blog.sorz.org/air/

graph.sh

#!/usr/bin/bash

DIR=/path/to/www/public
DATA=/path/to/pms5003.rrd

TIME=$1
time=$(date '+%H\:%M\:%S')

rrdtool graph $DIR/pm-$TIME.svg \
        --imgformat SVG \
        --start end-$TIME \
        --title "Particle Pollution Statistics - $TIME (µg/m³)" \
        DEF:pm10=$DATA:pm10:AVERAGE \
        DEF:pm25=$DATA:pm25:AVERAGE \
        DEF:pm100=$DATA:pm100:AVERAGE \
        LINE1:pm10#0084a4:"PM₁.₀" \
        LINE1:pm25#d85427:"PM₂.₅" \
        LINE1:pm100#676767:"PM₁₀" \
        VDEF:avg25=pm25,AVERAGE \
        VDEF:max25=pm25,MAXIMUM \
        VDEF:min25=pm25,MINIMUM \
        VDEF:now25=pm25,LAST \
        COMMENT:"        (updated on $time)" \
        GPRINT:avg25:"avg\: %2.0lf µg/m³" \
        GPRINT:max25:"max\: %2.0lf µg/m³" \
        GPRINT:min25:"min\: %2.0lf µg/m³" \
        GPRINT:now25:"cur\: %2.0lf µg/m³"

pms5003.py

#!/usr/bin/env python3
from subprocess import call
from struct import unpack
from serial import Serial


RRDTOOL = '/usr/bin/rrdtool'
RRDCACHE = '/tmp/rrdcached.sock'
DB_PATH = '/path/to/pms5003.rrd'
FORMAT = 'N:%d:%d:%d'

def read_once(ser):
    if ser.read() != b'\x42' or ser.read() != b'\x4d':
        return
    if ser.read(2) != b'\x00\x1c':
        return
    raw = ser.read(2 * 13 + 2)
    values = unpack('>HHHHHHHHHHHH', raw[:-4])
    checksum, = unpack('>H', raw[-2:])
    if checksum != sum(b'\x42\x4d\x1c' + raw[:-2]):
        return
    return values


def feed_to_rrdtool(values):
    args = FORMAT % values
    #code = call([RRDTOOL, 'update', '-d', RRDCACHE, DB_PATH, args])
    code = call([RRDTOOL, 'update', DB_PATH, args])
    if code != 0:
        print('rrdtool update failed')

def main():
    ser = Serial('/dev/ttyUSB0', 9600)

    while True:
        values = read_once(ser)
        if values is None:
            continue
        pms = values[:3]
        #print(pms)
        feed_to_rrdtool(pms)

if __name__ == '__main__':
    main()

rrd-create.sh

#!/bin/bash

rrdtool create pms5003.rrd \
        --step 1 \
        DS:pm10:GAUGE:10:0:1000 \
        DS:pm25:GAUGE:10:0:1000 \
        DS:pm100:GAUGE:10:0:1000 \
        RRA:AVERAGE:0.1:10:17280 \
        RRA:AVERAGE:0.5:60:43200 \
        RRA:AVERAGE:0.5:300:105120