airquality.py

import RPi.GPIO as GPIO
import logging
import busio
import adafruit_sgp30
import board
import time
import sys

autoCalibrate = True
logging.basicConfig(
    format='%(asctime)s %(levelname)-8s %(message)s',
    level=logging.DEBUG,
    datefmt='%Y-%m-%d %H:%M:%S')

logging.info("Starting up...")

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(17, GPIO.OUT)

i2c_bus = busio.I2C(board.SCL, board.SDA)

sgp30 = adafruit_sgp30.Adafruit_SGP30(i2c_bus)

#sgp30.set_iaq_baseline(39649, 41175)

fan = None

if autoCalibrate:
  logging.info("Auto Calibrate")

  # CP
  logging.info("FAN ON")
  GPIO.output(17,GPIO.HIGH)
  fan = True

  for x in range(0,10):
      sgp30temp = adafruit_sgp30.Adafruit_SGP30(i2c_bus)

      for y in range(0,3):
          # CP
          eCO2, TVOC = sgp30temp.iaq_measure()
          baseline_eCO2, baseline_TVOC = sgp30temp.get_iaq_baseline()
          logging.info("Auto Calibrate: eCO2 = %d ppm \t TVOC = %d ppb \t baseline eCO2 = %d \t baseline TVOC = %d" % (eCO2, TVOC, baseline_eCO2, baseline_TVOC))
          time.sleep(15)

while True:
  eCO2, TVOC = sgp30.iaq_measure()
  baseline_eCO2, baseline_TVOC = sgp30.get_iaq_baseline()
  logging.info("eCO2 = %d ppm \t TVOC = %d ppb \t baseline eCO2 = %d \t baseline TVOC = %d" % (eCO2, TVOC, baseline_eCO2, baseline_TVOC))

  if TVOC > 900 and fan != True:
    logging.info("FAN ON")
    GPIO.output(17,GPIO.HIGH)
    fan = True

  if TVOC < 700 and fan != False:
    logging.info("FAN OFF")
    GPIO.output(17,GPIO.LOW)
    fan = False

  time.sleep(15)

airquality.service

[Unit]
Description=Air Quality Monitor
After=network-online.target
StartLimitInterval=200
StartLimitBurst=5

[Service]
Type=simple
Restart=always
RestartSec=30
User=pi
WorkingDirectory=/home/pi
ExecStart=/usr/bin/python3 /home/pi/airquality.py
StandardOutput=append:/var/log/airquality.log
StandardError=append:/var/log/airquality.log
SyslogIdentifier=airquality

[Install]
WantedBy=multi-user.target