enviropi+ influx logger

log_influx.py

#!/usr/bin/env python3

import time
import datetime

from bme280 import BME280
from ltr559 import LTR559

from influxdb_client import InfluxDBClient, Point, WritePrecision
from influxdb_client.client.write_api import SYNCHRONOUS

try:
    from smbus2 import SMBus
except ImportError:
    from smbus import SMBus

# Corrects the relative humidity given a raw and corrected temperature reading
def correct_humidity(humidity, temperature, corr_temperature):
    dewpoint = temperature - ((100 - humidity) / 5)
    corr_humidity = 100 - (5 * (corr_temperature - dewpoint)) - 20
    return min(100, max(0, corr_humidity))


# Set up the BME280 weather sensor
bus = SMBus(1)
bme280 = BME280(i2c_dev=bus)
bme280.setup(mode="forced")
time.sleep(5)

# Set up the light sensor
ltr559 = LTR559()

# InfluxDB client to write to
token = "****"
org = "****"
bucket = "****"

while True:
  with InfluxDBClient(url="INFLUXDB_IP:8086", token=token, org=org) as client:
    write_api = client.write_api(write_options=SYNCHRONOUS)

    measurement = "indoors"
    location = "bedroom"

# Read temperature (read twice, as the first reading can be artificially high)
    temperature = bme280.get_temperature()
    time.sleep(1)
    temperature = bme280.get_temperature()

# Calculate corrected temperature
    offset = 7.5
    corr_temperature = temperature - offset
    w_temperature = measurement + ",location=" + location + " temperature=" + str(corr_temperature)

# Read humidity and correct it with the corrected temperature
    humidity = bme280.get_humidity()
    corr_humidity = correct_humidity(humidity, temperature, corr_temperature)
    w_humidity = measurement + ",location=" + location + " humidity=" + str(corr_humidity)

# Read pressure
    pressure = bme280.get_pressure()
    w_pressure = measurement + ",location=" + location + " pressure=" + str(pressure)

# Read light
    light = ltr559.get_lux()
    w_light = measurement + ",location=" + location + " lux=" + str(light)

# Log the data
    write_api.write(bucket, org, [w_temperature, w_humidity, w_pressure, w_light])

  client.close()
  time.sleep(15)