-#!/usr/bin/env python
+#!/usr/bin/env python3
import time
from bme280 import BME280
-from subprocess import PIPE, Popen
try:
from smbus2 import SMBus
except ImportError:
from smbus import SMBus
-print("""compensated-temperature.py - Use the CPU temperature to compensate temperature
-readings from the BME280 sensor. Method adapted from Initial State's Enviro pHAT
-review: https://medium.com/@InitialState/tutorial-review-enviro-phat-for-raspberry-pi-4cd6d8c63441
+import logging
+
+logging.basicConfig(
+ format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
+ level=logging.INFO,
+ datefmt='%Y-%m-%d %H:%M:%S')
+
+logging.info("""compensated-temperature.py - Use the CPU temperature
+to compensate temperature readings from the BME280 sensor.
+Method adapted from Initial State's Enviro pHAT review:
+https://medium.com/@InitialState/tutorial-review-enviro-phat-for-raspberry-pi-4cd6d8c63441
Press Ctrl+C to exit!
bus = SMBus(1)
bme280 = BME280(i2c_dev=bus)
+
# Get the temperature of the CPU for compensation
def get_cpu_temperature():
- process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)
- output, _error = process.communicate()
- return float(output[output.index('=') + 1:output.rindex("'")])
+ with open("/sys/class/thermal/thermal_zone0/temp", "r") as f:
+ temp = f.read()
+ temp = int(temp) / 1000.0
+ return temp
+
# Tuning factor for compensation. Decrease this number to adjust the
# temperature down, and increase to adjust up
-factor = 0.8
+factor = 2.25
-cpu_temps = [0] * 5
+cpu_temps = [get_cpu_temperature()] * 5
while True:
cpu_temp = get_cpu_temperature()
avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
raw_temp = bme280.get_temperature()
comp_temp = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
- print("Compensated temperature: {:05.2f} *C".format(comp_temp))
+ logging.info("Compensated temperature: {:05.2f} *C".format(comp_temp))
time.sleep(1.0)