X-Git-Url: https://zdv2.bktei.com/gitweb/EVA-2020-02-2.git/blobdiff_plain/e2d010e2ae9761418d5a59f79cc4b60a251665d5..c8bf56890d0e7b6e7e1993e164f14d55d72f9544:/examples/compensated-temperature.py?ds=sidebyside diff --git a/examples/compensated-temperature.py b/examples/compensated-temperature.py index 3679610..b648f57 100755 --- a/examples/compensated-temperature.py +++ b/examples/compensated-temperature.py @@ -1,15 +1,21 @@ -#!/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 +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 @@ -24,16 +30,17 @@ bme280 = BME280(i2c_dev=bus) # Get the temperature of the CPU for compensation def get_cpu_temperature(): - process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True) - 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() @@ -42,5 +49,5 @@ while True: 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)