test_bme.py

# mpremote run test_bme.py
import time
import sys

# from secrets import WIFI_SSID, WIFI_PASSWORD, MQTT_SERVER, MQTT_PORT, MQTT_USER, MQTT_PASSWORD
sys.path.append("/third-party")

from machine import Pin, I2C
from micropython_bmpxxx import bmpxxx

import config
from config import I2C_CONFIG

i2c_bus_info = I2C_CONFIG['bus']
i2c_bus = i2c_bus_info['bus_number']
i2c_sda = Pin(i2c_bus_info['sda_pin'])
i2c_scl = Pin(i2c_bus_info['scl_pin'])

# I2C sensors config - bme280

I2C_SENSORS = I2C_CONFIG.get('sensors', [])
I2C_SENSORS_FOUND = {}
bme_address = 0x77

for sensor in I2C_SENSORS:
    for s_type, s_params in sensor.items():
        if s_type == 'bme280':
            bme_address = s_params.setdefault('address', 0x77)

i2c = I2C(i2c_bus, sda=i2c_sda, scl=i2c_scl)
bme = bmpxxx.BME280(i2c, address=bme_address)

# https://forecast.weather.gov/data/obhistory/KFNL.html  1020.1
sea_level_pressure = bme.sea_level_pressure
print(f"Initial sea_level_pressure = {sea_level_pressure:.2f} hPa")

# reset driver to contain the accurate sea level pressure (SLP) from my nearest airport this hour
bme.sea_level_pressure = 1020.1
print(f"Adjusted sea level pressure = {bme.sea_level_pressure:.2f} hPa\n")

bme.pressure_oversample_rate = bme.OSR16
bme.temperature_oversample_rate = bme.OSR8
bme.iir_coefficient = bme.COEF_3

# Alternatively set known altitude in meters and the sea level pressure will be calculated
bme.altitude = 1512.0
print(f"Altitude 1512m = {bme.altitude:.2f} meters")
print(f"Adjusted SLP based on known altitude = {bme.sea_level_pressure:.2f} hPa\n")
pressure = bme.pressure
print(f"Sensor pressure = {pressure:.4f} hPa")

print("---- loop ----")
while True:
    # Pressure in hPA measured at sensor, temperature in Celsius
    # NOTE: only the BME280 supports %humidity and dew_point functionality
    pressure = bme.pressure
    print(f"sensor pressure = {pressure:.4f} hPa")
    temp = bme.temperature
    print(f"temp = {temp:.2f} C")
    humid = bme.humidity
    print(f"humidity = {humid:.2f}%")
    dew = bme.dew_point
    print(f"dew_point temperature = {dew:.2f} C")

    # Altitude in meters and in feet/inches
    meters = bme.altitude
    print(f"Altitude = {meters:.2f} meters\n")
    feet = meters * 3.28084
    feet_only = int(feet)
    inches = int((feet - feet_only) * 12)
#     print(f"Altitude = {feet_only} feet {inches} inches\n")

    time.sleep(2.0)