station-meteo/code/main.py
2020-04-04 15:27:50 +02:00

168 lines
5.4 KiB
Python

"""
Station météo connectée vers MQTT via wifi.
A bit longer description.
Args:
variable (type): description
Returns:
type: description
Raises:
Exception: description
"""
import time
import machine
import network
import esp
import bme280_i2c
import adafruit_max31865
from ntptime import settime
from umqtt.robust import MQTTClient
import config
def WifiConnect(ssid, psk):
"""Connect to the wifi with given credentials."""
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
nets = wlan.scan()
for net in nets:
net_ssid = net[0].decode()
if net_ssid == ssid:
print('Network found!')
wlan.connect(net_ssid, psk)
while not wlan.isconnected():
machine.idle() # save power while waiting
print('WLAN connection succeeded!')
break
if not wlan.isconnected():
print("WLAN not found/not connected")
return wlan
def now(rtc):
"""Return a string representing date/time now."""
return "{0:04d}/{1:02d}/{2:02d}_{4:02d}:{5:02d}:{6:02d}".format(
*rtc.datetime()
)
def MqttPublish(client, topic, message, retain=False, qos=0, sleep=10):
"""MQTT publish helper."""
client.publish("test/{device}/{topic}".format(device=client.client_id,
topic=topic),
message,
retain=retain,
qos=qos)
time.sleep_ms(sleep)
# Connect to WLAN
wlan = WifiConnect(config.WIFI_SSID, config.WIFI_PSK)
# Create a micropython I2C object with the appropriate device pins
i2c = machine.I2C(scl=machine.Pin(5), sda=machine.Pin(4))
# Create a sensor object to represent the BME280
# Note that this will error if the device can't be reached over I2C.
bme = bme280_i2c.BME280_I2C(address=bme280_i2c.BME280_I2C_ADDR_SEC, i2c=i2c)
# Configure the sensor for the application in question.
bme.set_measurement_settings({
'filter': bme280_i2c.BME280_FILTER_COEFF_16,
'standby_time': bme280_i2c.BME280_STANDBY_TIME_500_US,
'osr_h': bme280_i2c.BME280_OVERSAMPLING_1X,
'osr_p': bme280_i2c.BME280_OVERSAMPLING_16X,
'osr_t': bme280_i2c.BME280_OVERSAMPLING_2X
})
# Start the sensor automatically sensing
bme.set_power_mode(bme280_i2c.BME280_NORMAL_MODE)
# Conversion coeff. between measured pressure and Seau Mean-level pressure
# Source: https://fr.wikipedia.org/wiki/Pression-altitude
SMLP_coef = pow(1.0-((0.0065*config.ALTITUDE)/288.15), 5.255)
# PT100 (via max81865 module) sensor setup
spi = machine.SPI(
-1,
sck=machine.Pin(14, machine.Pin.OUT),
mosi=machine.Pin(13, machine.Pin.OUT),
miso=machine.Pin(12, machine.Pin.OUT)
)
spi.init(baudrate=115200, polarity=0, phase=1)
max31865_cs = machine.Pin(2)
max31865 = adafruit_max31865.MAX31865(spi, max31865_cs)
# RTC setup
rtc = machine.RTC()
settime()
client = MQTTClient(client_id=config.CLIENT_ID,
server=config.MQTT_HOST,
user=config.MQTT_USERNAME,
password=config.MQTT_PASSWD,
port=config.MQTT_PORT)
client.DEBUG = True
client.connect()
MqttPublish(client, "last_boot", now(rtc), retain=True, qos=1)
MqttPublish(client, "location", config.LOCATION, retain=True, qos=1)
MqttPublish(client, "humidity/unit", "%", retain=True)
MqttPublish(client, "humidity/desc",
"Capteur Bosch BME280", retain=True, qos=0)
MqttPublish(client, "pressure/unit", "hPa", retain=True, qos=0)
MqttPublish(client, "pressure/desc",
"Capteur Bosch BME280", retain=True, qos=0)
MqttPublish(client, "pressure2/unit", "hPa", retain=True, qos=0)
MqttPublish(client, "pressure2/desc",
"Capteur Bosch BME280 revenu au niveau de la mer",
retain=True, qos=0)
MqttPublish(client, "temperature/unit", "degC", retain=True, qos=0)
MqttPublish(client, "temperature/desc",
"Capteur Bosch BME280", retain=True, qos=0)
MqttPublish(client, "temperature2/unit", "degC", retain=True, qos=0)
MqttPublish(client, "temperature2/desc",
"Sonde PT100/MAX31865", retain=True, qos=0)
MqttPublish(client, "wifi/ssid", config.WIFI_SSID, retain=True, qos=0)
MqttPublish(client, "wifi/ip", wlan.ifconfig()[0], retain=True, qos=1)
MqttPublish(client, "sys/esp8266_device_id",
"{:d}".format(esp.flash_id()),
retain=True, qos=1)
time.sleep_ms(1000)
# For each nature, a list describes:
# - mqtt topic
# - string format
# - factor (multiplier)
# - qos
topics = {"time": ["time/last_values", "{}", 1, 1],
"humidity": ["humidity/value", "{:.0f}", 1, 0],
"pressure": ["pressure/value", "{:.2f}", 0.01, 0],
"pressure2": ["pressure2/value", "{:.2f}", 0.01, 0],
"temperature": ["temperature/value", "{:.1f}", 1, 0],
"temperature2": ["temperature/value2", "{:.1f}", 1, 0],
"wifi_rssi": ["wifi/rssi", "{:.0f}", 1, 0],
}
while 1:
bme_data = bme.get_measurement()
bme_data['time'] = now(rtc)
bme_data['pressure2'] = bme_data['pressure']/SMLP_coef
bme_data['temperature2'] = max31865.temperature
bme_data['wifi_rssi'] = wlan.status('rssi')
print(bme_data)
for nature, param in topics.items():
MqttPublish(client,
param[0],
param[1].format(bme_data[nature]*param[2]),
qos=param[3],
sleep=20)
time.sleep(config.REFRESH_RATE)