Simple MQTT monitoring script using BME280 and LTE

lte-mqtt-bme.py

from umqtt.simple import MQTTClient
from secrets import MQTT_SERVER, MQTT_USER, MQTT_PASS
import machine
import time
import ntptime
import gc
from breakout_bme280 import BreakoutBME280
from pimoroni_i2c import PimoroniI2C

PINS_BREAKOUT_GARDEN = {"sda": 4, "scl": 5}

i2c = PimoroniI2C(**PINS_BREAKOUT_GARDEN)
bme = BreakoutBME280(i2c)

reading = bme.read()
print(reading)
time.sleep(20)

log_file = open("log.txt", "a")

# Test reception e.g. with:
# mosquitto_sub -t foo_topic

import lte
import json
import ssl
MOBILE_APN = "iot.1nce.net"

# Slower clock to save some power
machine.freq(48000000)

con = lte.LTE(MOBILE_APN)
con.start_ppp()

print("PPP Connected")
ntptime.settime()
ltime = time.localtime()
log_file.write(f"{ltime[3]:02d}:{ltime[4]:02d} Starting\n")

try:
    while True:
        try:
            reading = bme.read()
            ltime = time.localtime()
            log_file.write(f"{ltime[3]:02d}:{ltime[4]:02d} Sending: {reading}...")

            c = MQTTClient(client_id="Clipper", server=MQTT_SERVER, user=MQTT_USER, password=MQTT_PASS, keepalive=30, ssl=ssl)
            c.connect()
            log_file.write(" connected...")
            c.publish(b"bme", json.dumps(reading))
            c.disconnect()
            log_file.write(" done.\n")
        except Exception as e:
            log_file.write(" failed.\n")
            log_file.write(f"Exception: {type(e)}: {e}\n")
            if isinstance(e, KeyboardInterrupt):
                raise
        log_file.flush()
        c = None
        gc.collect()
        #time.sleep(600)
        time.sleep(300)
finally:
    log_file.write("Disconnecting\n")
    log_file.close()
    print("Disconnecting...")
    con.stop_ppp()    
    print("Done!")