ESP32とDHT11で取得した温湿度をAWS IoT Coreへ送信してみた

import dht
from machine import Pin

sensor = dht.DHT11(Pin(27))
sensor.measure()

print(sensor.temperature())
print(sensor.humidity())

import network

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(WIFI_SSID, WIFI_PASSWORD)

WIFI_SSID = "<WIFI_SSID>"
WIFI_PASSWORD = "<WIFI_PASSWORD>"

AWS_IOT_ENDPOINT = "<AWS_IOT_ENDPOINT>"
THING_NAME = "dht11-esp32"
MQTT_TOPIC = "devices/dht11-esp32/telemetry"
MQTT_PORT = 8883

DHT_PIN = 27

AMAZON_ROOT_CA = "<AMAZON_ROOT_CA_PATH>"
DEVICE_CERTIFICATE = "<DEVICE_CERTIFICATE_PATH>"
PRIVATE_KEY = "<PRIVATE_KEY_PATH>"

import dht
import json
import network
import ntptime
import ssl
import time
from machine import Pin
from umqtt.simple import MQTTClient

from config import (
    AMAZON_ROOT_CA,
    AWS_IOT_ENDPOINT,
    DEVICE_CERTIFICATE,
    DHT_PIN,
    MQTT_PORT,
    MQTT_TOPIC,
    PRIVATE_KEY,
    THING_NAME,
    WIFI_PASSWORD,
    WIFI_SSID,
)

sensor = dht.DHT11(Pin(DHT_PIN))

def read_binary(path):
    with open(path, "rb") as file:
        return file.read()

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)

    if not wlan.isconnected():
        print("Connecting to Wi-Fi...")
        wlan.connect(WIFI_SSID, WIFI_PASSWORD)

        for _ in range(20):
            if wlan.isconnected():
                break
            time.sleep(1)

    if not wlan.isconnected():
        raise OSError("Wi-Fi connection timed out")

    print("Wi-Fi connected:", wlan.ifconfig()[0])

def sync_clock():
    try:
        ntptime.settime()
        print("Clock synchronized with NTP")
    except OSError as error:
        print("NTP synchronization failed:", error)

def connect_mqtt():
    client = MQTTClient(
        client_id=THING_NAME,
        server=AWS_IOT_ENDPOINT,
        port=MQTT_PORT,
        ssl=True,
        ssl_params={
            "key": PRIVATE_KEY,
            "cert": DEVICE_CERTIFICATE,
            "cadata": read_binary(AMAZON_ROOT_CA),
            "cert_reqs": ssl.CERT_REQUIRED,
            "server_hostname": AWS_IOT_ENDPOINT,
        },
    )
    client.connect()
    print("Connected to AWS IoT Core")
    return client

def read_telemetry():
    sensor.measure()
    return json.dumps(
        {
            "thing_name": THING_NAME,
            "temperature_c": sensor.temperature(),
            "humidity_percent": sensor.humidity(),
            "timestamp": time.time(),
        }
    )

def disconnect(client):
    if client is None:
        return

    try:
        client.disconnect()
    except OSError:
        pass

def main():
    connect_wifi()
    sync_clock()

    client = None

    while True:
        try:
            if client is None:
                client = connect_mqtt()

            message = read_telemetry()
            client.publish(MQTT_TOPIC, message)
            print("Published:", message)
        except OSError as error:
            print("DHT11, network, or MQTT error:", error)
            disconnect(client)
            client = None

        time.sleep(300)

if __name__ == "__main__":
    main()