ESP32をWiFi経由でAWS IoTにMQTT接続

参考

AWSの設定はこれが一番わかりやすい

ハードも含めた流れが分かりやすいけど、内容少し古い？

できた

https://gyazo.com/a71ea9ad815ea8516e40827c351c19d3

スケッチ（低電圧版）

code:esp32_dht_sleep.c

// The MQTT topics that this device should publish/subscribe

// pin

DHT dht(DHTPIN, DHT11);

WiFiClientSecure net = WiFiClientSecure();

MQTTClient client = MQTTClient(256);

int computeDiscomfortIndex(float t, float h)

{

int index;

// 0.81T+0.01H(0.99T-14.3)+46.3

index = 0.81f * t + 0.01f * h * (0.99f * t - 14.3f) + 46.3f;

return index;

}

void publishMessage(float temperature, float humidity, int discomfort_index)

{

struct tm timeinfo;

if(!getLocalTime(&timeinfo)){

Serial.println("Failed to obtain time");

return;

}

sprintf(now, "%04d/%02d/%02d %02d:%02d:%02d",

timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday,

timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);

StaticJsonDocument<200> doc;

serializeJson(doc, jsonBuffer); // print to client

client.publish(AWS_IOT_PUBLISH_TOPIC, jsonBuffer);

}

void messageHandler(String &topic, String &payload) {

Serial.println("incoming: " + topic + " - " + payload);

// StaticJsonDocument<200> doc;

// deserializeJson(doc, payload);

}

void connectAWS()

{

WiFi.mode(WIFI_STA);

WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

Serial.println("Connecting to Wi-Fi");

while (WiFi.status() != WL_CONNECTED){

delay(500);

Serial.print(".");

}

Serial.println("");

// Configure WiFiClientSecure to use the AWS IoT device credentials

net.setCACert(AWS_CERT_CA);

net.setCertificate(AWS_CERT_CRT);

net.setPrivateKey(AWS_CERT_PRIVATE);

// Connect to the MQTT broker on the AWS endpoint we defined earlier

client.begin(AWS_IOT_ENDPOINT, 8883, net);

// Create a message handler

client.onMessage(messageHandler);

Serial.print("Connecting to AWS IOT");

while (!client.connect(THINGNAME)) {

Serial.print(".");

delay(100);

}

if(!client.connected()){

Serial.println("AWS IoT Timeout!");

return;

}

// Subscribe to a topic

client.subscribe(AWS_IOT_SUBSCRIBE_TOPIC);

Serial.println("");

Serial.println("AWS IoT Connected!");

}

void setup()

{

unsigned long starttime = millis();

uint64_t sleeptime;

Serial.begin(115200);

pinMode(LED, OUTPUT);

digitalWrite(LED, HIGH);

dht.begin();

connectAWS();

configTime(9 * 3600L, 0, "ntp.nict.jp", "time.google.com", "ntp.jst.mfeed.ad.jp");

sleeptime = 2000 - (millis() - starttime) / 1000;

delay(sleeptime);

//delay(2000); // Wait a few seconds between measurements.

float h = dht.readHumidity();

float t = dht.readTemperature();

// Check if any reads failed and exit early (to try again).

if (isnan(h) || isnan(t)) {

Serial.println("Failed to read from DHT sensor!");

return;

}

int di = computeDiscomfortIndex(t, h);

Serial.printf("Temp: %2.1f, ", t);

Serial.printf("Hum: %2.1f, ", h);

Serial.printf("DInd: %d", di);

Serial.println("");

publishMessage(t, h, di);

client.loop();

digitalWrite(LED, LOW);

delay(1000); // MQTTの送信を待つ

// Deep sleepする時間（マイクロ秒）を計算する

sleeptime = TIME_TO_SLEEP * 1000000 - (millis() - starttime) * 1000 - 1000000;

esp_deep_sleep(sleeptime); // DeepSleepモードに移行

// ここには戻らない

}

void loop()

{

}

code:secrets.h

const char WIFI_SSID[] = "<ssid>";

const char WIFI_PASSWORD[] = "<wifi-pw>";

const char AWS_IOT_ENDPOINT[] = "<aws-iot-endpoint>";

// Amazon Root CA 1

static const char AWS_CERT_CA[] PROGMEM = R"EOF(

-----BEGIN CERTIFICATE-----

-----END CERTIFICATE-----

)EOF";

// Device Certificate

static const char AWS_CERT_CRT[] PROGMEM = R"KEY(

-----BEGIN CERTIFICATE-----

-----END CERTIFICATE-----

)KEY";

// Device Private Key

static const char AWS_CERT_PRIVATE[] PROGMEM = R"KEY(

-----BEGIN RSA PRIVATE KEY-----

-----END RSA PRIVATE KEY-----

)KEY";