Bye Bye Moore

猫マンション建築の野望を胸に零細事業主として資本主義の荒波に漕ぎ出したアラサー男の技術メモ

Arduino on ESP32 でMQTTの実験をしてみる その4:ESP32でsubmitする

shuzo-kino.hateblo.jp
では送信をやりました。
次は受信です。

実際のところ

動作環境

スクリプト

前回と同様、以下をベースにします。
pubsubclient/mqtt_esp8266.ino at master · knolleary/pubsubclient · GitHub
アスキーの"0"をおくると消灯、それ以外は点灯というロジックです。

#include <WiFi.h>
#include <PubSubClient.h>

// Update these with values suitable for your network.

const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASS";
const char* mqtt_server = "YOUR_ACCOUNT/IP";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '1') {
    digitalWrite(LED_BUILTIN, LOW); 
    Serial.println("coming here");
  } else {
    digitalWrite(LED_BUILTIN, HIGH); 
  }

}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      client.subscribe("msg/led");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}

動作ログ

初期接続に成功すると、mosquittoの方には、こんな感じで接続情報がきます

1507644406: New connection from YOUR_ACCOUNT/IP on port 1883.
1507644406: New client connected from ARDUINO_IP as ESP32Client-1f85 (c1, k15).

この状態からpublisherで以下のような感じで送ると……

$ mosquitto_pub -h YOUR_ACCOUNT/IP -t msg/comment -m 1 -q 1
$ mosquitto_pub -h YOUR_ACCOUNT/IP -t msg/comment -m 1 -q 1
$ mosquitto_pub -h YOUR_ACCOUNT/IP -t msg/comment -m 0 -q 1
$ mosquitto_pub -h YOUR_ACCOUNT/IP -t msg/comment -m 1 -q 1
...

Arduino側のシリアルにはこんな感じでログが出でて、
LEDの方もちゃんと突いたり消えたりしてくれます。

Connecting to YOURSSID
.....
WiFi connected
IP address: 
YOUR_ACCOUNT/IP
Attempting MQTT connection...connected
Message arrived [msg/led] 1
coming here
Message arrived [msg/led] 1
coming here
Message arrived [msg/led] 0
Message arrived [msg/led] 1
coming here
...