Question

我正在尝试将我的Feather Huzzah连接到本地MQTT服务器，但是该程序不断崩溃并抛出堆栈跟踪。当我尝试对堆栈跟踪进行解码时，它只是空的，更常见的是，我仅得到堆栈跟踪的一部分。这是我正在运行的代码，其中大多数与Arduino的发布/订阅客户端示例代码非常相似。我尝试擦除设备上的闪光灯，但似乎无济于事。

即使是陌生人，它也只能工作一次，但是一旦我再次尝试添加回调，代码就会停止工作并崩溃。如果我尝试删除回调，则没有任何变化。我尝试剥离很多代码只是为了查看是否可以与MQTT保持一致的连接，但这似乎也不起作用。 MQTT服务器是Ubuntu 18.04的最新Mosquitto。

#include <ESP8266WiFi.h>
#include <ArduinoJson.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <PubSubClient.h>

const char* ssid = "xxxxxxxx";
const char* password = "xxxxxxxxx";
const int hallPin = 14;
const int ledPin = 0;
const char* mqtt_server = "mosquitto.localdomain";
long lastMsg = 0;
char msg[100];
int value = 0;
int hallState = 0;

WiFiClient espClient;
PubSubClient client(espClient);
WiFiUDP ntpUDP;

// By default 'time.nist.gov' is used with 60 seconds update interval and
// no offset
NTPClient timeClient(ntpUDP);

// Setup and connect to the wifi
void setup_wifi() {
  delay(100);
  Serial.print("Connecting to: ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("Wifi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("Gateway: ");
  Serial.println(WiFi.gatewayIP());
}

//Reconnect to the MQTT broker
void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("/homeassistant/devices/doorbell", "hello world");
      // ... and resubscribe
      client.subscribe("/homeassistant/doorbell/receiver");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

//Process messages incoming from the broker
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]);
  }
}

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(hallPin, INPUT);
  Serial.begin(115200);
  setup_wifi();
  timeClient.begin();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    setup_wifi();
  }
  if (!client.connected()) {
    reconnect();
  }
  hallState = digitalRead(hallPin);
  if (hallState == LOW) {
    digitalWrite(ledPin, HIGH);
    generateAndSendMessage(); 
    delay(1000); //Add in a delay so it doesn't send messages extremely rapidly
  } else {
    digitalWrite(ledPin, LOW);
  }
}

void generateAndSendMessage() {
  timeClient.update();
  StaticJsonBuffer<100> jsonBuffer;
  JsonObject& root = jsonBuffer.createObject();
  root["sensor"] = "doorbell";
  root["time"] = timeClient.getEpochTime();
  root["value"] = 1;
  root.printTo(msg);
  Serial.println(msg);
  client.publish("/homeassistant/devices/doorbell", msg);
}

Answer 1

查看generateAndSendMessage函数，由于MQTT缓冲区的大小，我认为您遇到了问题。

MQTT缓冲区默认设置为128字节。这包括频道名称的长度以及消息。

您的频道长度为32个字节，用于发送消息的json缓冲区为100个字节长。因此，您可能刚刚超过了128字节标记。

只需在包含PubSubClient.h之前声明此内容即可。

#define MQTT_MAX_PACKET_SIZE  200

此宏将PubSubClient的缓冲区大小定义为200。您可以将其更改为您认为需要的任何值。

我希望这会有所帮助。

羽毛Huzzah MQTT

1 个答案: