【安信可BW16-Kit】MQTT点灯

dirty 发表于 2024-2-23 12:39

<div class='showpostmsg'><p>        本篇讲述在Arduino IDE环境通过MQTT实现远程控制板载LED.</p>

<p>一.原理了解及准备</p>

<p>        MQTT是一个基于客户端-服务器的消息发布/订阅传输协议。MQTT是基于发布/订阅范式的消息协议。MQTT应用需要服务器地址与端口，发布、订阅Topic、客户ID等。准备工作，在手机端下载安装“MQTT调试器”APP.</p>

<p>二.代码及工具准备</p>

<p>1.代码模板获取</p>

<p>        打开Arduino IDE，按如下菜单路径打开MQTT_Basic工程。</p>

<div style="text-align: center;"></div>

<div style="text-align: center;">图1:打开并创建工程</div>

<p>2.代码修改</p>

<p>(1)填入WIFI账号密码，这里自定义了发布、订阅Topic</p>

<pre>
<code>char ssid[] = "nova6_5G"; // your network SSID (name)
char pass[] = "12345678";// your network password
int status = WL_IDLE_STATUS;    // Indicator of Wifi status

char mqttServer[] = "test.mosquitto.org";
char clientId[]    = "amebaClient";
char publishTopic[] = "amebaClient/outTopic";
char publishPayload[] = "hello world";
char subscribeTopic[] = "amebaClient/inTopic";</code></pre>

<p>(2)在setup()添加led初始化</p>

<pre>
<code>void setup() {

// initialize digital pin's from all 3 colors as an output.
pinMode(LED_R, OUTPUT);
pinMode(LED_G, OUTPUT);
pinMode(LED_B, OUTPUT);

digitalWrite(LED_R, LOW);
digitalWrite(LED_G, LOW);
digitalWrite(LED_B, LOW);

//......
}</code></pre>

<p>(3)在连接函数reconnect去掉设备端发布</p>

<p>(4)在发布订阅回调函数添加应用代码.当设备端收到订阅消息，执行相应控制功能，并将接收消息发布出去</p>

<pre>
<code>void callback(char* topic, byte* payload, unsigned int length) {

char payload_r_on[]="LED_R_ON";
char payload_g_on[]="LED_G_ON";
char payload_b_on[]="LED_B_ON";
char payload_all_off[]="LED_OFF";

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

Serial.print("payload len:");
Serial.println(length);

if(strcmp(topic,subscribeTopic)==0)
{

   Serial.println("Receive subscribe.");
   if(memcmp((char *)payload,payload_r_on,strlen(payload_r_on))==0)
   {
      Serial.println("Light the Led Red");
      digitalWrite(LED_R, HIGH);
      digitalWrite(LED_G, LOW);
      digitalWrite(LED_B, LOW);
      client.publish(publishTopic,payload_r_on);
   }

   if(memcmp((char *)payload,payload_g_on,strlen(payload_g_on))==0)
   {
      Serial.println("Light the Led Green");
      digitalWrite(LED_R, LOW);
      digitalWrite(LED_G, HIGH);
      digitalWrite(LED_B, LOW);
      client.publish(publishTopic,payload_g_on);
   }

   if(memcmp((char *)payload,payload_b_on,strlen(payload_b_on))==0)
   {
      Serial.println("Light the Led Blue");
      digitalWrite(LED_R, LOW);
      digitalWrite(LED_G, LOW);
      digitalWrite(LED_B, HIGH);
      client.publish(publishTopic,payload_b_on);
   }

   if(memcmp((char *)payload,payload_all_off,strlen(payload_all_off))==0)
   {
      Serial.println("Light the Led Off");
      digitalWrite(LED_R, LOW);
      digitalWrite(LED_G, LOW);
      digitalWrite(LED_B, LOW);
      client.publish(publishTopic,payload_all_off);
   }

}

}</code></pre>

<p>3.“MQTT调试器”APP.设置</p>

<p>(1)test.mosquitto.org<a href="https://tool.lu/ip/" target="_blank">服务器IP查询</a>，可获得ip 91.121.93.94</p>

<p>(2)打开“MQTT调试器”APP，点“+”,在主机位置填写 tcp://91.121.93.94:1883 ，并保存。此时在app主界面已有添加的列表。</p>

<div style="text-align: center;"></div>

<div style="text-align: center;">图2:服务端输入配置</div>

<p>(3)点击列表进入，设置好订阅Topic： amebaClient/outTopic</p>

<p>(4)连接，设置发布如下图</p>

<div style="text-align: center;"></div>

<div style="text-align: center;">图3:MQTT发布</div>

<p>三.测验</p>

<p>    在APP上发布playload，可看到设备端收到后执行，手机端有收到订阅，串口日志</p>

<div style="text-align: center;"></div>

<div style="text-align: center;"> </div>

<div style="text-align: center;">图4:手机APP端收到订阅</div>

<div style="text-align: center;"></div>

<div style="text-align: center;">图5:串口日志</div>

<p>        至此，实现MQTT Client消息发布订阅功能，实现设备控制。</p>

<p> </p>

<p>        </p>

<p> </p>

<p>      </p>
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wangerxian 发表于 2024-2-23 17:21

<p>是不是物联网用MQTT协议的比较多？</p>

dirty 发表于 2024-2-23 21:09

wangerxian 发表于 2024-2-23 17:21
是不是物联网用MQTT协议的比较多？

<p>小数据量是的，负载读写数据</p>

wangerxian 发表于 2024-2-26 09:07

dirty 发表于 2024-2-23 21:09
小数据量是的，负载读写数据

<p>有机会我也去尝试一下，看看怎么样。</p>

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【安信可BW16-Kit】MQTT点灯