TinkerNode NB-IoT 物联网开发板 测评第三弹 物联网初体验
在了解了NB板的基本功能后，我们现在来试试它的物联网功能吧。如果想了解前面的内容，请访问：
TinkerNode NB-IoT 物联网开发板 测评第二弹 功能全览
TinkerNode NB-IoT 物联网开发板 测评第一弹 开箱即用
本文假设你已经配置好NB板的相关开发环境，如果还没有请先看 第一弹
我们打开Arduino IDE在相应位置找到示例代码，这里要吐槽下，NB板的MQTT代码里面，
竟然没有自己的 IoT服务器https://iot.dfrobot.com.cn 相关的代码文件。
那我们只能选择这个，手工修改下代码。/*!
* @file Subscript_Topic.ino
*
* @brief Subscribe to a Topic. When the Topic receives the message,
* @brief it will execute a callback function to print out the message of the Topic.
*
* @copyright Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
* @licence The MIT License (MIT)
* @author (xiao.wu@dfrobot.com)
* @versionV1.0
* @date2019-02-20
* @get from https://www.dfrobot.com
*/
#include <WiFi.h>
#include <PubSubClient.h>
#include "DFRobot_Iot.h"
/*Set WIFI name and password*/
const char * WIFI_SSID = "WIFI_SSID";
const char * WIFI_PASSWORD = "WIFI_PASSWORD";
/*Configure device certificate information*/
String ProductID = "you_ProductID";
String DeviceId= "you_DeviceId";
String ApiKey = "you_ApiKey";
/*Configure the domain name and port number*/
String ONENET_SERVER = "mqtt.heclouds.com";
uint16_t PORT = 6002;
/*Set the Topic you need to subscribe to*/
const char * subTopic = "you_subscribe_Topic";
DFRobot_Iot myIot;
WiFiClient espClient;
PubSubClient client(espClient);
void connectWiFi(){
Serial.print("Connecting to ");
Serial.println(WIFI_SSID);
WiFi.begin(WIFI_SSID,WIFI_PASSWORD);
while(WiFi.status() != WL_CONNECTED){
delay(500);
Serial.print(".");
}
Serial.println();
Serial.println("WiFi connected");
Serial.print("IP Adderss: ");
Serial.println(WiFi.localIP());
}
void callback(char * topic, byte * payload, unsigned int len){
Serial.print("Recevice [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < len; i++){
Serial.print((char)payload);
}
Serial.println();
}
void ConnectCloud(){
while(!client.connected()){
Serial.print("Attempting MQTT connection...");
/*A device connected to the cloud platform based on an automatically calculated username and password*/
if(client.connect(myIot._clientId, myIot._username, myIot._password)){
Serial.println("connected");
client.subscribe(subTopic);
}else{
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void setup(){
Serial.begin(115200);
/*Connect to WIFI*/
connectWiFi();
/*Initialize the configuration of OneNet*/
myIot.init(ONENET_SERVER, ProductID, DeviceId, ApiKey);
client.setServer(myIot._mqttServer,PORT);
/*Set the callback function to execute the callback function when receiving the subscription information*/
client.setCallback(callback);
/*Connect to the cloud platform*/
ConnectCloud();
}
void loop(){
if(!client.connected()){
ConnectCloud();
}
client.loop();
}
相应的修改内容，请参考 DFROBOT的IoT服务器上相应的配置信息。因为还不能使用流量卡，我们这里用的是WIFI模式的物联。
现在让我们愉快地刷入，然后打开串口看看：
注意设置好波特率115200，然后我们在dfrobot的IoT web端输入信息：
已然正确连通了信息。接下来我们再修改下代码，通过IoT的Web端信息发送，点亮NB板上自带的小灯吧。
开始之前我们需要修改下 MQTT的 callback回调函数，你可参照我的代码进行覆盖。
void callback(char * topic, byte * payload, unsigned int len){
Serial.print("Recevice [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < len; i++){
Serial.print((char)payload);
}
Serial.println();
uint8_t LED_PIN = 2;
pinMode(LED_PIN, OUTPUT);
if((char)payload=='1'){
digitalWrite(LED_PIN, HIGH);
}
else if((char)payload=='0'){
digitalWrite(LED_PIN, LOW);
}
else{
Serial.println((char)payload);
}
}
完成后，我们重新刷入代码，BINGO，测试成功！
https://www.bilibili.com/video/BV1Qk4y197k1/
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