用ESP8266(ESP-01)上傳溫濕度資料到ThingSpeak

之前有利用Arduino UNO + ESP8266 做過同樣的功能，但其實ESP8266是很強悍的晶片，能完全取代Arduino UNO的功能，小小的一片晶片不但體積縮小，也比較省電，接下來就看圖說故事，不多作解釋

<只需要esp01 就可以運作，不再需要Arduino的板子>

<USB to FTDI只是為了燒錄程式到ESP01, 燒錄成功後可以拆下來，記得燒錄時GPIO 0 必須接到GND>

<在Arduino IDE ，開發板記得選ESP8266，序列阜也要選FTDI的那個 port>

<都沒問題的話，從 ThingSpeak就可以看到上傳的資料>

Assembly List

Label	Part Type	Properties
DHT1	DHT11 Humitidy and Temperature Sensor
LED1	Red (633nm) LED	套件 1206 [SMD]; 顏色 Red (633nm)
R1	220Ω Resistor	接腳間隔 400 mil; 套件 THT; bands 4; tolerance ±5%; 電阻 220Ω
U1	ESP8266 WiFi Module	variant variant 1; part number ESP8266
元件1	FTDI Basic Programmer	類型 Basic; 電壓 5V

程式碼

#include "ESP8266WiFi.h"

#include <dht11.h>

dht11 DHT11;

#define LED 0 

const char* ssid = "ssid";

const char* password = "wifipassword";

const byte dataPin = 2;

const char* host = "api.thingspeak.com";

void setup() {

  // put your setup code here, to run once:

  pinMode(0,OUTPUT);

  Serial.begin(115200);

  

  WiFi.begin(ssid,password);

  

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

    

    delay(500);

    Serial.print(".");

  }

  digitalWrite(LED,HIGH);

  Serial.println("");

  Serial.println("WiFi connected");

  Serial.println(WiFi.localIP());

 

}

void loop() {

  int chk = DHT11.read(dataPin);

  

  // put your main code here, to run repeatedly:

  Serial.print("Connecting to  " );

  Serial.println(host);

  // usage WiFiClient

  WiFiClient client;

  const int httpPort = 80;

  if (!client.connect(host, httpPort)) {

    Serial.println("connection fialed");

    return;

  }

  client.print(String("GET /") + "update?api_key=thingspeakapikey=" + String(DHT11.temperature) + "&field2=" + String(DHT11.humidity) + "\r\n\r\n");

  Serial.println("溫度:"+String(DHT11.temperature)+" ===  "+"濕度: "+String(DHT11.humidity));

  

  

  delay(100);

  while (client.available()) {

    String line = client.readStringUntil('\r');

    Serial.print(line);

    for (int i=1 ; i<12; i++) {

      digitalWrite(LED,HIGH);

      delay(300);

      digitalWrite(LED,LOW);

      delay(300);

      digitalWrite(LED,HIGH);

    }

  }

  Serial.println();

  Serial.println("closing connection");

  delay(300000);

}