Ardunio + ESP8266 + thingspeak

serial.ino

void setup() {
  Serial1.begin(9600); //RX1 TX1，即 Pin18 及 Pin19
  Serial.begin(9600);
}
 
void loop() {
  if (Serial1.available()) {
    Serial.write(Serial1.read());
  }
 
  if (Serial.available()) {
    char chars = Serial.read();
    Serial1.write(chars);
  }
}

wifi.ino

#include <JeeLib.h>
#include "ESP8266.h"
ESP8266 wifi(Serial1);

// ThingSpeak Settings
char thingSpeakAddress[] = "api.thingspeak.com";
String writeAPIKey = "api key from thingspeak";
 // Time interval in milliseconds to update ThingSpeak (number of seconds * 1000 = interval)
const int updateThingSpeakInterval = 16 * 1000;
// Variable Setup
long lastConnectionTime = 0; 
boolean lastConnected = false;
int failedCounter = 0;
ISR(WDT_vect) { Sleepy::watchdogEvent(); }

void setup()
{
  // Start Serial for debugging on the Serial Monitor
  Serial.begin(9600);
  Serial.print("IP:");
  Serial.println( wifi.getLocalIP().c_str());   
}

void loop()
{
  if(millis() - lastConnectionTime < updateThingSpeakInterval)
  {
    Sleepy::loseSomeTime(1000);
    return;
  }
  
  uint8_t buffer[1024] = {0};
  // Read value from Analog Input Pin 0
  String analogValue0 = String(analogRead(A0), DEC);
  if (wifi.createTCP(thingSpeakAddress, 80)) {
      Serial.println("create tcp ok\r\n");
  } else {
      Serial.println("create tcp err\r\n");
      return;
  }
  String post = "POST /update HTTP/1.1 \r\nHost: api.thingspeak.com\r\nConnection: close\r\nX-THINGSPEAKAPIKEY: " +
  writeAPIKey + "\r\n" + 
  "Content-Type: application/x-www-form-urlencoded\r\n" +
  "Content-Length:" + (analogValue0.length() + 7) + "\r\n\r\n" + 
  "field1=" + analogValue0;
  Serial.println(post);
  wifi.send((const uint8_t*)post.c_str(), post.length());
  lastConnectionTime = millis();
  uint32_t len = wifi.recv(buffer, sizeof(buffer), 10000);
  if (len > 0) {
      Serial.println("Received:[");
      for(uint32_t i = 0; i < 15; i++) {
          Serial.print((char)buffer[i]);
      }
      Serial.println("]\r\n");
  }
  else {
    failedCounter++;
    Serial.println("Connection to ThingSpeak Failed ("+String(failedCounter, DEC)+")");   
  }
  if (wifi.releaseTCP()) {
      Serial.print("release tcp ok\r\n");
  } else {
      Serial.print("release tcp err\r\n");
  }
  # low energy mode
  wifi.deepSleep(updateThingSpeakInterval - 1000);
}