#include <SoftwareSerial.h>
SoftwareSerial mySerial(12, 11);

int readPin = 2;    //用来连接电位器

// The Led pin for debug
int ledPin = 13;
int light = 1;
int counter = 0;

// Use to check if the button is down
boolean buttonDown = false;

// battery related
int batteryPin = 0;
int batteryScale = 2;

// Connect to speaker
int tonePin = 5;

// For Cruise functions
int buttonPin = 1;  // 定义中断引脚为1，也就是D3引脚
boolean inCruiseMode = false; // 进入定速巡航模式
int cruisePower = 0;
int pressToUnlockFrom = 45; //在55和45（中点附近）再次按下，可以解除巡航
int pressToUnlockTo = 55;
int breakToUnlock = 25;  //或刹车到25以下，也可以解除巡航

void buttonStateChange () 
{
  buttonDown = digitalRead(3);
  if (buttonDown) {
    //tone(tonePin, 4000);
    mySerial.write((byte) 204);
  } else {
    //noTone(tonePin);
    mySerial.write((byte) 205);
  }
}

void stateChange()
{
  int readValue = readPowerValue();
  if (inCruiseMode) {
    if (readValue < pressToUnlockTo && readValue > pressToUnlockFrom) {
      inCruiseMode = false;
      cruisePower = 0;
    }
  } else {
    if (readValue > pressToUnlockTo) {
      inCruiseMode = true;
      cruisePower = readValue;
    }
  }
}

void setup()
{
  Serial.begin(9600); 
  mySerial.begin(9600);
  //attachInterrupt(buttonPin, stateChange, RISING);
  attachInterrupt(buttonPin, buttonStateChange, CHANGE); 
}

void switchLight()
{
  counter++;
  if (counter >= 12) counter = 0;
  else return;
  digitalWrite(ledPin, light);
  light = 1 - light;
}

int readPowerValue() {
  //读取电位器（传感器）的读数，值范围从0到1023
  int readValue = analogRead(readPin) / 10;
  if (readValue > 100) readValue = 100;
  return readValue;
}

void loop()
{  
  long t0 = millis();
  if (mySerial.available()) {
    while(mySerial.available()) {
      byte r = mySerial.read();
      //Serial.write(r);
    }
    //Serial.write("\r\n");
    digitalWrite(ledPin, light);
    light = 1 - light;
    counter = 0;
  }
  if (Serial.available()) {
    while(Serial.available()) {
      byte r = Serial.read();
      mySerial.write(r);
    }
  }
  //读取电位器（传感器）的读数，如果是巡航模式则保持速度
  int readValue = readPowerValue();
  if (inCruiseMode && readValue > breakToUnlock) {
    readValue = cruisePower;
  } else {
    inCruiseMode = false;
  }
  switchLight();
  mySerial.write((byte)readValue);
  //Serial.print(readValue);Serial.print("\r\n");
  double T = 100;
  int leftMs = (int) (t0 + T - millis());  
  delay(leftMs);
}