#include <DHT.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define DHTPIN 2 // DHT22数据引脚
#define DHTTYPE DHT22 // DHT22传感器类型
#define GAS_SENSOR_PIN A0 // MQ-2气体传感器输出引脚
#define BUZZER_PIN 3 // 蜂鸣器控制引脚
#define LED_PIN 4  // LED控制引脚
#define BUTTON_PIN 5 // 暂停按钮引脚

DHT dht(DHTPIN, DHTTYPE);
Adafruit_SSD1306 display(128, 32, &Wire, -1);

const float tempThreshold = 50.0; // 温度阈值
const float humidityThreshold = 70.0; // 湿度阈值
const int gasThreshold = 400; // 气体浓度阈值
bool alarmActive = false;
bool buttonState = false;

void setup() {
Serial.begin(9800);
dht.begin();
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
pinMode(BUZZER_PIN, OUTPUT);
pinMode(LED_PIN, OUTPUT);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop() {
float h = dht.readHumidity();
float t = dht.readTemperature();
int gasValue = analogRead(GAS_SENSOR_PIN);
buttonState = digitalRead(BUTTON_PIN);

if (isnan(h) || isnan(t) || gasValue == 0) {
Serial.println("Failed to read from sensors!");
return;
}

// 显示温湿度和气体浓度
display.clearDisplay();
display.setCursor(0, 0);
display.print("Temp: ");
display.print(t);
display.print(" C");
display.setCursor(0, 10);
display.print("Humidity: ");
display.print(h);
display.print(" %");
display.setCursor(0, 20);
display.print("Gas: ");
display.print(gasValue);
display.print(" ppm");
display.display();

// 检查温湿度是否超过阈值
if (t > tempThreshold || h > humidityThreshold) {
activateAlarm(true);
}

// 检查气体浓度是否超过阈值
if (gasValue > gasThreshold) {
activateAlarm(true);
}

// 如果按钮被按下，暂停警报
if (buttonState == LOW) {
alarmActive = false;
}

// 如果警报未激活，关闭声光报警
if (!alarmActive) {
digitalWrite(BUZZER_PIN, LOW);
digitalWrite(LED_PIN, LOW);
}
}

void activateAlarm(boolean activate) {
if (activate && !alarmActive) {
alarmActive = true;
digitalWrite(BUZZER_PIN, HIGH);
for (int i = 0; i < 8; i++) { // 自定义LED闪烁次数
digitalWrite(LED_PIN, HIGH);
delay(200);
digitalWrite(LED_PIN, LOW);
delay(200);
}
tone(BUZZER_PIN, 800); // 自定义报警音调持续800毫秒
delay(800);
noTone(BUZZER_PIN);