综合实战:智能环境监测站

这个项目用到了哪些知识

系统接线图

整合状态机

完整代码

下面是可直接编译上传的完整工程(ESP32,需装 U8g2、DHT sensor library)。填入你的 WiFi 后即可运行:

#include <WiFi.h>
#include <HTTPClient.h>
#include <U8g2lib.h>
#include <DHT.h>

// ---------- 引脚与配置 ----------
#define DHTPIN    4
#define DHTTYPE   DHT11
const int btnPin = 5;
const int ledPin = 2;
const float TEMP_ALARM = 30.0;   // 温度报警阈值 ℃

const char* ssid = "你的WiFi名";
const char* pass = "你的WiFi密码";

// ---------- 对象 ----------
DHT dht(DHTPIN, DHTTYPE);
U8G2_SSD1306_128X64_NONAME_1_HW_I2C u8g2(U8G2_R0);

// ---------- 全局状态 ----------
float temp = 0, humi = 0;
float tMax = -99, tMin = 99;
int page = 0;                 // 0=实时页 1=统计页
bool alarm = false;

// 三组非阻塞定时器
unsigned long tSensor = 0, tDisp = 0, tUpload = 0;
unsigned long lastBtn = 0;
bool lastBtnState = HIGH;

// ---------- 功能函数 ----------
void readSensor() {
  float t = dht.readTemperature();
  float h = dht.readHumidity();
  if (isnan(t) || isnan(h)) return;   // 读失败就跳过
  temp = t; humi = h;
  if (t > tMax) tMax = t;             // 更新统计
  if (t < tMin) tMin = t;
  alarm = (t >= TEMP_ALARM);           // 判阈值
  digitalWrite(ledPin, alarm ? HIGH : LOW);
}

void updateDisplay() {
  u8g2.firstPage();
  do {
    u8g2.setFont(u8g2_font_ncenB08_tr);
    if (page == 0) {                  // ---- 实时页 ----
      u8g2.drawStr(0, 12, "== Live ==");
      char buf[24];
      sprintf(buf, "Temp: %.1f C", temp);
      u8g2.drawStr(0, 32, buf);
      sprintf(buf, "Humi: %.0f %%", humi);
      u8g2.drawStr(0, 48, buf);
      if (alarm) u8g2.drawStr(0, 63, "! ALARM !");
    } else {                          // ---- 统计页 ----
      u8g2.drawStr(0, 12, "== Stats ==");
      char buf[24];
      sprintf(buf, "Max: %.1f C", tMax);
      u8g2.drawStr(0, 32, buf);
      sprintf(buf, "Min: %.1f C", tMin);
      u8g2.drawStr(0, 48, buf);
    }
  } while (u8g2.nextPage());
}

void uploadData() {
  if (WiFi.status() != WL_CONNECTED) return;
  HTTPClient http;
  http.begin("http://example.com/api/data");
  http.addHeader("Content-Type", "application/json");
  String body = "{\"temp\":" + String(temp) +
                ",\"humi\":" + String(humi) + "}";
  http.POST(body);
  http.end();
}

void handleButton() {
  bool s = digitalRead(btnPin);
  // 下降沿 + 50ms 消抖 → 切换页面
  if (lastBtnState == HIGH && s == LOW && millis() - lastBtn > 50) {
    page = 1 - page;              // 0↔1 翻转
    lastBtn = millis();
  }
  lastBtnState = s;
}

// ---------- 初始化 ----------
void setup() {
  pinMode(btnPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
  dht.begin();
  u8g2.begin();

  WiFi.begin(ssid, pass);       // 后台连,不阻塞主流程太久
}

// ---------- 主循环:纯调度,无 delay ----------
void loop() {
  unsigned long now = millis();

  if (now - tSensor >= 2000)  { tSensor = now; readSensor(); }
  if (now - tDisp   >= 200)   { tDisp   = now; updateDisplay(); }
  if (now - tUpload >= 30000) { tUpload = now; uploadData(); }
  handleButton();   // 每轮都查,按键最灵敏
}

从这里继续:进阶路线