291 lines
7.9 KiB
Arduino
291 lines
7.9 KiB
Arduino
#include <WiFi.h>
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#include <WebServer.h>
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#include <DHT.h>
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// ----------- WiFi -----------
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static const char* WIFI_SSID = "SSID";
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static const char* WIFI_PASS = "PASS";
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// ----------- DHT -----------
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static const int DHT_PIN = 10; // GPIO for DHT DATA
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static const int DHT_TYPE = DHT22; // DHT11 / DHT22 / DHT12?
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DHT dht(DHT_PIN, DHT_TYPE);
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// ----------- Server -----------
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WebServer server(80);
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// ----------- Reading interval -----------
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static const unsigned long READ_MS = 2000;
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unsigned long lastRead = 0;
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// ----------- Latest values -----------
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float latestH = NAN;
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float latestT_F = NAN;
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String htmlPage() {
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return R"HTML(
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<!doctype html>
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<html>
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<head>
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<meta charset="utf-8"/>
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<meta name="viewport" content="width=device-width,initial-scale=1"/>
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<title>ESP32 DHT</title>
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<style>
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body { font-family: system-ui, Arial; margin: 2rem; }
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.card { padding: 1rem 1.2rem; border: 1px solid #ddd; border-radius: 12px; max-width: 720px; }
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.val { font-size: 2rem; margin: 0.2rem 0; }
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.small { color: #555; font-size: 0.9rem; }
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.row { display: flex; gap: 2rem; flex-wrap: wrap; }
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.box { flex: 1; min-width: 240px; }
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canvas { width: 100%; height: 80%; background: #d3d3d3; border: 1px solid #eee; border-radius: 10px; }
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.legend { display: flex; gap: 1rem; align-items: center; margin-top: 0.5rem; }
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.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; margin-right: 0.35rem; }
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.btnbar { margin-top: 0.8rem; display: flex; gap: 0.6rem; flex-wrap: wrap; }
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button { padding: 0.5rem 0.8rem; border-radius: 10px; border: 1px solid #ddd; background: #fff; cursor: pointer; }
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</style>
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</head>
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<body>
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<div class="card">
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<h2>ESP32 DHT</h2>
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<div class="small">Updates every 2 seconds • Last ~43,200 Samples Max • ~24 Hours</div>
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<div class="row">
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<div class="box">
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<p><b>Temperature:</b></p>
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<p class="val" id="temp">--</p>
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</div>
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<div class="box">
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<p><b>Humidity:</b></p>
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<p class="val" id="hum">--</p>
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</div>
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</div>
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<canvas id="chart" width="800" height="600"></canvas>
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<div class="legend">
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<div><span class="dot" style="background:#e53935"></span>Temp (°F)</div>
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<div><span class="dot" style="background:#1e88e5"></span>Humidity (%)</div>
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</div>
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<div class="btnbar">
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<button onclick="clearData()">Clear chart</button>
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</div>
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</div>
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<script>
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const canvas = document.getElementById('chart');
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const ctx = canvas.getContext('2d');
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// Keep separate series; chart shares the x-axis (time)
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const MAX_POINTS = 43200;
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let tempSeries = []; // {x, v}
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let humSeries = []; // {x, v}
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function resizeForDPR() {
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const dpr = window.devicePixelRatio || 1;
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const rect = canvas.getBoundingClientRect();
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canvas.width = Math.round(rect.width * dpr);
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canvas.height = Math.round(rect.height * dpr);
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ctx.setTransform(dpr, 0, 0, dpr, 0, 0); // draw in CSS pixels
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}
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window.addEventListener('resize', resizeForDPR);
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resizeForDPR();
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function draw() {
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const w = canvas.getBoundingClientRect().width;
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const h = canvas.getBoundingClientRect().height;
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ctx.clearRect(0, 0, w, h);
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// Background grid
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ctx.fillStyle = '#fff';
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ctx.fillRect(0, 0, w, h);
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ctx.strokeStyle = '#eee';
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ctx.lineWidth = 1;
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const gridLines = 5;
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for (let i = 1; i < gridLines; i++) {
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const y = (h * i) / gridLines;
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ctx.beginPath();
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ctx.moveTo(0, y);
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ctx.lineTo(w, y);
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ctx.stroke();
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}
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// If no data, stop
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if (tempSeries.length === 0 && humSeries.length === 0) return;
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// Compute ranges (ignore missing nulls)
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const allTemp = tempSeries.map(p => p.v).filter(v => Number.isFinite(v));
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const allHum = humSeries.map(p => p.v).filter(v => Number.isFinite(v));
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const tempMin = allTemp.length ? Math.min(...allTemp) : 0;
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const tempMax = allTemp.length ? Math.max(...allTemp) : 1;
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const humMin = allHum.length ? Math.min(...allHum) : 0;
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const humMax = allHum.length ? Math.max(...allHum) : 1;
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// Avoid flat-line divisions
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const tempSpan = (tempMax - tempMin) || 1;
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const humSpan = (humMax - humMin) || 1;
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// x scale: index across MAX_POINTS window
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const count = Math.max(tempSeries.length, humSeries.length);
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const xForIndex = (i) => {
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if (count <= 1) return 0;
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return (w * i) / (count - 1);
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};
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function plot(series, color, min, span) {
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ctx.strokeStyle = color;
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ctx.lineWidth = 2;
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ctx.beginPath();
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for (let i = 0; i < series.length; i++) {
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const v = series[i].v;
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if (!Number.isFinite(v)) continue;
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const x = xForIndex(i);
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const y = h - ((v - min) / span) * (h - 20) - 10; // padding
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if (i === 0) ctx.moveTo(x, y);
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else ctx.lineTo(x, y);
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}
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ctx.stroke();
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}
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// Draw both series
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// (We scale each series to its own min/max so you always get a visible line.)
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plot(tempSeries, '#e53935', tempMin, tempSpan);
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plot(humSeries, '#1e88e5', humMin, humSpan);
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// Labels (min/max)
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ctx.fillStyle = '#333';
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ctx.font = '12px system-ui, Arial';
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ctx.fillText(`Temp range: ${tempMin.toFixed(1)}–${tempMax.toFixed(1)} °F`, 10, 16);
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ctx.fillText(`Hum range: ${humMin.toFixed(1)}–${humMax.toFixed(1)} %`, 10, 32);
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}
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function pushPoint(series, value) {
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if (Number.isFinite(value)) {
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series.push(value);
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while (series.length > MAX_POINTS) series.shift();
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} else {
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// Keep time alignment by pushing NaN placeholder only if you want strict alignment.
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// Here we just skip.
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}
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}
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function clearData() {
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tempSeries = [];
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humSeries = [];
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draw();
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}
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async function refresh() {
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try {
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const res = await fetch('/data?nocache=' + Date.now());
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const j = await res.json();
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// Update numbers
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if (j.t_f === null) document.getElementById('temp').textContent = '--';
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else document.getElementById('temp').textContent = j.t_f.toFixed(1) + ' °F';
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if (j.h === null) document.getElementById('hum').textContent = '--';
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else document.getElementById('hum').textContent = j.h.toFixed(1) + ' %';
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// Update series + chart
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if (j.t_f !== null) tempSeries.push({x: Date.now(), v: j.t_f});
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if (j.h !== null) humSeries.push({x: Date.now(), v: j.h});
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while (tempSeries.length > MAX_POINTS) tempSeries.shift();
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while (humSeries.length > MAX_POINTS) humSeries.shift();
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draw();
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} catch (e) {
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// ignore fetch errors
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}
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}
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refresh();
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setInterval(refresh, 2000);
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</script>
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</body>
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</html>
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)HTML";
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}
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void handleRoot() {
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server.send(200, "text/html", htmlPage());
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}
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void handleData() {
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// Convert NaN to null for easy JSON handling
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float h = latestH;
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float t = latestT_F;
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String json = "{";
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json += "\"h\": " + (isnan(h) ? String("null") : String(h, 1)) + ",";
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json += "\"t_f\": " + (isnan(t) ? String("null") : String(t, 1));
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json += "}";
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server.send(200, "application/json", json);
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}
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void setup() {
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Serial.begin(115200);
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delay(200);
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Serial.println("ESP32-C3 DHT11 starting...");
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dht.begin();
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WiFi.mode(WIFI_STA);
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WiFi.begin(WIFI_SSID, WIFI_PASS);
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Serial.print("Connecting to WiFi");
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while (WiFi.status() != WL_CONNECTED) {
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delay(300);
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Serial.print(".");
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}
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Serial.println();
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Serial.print("Connected. IP address: ");
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Serial.println(WiFi.localIP());
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server.on("/", handleRoot);
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server.on("/data", handleData);
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server.begin();
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Serial.println("HTTP server started.");
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}
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void loop() {
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// keep server responsive
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server.handleClient();
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unsigned long now = millis();
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if (now - lastRead < READ_MS) return;
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lastRead = now;
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float h = dht.readHumidity();
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float tC = dht.readTemperature(); // Celsius
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if (isnan(h) || isnan(tC)) {
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Serial.println("DHT read failed (check wiring/pull-up).");
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latestH = NAN;
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latestT_F = NAN;
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return;
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}
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latestH = h;
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latestT_F = dht.convertCtoF(tC);
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Serial.print("Humidity: ");
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Serial.print(latestH, 1);
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Serial.print(" %\tTemp: ");
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Serial.print(latestT_F, 1);
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Serial.println(" F");
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Serial.print("Connected. IP address: ");
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Serial.println(WiFi.localIP());
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}
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