Smart AC Controller

#include <Arduino.h>
#include <WiFi.h>
#include <WebServer.h>
#include <Preferences.h>
#include <SPI.h>
#include <DHT.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <XPT2046_Touchscreen.h>
#include <IRremoteESP8266.h>
#include <IRrecv.h>
#include <IRsend.h>
#include <IRutils.h>

// Change these two strings, then reboot, to join your home Wi-Fi.

// Forward declarations
bool slotExists(const String &slot);
String safeSlot(String slot);
void saveRaw(const String &slot, uint16_t *raw, uint16_t length);
bool sendSlot(String slot);
void startLearning(String slot);
void drawButton(int16_t x, int16_t y, int16_t w, int16_t h, const char *label, uint16_t color);
void drawScreen();
void handleTouch();
String htmlPage();
void setupWeb();
void connectWiFi();
void checkLearning();

const char *WIFI_SSID = "";
const char *WIFI_PASSWORD = "";
const char *SETUP_AP_NAME = "AC-Controller-Setup";
const char *SETUP_AP_PASSWORD = "configureme";

static const uint8_t TFT_CS_PIN = 4;
static const uint8_t TFT_DC_PIN = 27;
static const uint8_t TFT_RST_PIN = 26;
static const uint8_t TOUCH_CS_PIN = 25;
static const uint8_t SPI_SCK_PIN = 18;
static const uint8_t SPI_MISO_PIN = 19;
static const uint8_t SPI_MOSI_PIN = 23;
static const uint8_t IR_RECEIVE_PIN = 13;
static const uint8_t IR_SEND_PIN = 32;
static const uint8_t DHT_PIN = 33;

static const uint16_t SCREEN_W = 320;
static const uint16_t SCREEN_H = 240;
static const uint16_t IR_BUFFER_SIZE = 1024;
static const uint32_t LEARN_WINDOW_MS = 12000;
static const uint8_t IR_KHZ = 38;

Adafruit_ILI9341 tft(TFT_CS_PIN, TFT_DC_PIN, TFT_RST_PIN);
XPT2046_Touchscreen touch(TOUCH_CS_PIN);
DHT dht(DHT_PIN, DHT22);
IRrecv irrecv(IR_RECEIVE_PIN, IR_BUFFER_SIZE, 15, true);
IRsend irsend(IR_SEND_PIN);
decode_results results;
WebServer server(80);
Preferences preferences;

String learningSlot;
uint32_t learnStartedAt = 0;
String statusText = "Ready - learn a remote button first";
float roomTemp = NAN;
float roomHumidity = NAN;
uint32_t lastDhtRead = 0;
uint32_t lastScreenDraw = 0;
bool screenDirty = true;

const char *slots[] = {"power", "minus", "plus", "fan", "swing", "sleep", "mode", "last"};
const uint8_t SLOT_COUNT = sizeof(slots) / sizeof(slots[0]);

bool slotExists(const String &slot) {
  for (uint8_t i = 0; i < SLOT_COUNT; i++) if (slot == slots[i]) return true;
  return false;
}

String safeSlot(String slot) {
  slot.toLowerCase();
  if (!slotExists(slot)) return "last";
  return slot;
}

void saveRaw(const String &slot, uint16_t *raw, uint16_t length) {
  String key = "n_" + slot;
  preferences.putUShort(key.c_str(), length);
  preferences.putBytes(("r_" + slot).c_str(), raw, length * sizeof(uint16_t));
}

bool sendSlot(String slot) {
  slot = safeSlot(slot);
  uint16_t count = preferences.getUShort(("n_" + slot).c_str(), 0);
  if (count == 0 || count > IR_BUFFER_SIZE) {
    statusText = "No learned command for " + slot;
    screenDirty = true;
    return false;
  }
  uint16_t raw[IR_BUFFER_SIZE];
  size_t bytes = preferences.getBytes(("r_" + slot).c_str(), raw, count * sizeof(uint16_t));
  if (bytes != count * sizeof(uint16_t)) {
    statusText = "Saved IR data is incomplete";
    screenDirty = true;
    return false;
  }
  irsend.sendRaw(raw, count, IR_KHZ);
  statusText = "Sent: " + slot;
  screenDirty = true;
  return true;
}

void startLearning(String slot) {
  learningSlot = safeSlot(slot);
  learnStartedAt = millis();
  irrecv.enableIRIn();
  statusText = "Learning " + learningSlot + ": point remote at receiver";
  screenDirty = true;
}

void drawButton(int16_t x, int16_t y, int16_t w, int16_t h, const char *label, uint16_t color) {
  tft.fillRoundRect(x, y, w, h, 6, color);
  tft.drawRoundRect(x, y, w, h, 6, ILI9341_WHITE);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  int16_t tx = x + (w - (int16_t)strlen(label) * 12) / 2;
  tft.setCursor(tx, y + (h - 16) / 2);
  tft.print(label);
}

void drawScreen() {
  tft.fillScreen(ILI9341_NAVY);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(76, 10);
  tft.print("SMART AC");
  tft.setTextSize(1);
  tft.setCursor(12, 38);
  tft.print("IR remote learner + local control");

  tft.setTextSize(3);
  tft.setCursor(105, 58);
  tft.setTextColor(ILI9341_CYAN);
  tft.print("COOL");
  tft.setTextSize(3);
  tft.setCursor(122, 91);
  tft.setTextColor(ILI9341_WHITE);
  tft.print("24 C");

  drawButton(18, 132, 60, 36, "-", ILI9341_DARKCYAN);
  drawButton(242, 132, 60, 36, "+", ILI9341_DARKCYAN);
  drawButton(16, 178, 66, 34, "FAN", ILI9341_DARKGREEN);
  drawButton(91, 178, 70, 34, "SWING", ILI9341_DARKGREEN);
  drawButton(170, 178, 66, 34, "SLEEP", ILI9341_DARKGREEN);
  drawButton(245, 178, 59, 34, "PWR", ILI9341_MAROON);

  tft.fillRect(0, 216, 320, 24, ILI9341_BLACK);
  tft.setTextSize(1);
  tft.setTextColor(ILI9341_YELLOW);
  tft.setCursor(4, 219);
  if (!isnan(roomTemp)) {
    tft.printf("Room %.1f C  %.0f%%  ", roomTemp, roomHumidity);
  } else {
    tft.print("Room sensor starting... ");
  }
  tft.setTextColor(ILI9341_WHITE);
  String shortStatus = statusText;
  if (shortStatus.length() > 31) shortStatus = shortStatus.substring(0, 31);
  tft.print(shortStatus);
}

void handleTouch() {
  if (!touch.touched()) return;
  TS_Point p = touch.getPoint();
  // Typical 2.8-inch XPT2046 module calibration. Adjust these four limits if touch is offset.
  int16_t x = map(p.y, 250, 3800, 0, SCREEN_W);
  int16_t y = map(p.x, 250, 3800, SCREEN_H, 0);
  if (x < 0 || x >= SCREEN_W || y < 0 || y >= SCREEN_H) return;
  String slot;
  if (y >= 132 && y < 168 && x < 100) slot = "minus";
  else if (y >= 132 && y < 168 && x > 220) slot = "plus";
  else if (y >= 178 && x < 86) slot = "fan";
  else if (y >= 178 && x < 166) slot = "swing";
  else if (y >= 178 && x < 240) slot = "sleep";
  else if (y >= 178) slot = "power";
  if (slot.length()) sendSlot(slot);
  delay(180); // one touch produces one command
}

String htmlPage() {
  String page = F("<!doctype html><html><head><meta name=viewport content='width=device-width,initial-scale=1'><style>body{font-family:Arial;max-width:620px;margin:20px auto;padding:0 14px;background:#eef3f7;color:#18232d}button{padding:13px;margin:5px;border:0;border-radius:8px;background:#087e8b;color:white;font-size:16px}.learn{background:#6b4b9b}.power{background:#b23a48}code{word-break:break-all}</style></head><body><h1>Smart AC Controller</h1><p>");
  page += statusText;
  page += F("</p><p>IP: <code>");
  page += WiFi.isConnected() ? WiFi.localIP().toString() : WiFi.softAPIP().toString();
  page += F("</code></p><h2>Send learned command</h2>");
  for (uint8_t i = 0; i < SLOT_COUNT - 1; i++) {
    page += "<a href='/send?slot=" + String(slots[i]) + "'><button class='" + String(slots[i] == String("power") ? "power" : "") + "'>" + String(slots[i]) + "</button></a>";
  }
  page += F("<h2>Learn from original remote</h2><p>Tap a Learn button, then within 12 seconds hold the matching original-remote button 2-10 cm in front of the VS1838B.</p>");
  for (uint8_t i = 0; i < SLOT_COUNT - 1; i++) {
    page += "<a href='/learn?slot=" + String(slots[i]) + "'><button class='learn'>Learn " + String(slots[i]) + "</button></a>";
  }
  page += F("<p>For an AC remote, learn each complete state you need. Many AC remotes transmit the complete state, not a simple + or - command.</p></body></html>");
  return page;
}

void setupWeb() {
  server.on("/", HTTP_GET, []() { server.send(200, "text/html; charset=utf-8", htmlPage()); });
  server.on("/learn", HTTP_GET, []() { startLearning(server.arg("slot")); server.sendHeader("Location", "/"); server.send(303); });
  server.on("/send", HTTP_GET, []() { sendSlot(server.arg("slot")); server.sendHeader("Location", "/"); server.send(303); });
  server.on("/status", HTTP_GET, []() {
    String json = "{\"status\":\"" + statusText + "\",\"temperature\":" + (isnan(roomTemp) ? "null" : String(roomTemp, 1)) + ",\"humidity\":" + (isnan(roomHumidity) ? "null" : String(roomHumidity, 0)) + "}";
    server.send(200, "application/json", json);
  });
  server.begin();
}

void connectWiFi() {
  if (strlen(WIFI_SSID) == 0) {
    WiFi.mode(WIFI_AP);
    WiFi.softAP(SETUP_AP_NAME, SETUP_AP_PASSWORD);
    statusText = "Setup Wi-Fi: AC-Controller-Setup";
    return;
  }
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  uint32_t started = millis();
  while (WiFi.status() != WL_CONNECTED && millis() - started < 15000) delay(250);
  if (WiFi.status() == WL_CONNECTED) statusText = "Wi-Fi connected: " + WiFi.localIP().toString();
  else {
    WiFi.mode(WIFI_AP);
    WiFi.softAP(SETUP_AP_NAME, SETUP_AP_PASSWORD);
    statusText = "Home Wi-Fi failed; setup AP active";
  }
}

void checkLearning() {
  if (learningSlot.length() == 0) return;
  if (irrecv.decode(&results)) {
    uint16_t length = getCorrectedRawLength(&results);
    if (length > 0 && length <= IR_BUFFER_SIZE) {
      uint16_t *raw = resultToRawArray(&results);
      if (raw != nullptr) {
        saveRaw(learningSlot, raw, length);
        saveRaw("last", raw, length);
        statusText = "Learned " + learningSlot + " (" + String(length) + " timings)";
        delete[] raw;
      } else statusText = "IR capture memory error";
    } else statusText = "IR signal too long; move remote closer";
    irrecv.resume();
    learningSlot = "";
    screenDirty = true;
  } else if (millis() - learnStartedAt > LEARN_WINDOW_MS) {
    statusText = "Learning timed out - try again closer";
    learningSlot = "";
    screenDirty = true;
  }
}

void setup() {
  Serial.begin(115200);
  preferences.begin("smartac", false);
  SPI.begin(SPI_SCK_PIN, SPI_MISO_PIN, SPI_MOSI_PIN);
  tft.begin();
  tft.setRotation(1);
  touch.begin();
  touch.setRotation(1);
  dht.begin();
  irsend.begin();
  irrecv.enableIRIn();
  connectWiFi();
  setupWeb();
  drawScreen();
  Serial.println("Smart AC Controller ready");
  Serial.println(WiFi.isConnected() ? WiFi.localIP() : WiFi.softAPIP());
}

void loop() {
  server.handleClient();
  checkLearning();
  handleTouch();
  if (millis() - lastDhtRead >= 2500) {
    lastDhtRead = millis();
    float h = dht.readHumidity();
    float t = dht.readTemperature();
    if (!isnan(t) && !isnan(h) && (isnan(roomTemp) || t != roomTemp || h != roomHumidity)) {
      roomTemp = t;
      roomHumidity = h;
      screenDirty = true;
    }
  }
  if (screenDirty && millis() - lastScreenDraw >= 100) {
    lastScreenDraw = millis();
    screenDirty = false;
    drawScreen();
  }
}