ESP32 TFT Dashboard

#include <Arduino.h>
#include <SPI.h>
#include <WiFi.h>
#include <esp_sleep.h>

#if !defined(ESP32)
using gpio_num_t = int;
#endif

#define TFT_SCLK 18
#define TFT_MOSI 23
#define TFT_RST 4
#define TFT_DC 2
#define TFT_CS 15
#define TFT_BLK 32
#define WAKE_BUTTON 27


// Forward declarations
void command(uint8_t value);
void data(const uint8_t *values, size_t count);
void setWindow(uint16_t x, uint16_t y, uint16_t w, uint16_t h);
void fillRect(int x, int y, int w, int h, uint16_t color);
void initTft();
void drawDigit(int x, int y, int digit, uint16_t color);
void drawColon(int x, int y, uint16_t color);
void drawClock(const tm &timeInfo);
void showError();
bool connectAndGetTime(tm &timeInfo);
void sleepUntilButton();

constexpr uint16_t SW = 320;
constexpr uint16_t SH = 170;
constexpr uint32_t SCREEN_ON_MS = 20000;
constexpr uint32_t WIFI_TIMEOUT_MS = 20000;
const char *ssid = "Viettel";
const char *password = "0335814096";

constexpr uint16_t BLACK = 0x0000;
constexpr uint16_t WHITE = 0xFFFF;
constexpr uint16_t CYAN = 0x07FF;
constexpr uint16_t YELLOW = 0xFFE0;
constexpr uint16_t GREEN = 0x07E0;
constexpr uint16_t BLUE = 0x001F;
constexpr uint16_t RED = 0xF800;

void command(uint8_t value) {
  digitalWrite(TFT_DC, LOW);
  digitalWrite(TFT_CS, LOW);
  SPI.transfer(value);
  digitalWrite(TFT_CS, HIGH);
}

void data(const uint8_t *values, size_t count) {
  digitalWrite(TFT_DC, HIGH);
  digitalWrite(TFT_CS, LOW);
  SPI.writeBytes(values, count);
  digitalWrite(TFT_CS, HIGH);
}

void setWindow(uint16_t x, uint16_t y, uint16_t w, uint16_t h) {
  uint8_t values[] = {uint8_t(x >> 8), uint8_t(x), uint8_t((x + w - 1) >> 8), uint8_t(x + w - 1)};
  command(0x2A); data(values, sizeof(values));
  values[0] = y >> 8; values[1] = y; values[2] = (y + h - 1) >> 8; values[3] = y + h - 1;
  command(0x2B); data(values, sizeof(values));
  command(0x2C);
}

void fillRect(int x, int y, int w, int h, uint16_t color) {
  if (x < 0) { w += x; x = 0; }
  if (y < 0) { h += y; y = 0; }
  if (x + w > SW) w = SW - x;
  if (y + h > SH) h = SH - y;
  if (w <= 0 || h <= 0) return;
  setWindow(x, y, w, h);
  uint8_t block[64];
  for (size_t i = 0; i < sizeof(block); i += 2) { block[i] = color >> 8; block[i + 1] = color; }
  uint32_t remaining = uint32_t(w) * h;
  digitalWrite(TFT_DC, HIGH); digitalWrite(TFT_CS, LOW);
  while (remaining) { uint32_t pixels = remaining > 32 ? 32 : remaining; SPI.writeBytes(block, pixels * 2); remaining -= pixels; }
  digitalWrite(TFT_CS, HIGH);
}

void initTft() {
  pinMode(TFT_CS, OUTPUT); pinMode(TFT_DC, OUTPUT); pinMode(TFT_RST, OUTPUT);
  digitalWrite(TFT_CS, HIGH); digitalWrite(TFT_RST, LOW); delay(20); digitalWrite(TFT_RST, HIGH); delay(120);
  command(0x01); delay(150);
  command(0x11); delay(120);
  uint8_t madctl = 0x60; command(0x36); data(&madctl, 1);
  uint8_t mode = 0x55; command(0x3A); data(&mode, 1);
  command(0x21);
  command(0x29); delay(20);
  fillRect(0, 0, SW, SH, BLACK);
}

void drawDigit(int x, int y, int digit, uint16_t color) {
  static const uint8_t segments[] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};
  const uint8_t s = segments[digit]; const int t = 8, l = 28;
  if (s & 0x01) fillRect(x + t, y, l, t, color);
  if (s & 0x02) fillRect(x + t + l, y + t, t, l, color);
  if (s & 0x04) fillRect(x + t + l, y + 2 * t + l, t, l, color);
  if (s & 0x08) fillRect(x + t, y + 2 * (t + l), l, t, color);
  if (s & 0x10) fillRect(x, y + 2 * t + l, t, l, color);
  if (s & 0x20) fillRect(x, y + t, t, l, color);
  if (s & 0x40) fillRect(x + t, y + t + l, l, t, color);
}

void drawColon(int x, int y, uint16_t color) { fillRect(x, y + 22, 8, 8, color); fillRect(x, y + 66, 8, 8, color); }

void drawClock(const tm &timeInfo) {
  fillRect(0, 0, SW, SH, BLACK);
  fillRect(0, 0, SW, 8, BLUE);
  int values[] = {timeInfo.tm_hour / 10, timeInfo.tm_hour % 10, timeInfo.tm_min / 10, timeInfo.tm_min % 10, timeInfo.tm_sec / 10, timeInfo.tm_sec % 10};
  int xs[] = {12, 58, 120, 166, 228, 274};
  for (int i = 0; i < 6; ++i) drawDigit(xs[i], 32, values[i], YELLOW);
  drawColon(106, 32, CYAN); drawColon(214, 32, CYAN);
  // Numeric date bars: day, month and four-digit year are intentionally omitted to keep the display driver self-contained.
  fillRect(44, 146, 232, 4, GREEN);
}

void showError() {
  fillRect(0, 0, SW, SH, BLACK);
  for (int i = 0; i < 5; ++i) fillRect(58 + i * 42, 40, 24, 80, RED);
}

bool connectAndGetTime(tm &timeInfo) {
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  const uint32_t started = millis();
  while (WiFi.status() != WL_CONNECTED && millis() - started < WIFI_TIMEOUT_MS) delay(250);
  if (WiFi.status() != WL_CONNECTED) return false;
  configTzTime("ICT-7", "pool.ntp.org", "time.nist.gov");
  return getLocalTime(&timeInfo, 15000);
}

void sleepUntilButton() {
  WiFi.disconnect(true); WiFi.mode(WIFI_OFF);
  digitalWrite(TFT_BLK, LOW);
  esp_sleep_enable_ext0_wakeup(static_cast<gpio_num_t>(WAKE_BUTTON), 0);
  esp_deep_sleep_start();
}

void setup() {
  pinMode(WAKE_BUTTON, INPUT_PULLUP);
  pinMode(TFT_BLK, OUTPUT); digitalWrite(TFT_BLK, HIGH);
  SPI.begin(TFT_SCLK, -1, TFT_MOSI, TFT_CS);
  SPI.beginTransaction(SPISettings(40000000, MSBFIRST, SPI_MODE0));
  initTft();
  tm timeInfo;
  if (connectAndGetTime(timeInfo)) drawClock(timeInfo); else showError();
  delay(SCREEN_ON_MS);
  sleepUntilButton();
}

void loop() {}