CYD35_resistive_template.ino

// =========================================================================
//                             GCYD35_Template.ino
// -------------------------------------------------------------------------
//                The ESP32-3248S035C Template Project (G-Series)
// =========================================================================
//
// Original code author: Marvin A Cabico (Developer & Systems Integrator) + Gemini LLM
//                       https://github.com/mcabico-ict/GCYD35_Template/tree/main
// Ported to resistive touch CYD by polprog
//
//  BOARD MODEL: ESP32-DA-WROOM Module
//  HARDWARE:    ST7796 Display Driver / XPT2046
//  Board name:  3.5" LCD Display, ESP32-32E 320x480 Resistance Touch

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

// LGFX Libraries (used for display and touch)
#define LGFX_USE_V1 
#include <LovyanGFX.hpp>

// PIN DEFINITIONS & CONFIGURATION
// Display Pins
#define TFT_CS   15  // Chip Select
#define TFT_SCK  14  // SPI Clock
#define TFT_MOSI 13  // MOSI (Data)
#define TFT_MISO 12  // MISO (currently unused in this SPI 3-wire config, but defined for completeness)
#define TFT_DC   2   // Data/Command
#define TFT_BL   27  // Backlight PWM

// XPT2046 pins
#define TOUCH_CS    33
#define TOUCH_SCK   14
#define TOUCH_MOSI  13
#define TOUCH_MISO  12
#define TOUCH_INT   36


// HARDWARE CONFIGURATION (CYD 3.5-inch Standard Pinout)
class LGFX : public lgfx::LGFX_Device
{
  lgfx::Panel_ST7796 _panel_instance;
  lgfx::Bus_SPI _bus_instance;
  lgfx::Light_PWM _light_instance;
  lgfx::Touch_XPT2046 _touch_instance;

public:
  LGFX(void)
  {
    // SPI Bus Setup
    {
      auto cfg = _bus_instance.config();
      cfg.spi_host = HSPI_HOST;
      cfg.spi_mode = 0;
      cfg.freq_write = 80000000;
      cfg.freq_read = 40000000;
      cfg.spi_3wire = true;
      cfg.use_lock = true;
      cfg.dma_channel = SPI_DMA_CH_AUTO;
      cfg.pin_sclk = TFT_SCK; 
      cfg.pin_mosi = TFT_MOSI;
      cfg.pin_miso = TFT_MISO;
      cfg.pin_dc = TFT_DC;    
      _bus_instance.config(cfg);
      _panel_instance.setBus(&_bus_instance);
    }
    // Display Panel Setup
    {
      auto cfg = _panel_instance.config();
      cfg.pin_cs = TFT_CS;   
      cfg.panel_width = 320;
      cfg.panel_height = 480;
      cfg.bus_shared = true;
      _panel_instance.config(cfg);
    }
    // Backlight Setup
    {
      auto cfg = _light_instance.config();
      cfg.pin_bl = TFT_BL; 
      cfg.invert = false;
      cfg.freq = 1200;
      cfg.pwm_channel = 7;
      _light_instance.config(cfg);
      _panel_instance.setLight(&_light_instance);
    }
    // Touch Setup (GT911)
    {
      auto cfg = _touch_instance.config();
      cfg.spi_host = HSPI_HOST;
      cfg.bus_shared = true;
      cfg.pin_int = -1; //TOUCH_INT;
      cfg.pin_sclk = TOUCH_SCK;
      cfg.pin_mosi = TOUCH_MOSI;
      cfg.pin_miso = TOUCH_MISO;
      cfg.pin_cs = TOUCH_CS;
      // Calibration coordinates for 320x480 panel (adjust if needed)
      cfg.x_min = 200;
      cfg.x_max = 3800;
      cfg.y_min = 3900;
      cfg.y_max = 300;
      _touch_instance.config(cfg);
      _panel_instance.setTouch(&_touch_instance);
    }
    setPanel(&_panel_instance);
  }
};
LGFX tft;


// Define a structure to hold button properties
struct Button {
    int x; // Top-left X coordinate
    int y; // Top-left Y coordinate
    int w; // Width
    int h; // Height
    const char* label;
    uint16_t color;
    uint16_t pressedColor;
    bool isPressed;
};

// Array of Button definitions for a 480x320 landscape screen
Button buttons[] = {
    // x, y, w, h, label, color (Light Gray), pressedColor (Black), isPressed
    {30, 120, 80, 80, "LEFT", TFT_LIGHTGREY, TFT_BLACK, false},     
    {370, 120, 80, 80, "RIGHT", TFT_LIGHTGREY, TFT_BLACK, false},   
    {180, 30, 120, 60, "TOP", TFT_LIGHTGREY, TFT_BLACK, false},   
    {180, 230, 120, 60, "BOTTOM", TFT_LIGHTGREY, TFT_BLACK, false}, 
    {180, 120, 120, 80, "CLEAR", TFT_LIGHTGREY, TFT_BLACK, false}    // Label changed to CLEAR
};
const int NUM_BUTTONS = sizeof(buttons) / sizeof(buttons[0]);

void drawButton(const Button& btn, bool pressed);
bool isTouchInside(int touchX, int touchY, const Button& btn);

void drawButton(const Button& btn, bool pressed) {
    uint16_t fillColor = pressed ? btn.pressedColor : btn.color;
    uint16_t borderColor = TFT_WHITE;
    uint16_t textColor = TFT_WHITE;
    
    // Draw rounded rectangle button
    tft.fillRoundRect(btn.x, btn.y, btn.w, btn.h, 8, fillColor);
    tft.drawRoundRect(btn.x, btn.y, btn.w, btn.h, 8, borderColor);
    
    // Draw label
    tft.setFont(&fonts::Font2);
    tft.setTextColor(textColor, fillColor);
    tft.setTextDatum(middle_center);
    int centerX = btn.x + (btn.w / 2);
    int centerY = btn.y + (btn.h / 2);
    tft.drawString(btn.label, centerX, centerY);
}

bool isTouchInside(int touchX, int touchY, const Button& btn) {
    return (touchX >= btn.x && touchX <= (btn.x + btn.w) &&
            touchY >= btn.y && touchY <= (btn.y + btn.h));
}


void repaint(){

  tft.fillScreen(TFT_BLACK);

  tft.setFont(&fonts::Font4);
  tft.setTextColor(TFT_CYAN, TFT_BLACK);
  tft.setTextDatum(top_center);
  tft.drawString("GCYD35 Touch Test Template", tft.width() / 2, 5);
  
  for (int i = 0; i < NUM_BUTTONS; i++) {
    buttons[i].isPressed = false; // Ensure state is reset
    drawButton(buttons[i], false);
  }
  
}

void setup() {
  Serial.begin(115200); 
  Serial.println("\n--- GCYD35 Start ---");
  
  // 1. Initialize LGFX
  tft.begin();
  tft.setRotation(1); // Set to Landscape (480x320)
  tft.setBrightness(255);
  tft.fillScreen(TFT_BLACK);
  
  repaint(); 
}

// --- MAIN LOOP ---
void loop() {
  uint16_t x, y;
  static uint16_t i = 0;
  // Check for touch input
  bool touched = tft.getTouchRaw(&x, &y); //Raw touch readout is useful to adjust the config
  bool buttonWasHit = false;

  if(touched) {
    Serial.printf("touched!! x=%d y=%d\n", x, y);
  }
  
  touched = tft.getTouch(&x, &y);

  // Iterate through  all buttons
  for (int i = 0; i < NUM_BUTTONS; i++) {
    bool inside = isTouchInside(x, y, buttons[i]);
    
    // Logic: 
    // If touched AND inside AND button was NOT already pressed -> change state to pressed
    if (touched && inside && !buttons[i].isPressed) {
      buttons[i].isPressed = true;
      drawButton(buttons[i], true);
      Serial.printf("Button '%s' Pressed at (%d, %d)\n", buttons[i].label, x, y);

      // --- CLEAR ACTION LOGIC ---
      if (strcmp(buttons[i].label, "CLEAR") == 0) {
        repaint();
      }
      // --- END CLEAR ACTION LOGIC ---
      
      buttonWasHit = true; // Button was hit (either the press or a hold)
    } 
    // If NOT touched OR NOT inside AND button WAS pressed -> change state to released
    else if ((!touched || !inside) && buttons[i].isPressed) {
      buttons[i].isPressed = false;
      drawButton(buttons[i], false);
      Serial.printf("Button '%s' Released\n", buttons[i].label);
    }
    
    // If touched and inside (even if held), we stop the drawing function
    if (touched && inside) {
        buttonWasHit = true;
    }
  }
  
  if (touched && !buttonWasHit) {
    // Draw a small X at the touched pixel
    tft.drawLine(x-3, y-3, x+3, y+3, TFT_RED);
    tft.drawLine(x-3, y+3, x+3, y-3, TFT_RED);
    
  }
  
  delay(20); 
}