Programujeme vývojovou desku ESP32 s 3.5" TFT dotykovým displejem

#include <LovyanGFX.hpp>
#include <lvgl.h>

// --- NASTAVENÍ PINŮ ---
#define PIN_RED   4
#define PIN_GREEN 16
#define PIN_BLUE  17
#define PIN_BL    27 // Podsvícení

// Logika LED: Active Low (HIGH = Vypnuto, LOW = Zapnuto)
#define LED_OFF   HIGH
#define LED_ON    LOW

// --- OVLADAČ DISPLEJE (LovyanGFX) ---
class LGFX : public lgfx::LGFX_Device {
    lgfx::Panel_ST7796  _panel_instance;
    lgfx::Bus_SPI       _bus_instance;
    lgfx::Touch_XPT2046 _touch_instance;

public:
    LGFX(void) {
        {
            auto cfg = _bus_instance.config();
            cfg.spi_host = HSPI_HOST;
            cfg.spi_mode = 0;
            cfg.freq_write = 40000000;
            cfg.freq_read  = 16000000;
            cfg.pin_sclk = 14; 
            cfg.pin_mosi = 13;
            cfg.pin_miso = 12;
            cfg.pin_dc   = 2;
            cfg.dma_channel = 1; 
            _bus_instance.config(cfg);
            _panel_instance.setBus(&_bus_instance);
        }
        {
            auto cfg = _panel_instance.config();
            cfg.pin_cs           = 15;
            cfg.pin_rst          = -1;
            cfg.panel_width      = 320;
            cfg.panel_height     = 480;
            cfg.invert           = false;
            cfg.rgb_order        = false; 
            cfg.bus_shared       = true; 
            _panel_instance.config(cfg);
        }
        { 
            auto cfg = _touch_instance.config();
            // Kalibrace pro Sunton Resistive
            cfg.x_min      = 200;  
            cfg.x_max      = 3700; 
            cfg.y_min      = 200; 
            cfg.y_max      = 3700; 
            cfg.bus_shared = true; 
            cfg.spi_host = HSPI_HOST;
            cfg.freq = 2500000; 
            cfg.pin_sclk = 14;
            cfg.pin_mosi = 13;
            cfg.pin_miso = 12;
            cfg.pin_cs   = 33; 
            cfg.pin_int  = -1; // Polling mód (nutné!)
            _touch_instance.config(cfg);
            _panel_instance.setTouch(&_touch_instance);
        }
        setPanel(&_panel_instance);
    }
};

LGFX tft;

// --- PAMĚŤ A VYKRESLOVÁNÍ ---
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 480
#define BUF_SIZE (SCREEN_WIDTH * SCREEN_HEIGHT / 10)
static uint16_t draw_buf[BUF_SIZE]; 

void my_disp_flush(lv_display_t *disp, const lv_area_t *area, uint8_t *px_map) {
    uint32_t w = (area->x2 - area->x1 + 1);
    uint32_t h = (area->y2 - area->y1 + 1);
    if (tft.getStartCount() == 0) tft.endWrite();
    tft.pushImageDMA(area->x1, area->y1, w, h, (uint16_t*)px_map);
    lv_display_flush_ready(disp);
}

// --- ČTENÍ DOTYKU ---
void my_touch_read(lv_indev_t *indev, lv_indev_data_t *data) {
    uint16_t touchX, touchY;
    bool touched = tft.getTouch(&touchX, &touchY);
    if (touched) {
        data->state = LV_INDEV_STATE_PRESSED;
        
        // 1. Osa X je prohozená -> otočit
        data->point.x = SCREEN_WIDTH - touchX;

        // 2. Osa Y je v pořádku -> beze změny
        data->point.y = touchY;

        // Ochrana proti přetečení
        if(data->point.x < 0) data->point.x = 0;
        if(data->point.x >= SCREEN_WIDTH) data->point.x = SCREEN_WIDTH - 1;
        if(data->point.y < 0) data->point.y = 0;
        if(data->point.y >= SCREEN_HEIGHT) data->point.y = SCREEN_HEIGHT - 1;
        
    } else {
        data->state = LV_INDEV_STATE_RELEASED;
    }
}

// --- OBSLUHA TLAČÍTEK ---
static void btn_event_handler(lv_event_t * e) {
    int color_id = (int)(long)lv_event_get_user_data(e);
    
    // Zhasnout vše
    digitalWrite(PIN_RED, LED_OFF);
    digitalWrite(PIN_GREEN, LED_OFF);
    digitalWrite(PIN_BLUE, LED_OFF);

    // Rozsvítit vybranou
    switch(color_id) {
        case 1: digitalWrite(PIN_RED, LED_ON); break;
        case 2: digitalWrite(PIN_GREEN, LED_ON); break;
        case 3: digitalWrite(PIN_BLUE, LED_ON); break;
    }
}

void setup() {
    Serial.begin(115200);
    
    // 1. INIT PINŮ (Vypnuto při startu)
    pinMode(PIN_RED, OUTPUT);   digitalWrite(PIN_RED, LED_OFF);
    pinMode(PIN_GREEN, OUTPUT); digitalWrite(PIN_GREEN, LED_OFF);
    pinMode(PIN_BLUE, OUTPUT);  digitalWrite(PIN_BLUE, LED_OFF);
    pinMode(PIN_BL, OUTPUT);    digitalWrite(PIN_BL, HIGH);

    // 2. INIT DISPLEJE
    tft.init();
    tft.setRotation(0);
    tft.fillScreen(TFT_BLACK);
    
    // --- OPRAVA BAREV ---
    // Prohodí bajty barev (opravuje fialovou místo zelené)
    tft.setSwapBytes(true); 

    // 3. INIT LVGL
    lv_init();
    lv_display_t * disp = lv_display_create(SCREEN_WIDTH, SCREEN_HEIGHT);
    lv_display_set_buffers(disp, draw_buf, NULL, BUF_SIZE * 2, LV_DISPLAY_RENDER_MODE_PARTIAL);
    lv_display_set_flush_cb(disp, my_disp_flush);

    lv_indev_t * indev = lv_indev_create();
    lv_indev_set_type(indev, LV_INDEV_TYPE_POINTER);
    lv_indev_set_read_cb(indev, my_touch_read);

    // 4. GUI
    lv_obj_t * scr = lv_screen_active();
    
    // ČERVENÁ
    lv_obj_t * btn1 = lv_button_create(scr);
    lv_obj_set_size(btn1, 150, 100);
    lv_obj_align(btn1, LV_ALIGN_TOP_MID, 0, 30);
    lv_obj_set_style_bg_color(btn1, lv_palette_main(LV_PALETTE_RED), 0);
    lv_obj_add_event_cb(btn1, btn_event_handler, LV_EVENT_CLICKED, (void*)1);
    lv_label_set_text(lv_label_create(btn1), "CERVENA");

    // ZELENÁ
    lv_obj_t * btn2 = lv_button_create(scr);
    lv_obj_set_size(btn2, 150, 100);
    lv_obj_center(btn2);
    lv_obj_set_style_bg_color(btn2, lv_palette_main(LV_PALETTE_GREEN), 0);
    lv_obj_add_event_cb(btn2, btn_event_handler, LV_EVENT_CLICKED, (void*)2);
    lv_label_set_text(lv_label_create(btn2), "ZELENA");

    // MODRÁ
    lv_obj_t * btn3 = lv_button_create(scr);
    lv_obj_set_size(btn3, 150, 100);
    lv_obj_align(btn3, LV_ALIGN_BOTTOM_MID, 0, -30);
    lv_obj_set_style_bg_color(btn3, lv_palette_main(LV_PALETTE_BLUE), 0);
    lv_obj_add_event_cb(btn3, btn_event_handler, LV_EVENT_CLICKED, (void*)3);
    lv_label_set_text(lv_label_create(btn3), "MODRA");
}

void loop() {
    lv_timer_handler();
    lv_tick_inc(5);
    delay(5);
}