Good day, I'm new to programming and created this sketch through "copy and paste".
I'm using e ESP32 Dev board with TFT 3.2inch display ( ILI9341)
i created a UI with squareline studio and exported it into my sketch. The UI loads and everything is fine but as soon as i toggle the switch the screen goes white. The button still toggles and sends hex code but i cant see anything. Im using VSPI for display and HSPI for touch. Cant get it to work on the same bus. Please have a look at my code (.ino)
i tested the code without the lv_obj_add_event_cb() the the button still toggles but the display doesn't disappear. So it looks like "lv_obj_add_event_cb()" is causing the UI to disappear
#include <Arduino.h>
#include <lvgl.h>
#include <TFT_eSPI.h>
#include <XPT2046_Touchscreen.h>
#include "ui_events.h"
#include "ui.h" // SquareLine exported UI
#include "rs485_modbus.h"
#include "rs485_commands.h"
// ================== TFT SPI pins ==================
//#define TFT_MOSI 13
//#define TFT_MISO 12
//#define TFT_SCLK 14
//#define TFT_CS 15
//#define TFT_DC 2
//#define TFT_RST -1 // EN pin reset
//#define TFT_LED 21
TFT_eSPI tft = TFT_eSPI(); // TFT instance
// ================== Touch ==================
SPIClass SPI_TOUCH(HSPI);
#define TOUCH_IRQ 36
#define TOUCH_CS 33
XPT2046_Touchscreen ts(TOUCH_CS, TOUCH_IRQ);
// ================== RS485 ==================
#define RXD2 16
#define TXD2 17
#define RS485_DE_RE 4
#define LV_TICK_CUSTOM 0
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 240
volatile bool ui_ready = false;
volatile bool rs485_send_on = false;
volatile bool rs485_send_off = false;
static uint32_t last_lvgl_tick = 0;
// ================== LVGL ==================
static lv_disp_draw_buf_t draw_buf;
static lv_color_t buf1[320 * 40];
//
// Touch read callback///////////////////////////////////////////////////
void touch_read(lv_indev_drv_t * indev, lv_indev_data_t * data)
{
if (!ui_ready) {
data->state = LV_INDEV_STATE_RELEASED;
return;
}
TS_Point p = ts.getPoint();
if (p.z < 300 || p.x == 0 || p.y == 0) {
data->state = LV_INDEV_STATE_RELEASED;
return;
}
// Map raw values to screen coordinates
int16_t x = map(p.x, 351, 3536, 0, 319);
int16_t y = map(p.y, 403, 3815, 0, 239); // inverted Y
// Clamp
x = constrain(x, 0, 319);
y = constrain(y, 0, 239);
data->state = LV_INDEV_STATE_PRESSED;
data->point.x = x;
data->point.y = y;
// Debug
Serial.printf("TOUCH → X=%d Y=%d Z=%d\n", x, y, p.z);
}
//================= LVGL display flush=======================================
// ----------------------------------------------------------------------------------
void my_disp_flush(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
{
tft.startWrite();
tft.setAddrWindow(area->x1, area->y1,
area->x2 - area->x1 + 1,
area->y2 - area->y1 + 1);
tft.pushColors((uint16_t*)color_p,
(area->x2 - area->x1 + 1) * (area->y2 - area->y1 + 1),
true);
tft.endWrite();
lv_disp_flush_ready(disp);
}
// =================Send RS485 frame====================
void sendRS485(uint8_t* frame, uint8_t len) {
digitalWrite(RS485_DE_RE, HIGH); // TX mode
delay(2);
RS485.write(frame, len);
RS485.flush();
delay(2);
digitalWrite(RS485_DE_RE, LOW); // RX mode
}
hw_timer_t * lvgl_timer = NULL;
// ================== Setup ==================
void setup() {
Serial.begin(115200);
delay(100);
Serial.println("🚀 Setup start");
// ================= RS485 =================
rs485_init();
Serial.println("✅ RS485 initialized");
// ================= LVGL =================
Serial.println("Initializing LVGL...");
lv_init();
lv_disp_draw_buf_init(&draw_buf, buf1, NULL, 320 * 40);
static lv_disp_drv_t disp_drv;
lv_disp_drv_init(&disp_drv);
disp_drv.hor_res = 320;
disp_drv.ver_res = 240;
disp_drv.flush_cb = my_disp_flush;
disp_drv.draw_buf = &draw_buf;
lv_disp_drv_register(&disp_drv);
// ================= INPUT =================
static lv_indev_drv_t indev_drv;
lv_indev_drv_init(&indev_drv);
indev_drv.type = LV_INDEV_TYPE_POINTER;
indev_drv.read_cb = touch_read;
indev_drv.disp = lv_disp_get_default();
lv_indev_drv_register(&indev_drv);
// ================= TFT FIRST =================
Serial.println("Initializing TFT...");
SPI.begin(14, 12, 13); // VSPI for TFT
tft.begin();
tft.setRotation(1);
tft.fillScreen(TFT_BLACK);
Serial.println("✅ TFT initialized");
// ================= TOUCH (HSPI) =================
Serial.println("Initializing touch...");
SPI_TOUCH.begin(25, 39, 32, 33); // HSPI for touch
ts.begin(SPI_TOUCH);
ts.setRotation(3);
Serial.println("✅ Touch initialized");
// ================= UI LAST =================
Serial.println("Initializing UI...");
ui_init();
ui_ready = true;
lv_obj_add_event_cb(
ui_OnSwitch,
OnSwitch_event_cb,
LV_EVENT_CLICKED,
NULL
);
// lv_refr_now(NULL);
Serial.println("✅ UI initialized");
Serial.println("🏁 Setup complete");
}
// ================== Loop ==================
void loop()
{
uint32_t now = millis();
uint32_t diff = now - last_lvgl_tick;
if (diff > 0) {
lv_tick_inc(diff);
last_lvgl_tick = now;
}
lv_timer_handler();
if (rs485_send_on) {
rs485_send_on = false;
sendRS485(relayON, relayON_len);
}
if (rs485_send_off) {
rs485_send_off = false;
sendRS485(relayOFF, relayOFF_len);
}
delay(2);
}