Description
LVGL prints only one buffer and then stops working.
What MCU/Processor/Board and compiler are you using?
Teensy 3.6, Arduino Studio 1.49.2
What do you want to achieve?
I’d like to display a button on screen.
What have you tried so far?
Followed the “porting” page and implemented all neccessary parts.
Code to reproduce
I use default lvgl_conf file, only changed dimensions to 320x240 and added logging.
Complete code of my .ino file follows.
#include "src\lvgl\lvgl.h"
#include <ILI9341_t3.h>
#include <XPT2046_Touchscreen.h>
#define DISPLAY_CS 10
#define DISPLAY_DC 9
#define DISPLAY_MOSI 11
#define DISPLAY_MISO 12
#define DISPLAY_SCK 13
#define DISPLAY_RST 255 // Not connected
#define TOUCH_CS 8
#define TOUCH_IRQ 23
#define TS_MINX 250
#define TS_MAXX 3800
#define TS_MINY 250
#define TS_MAXY 3800
#define LV_BUFFER_SIZE (320*10)
#define GUI_TIMER_MS 5
ILI9341_t3 tft(DISPLAY_CS, DISPLAY_DC, 255, DISPLAY_MOSI, DISPLAY_SCK, DISPLAY_MISO);
XPT2046_Touchscreen ts(TOUCH_CS, TOUCH_IRQ);
IntervalTimer guiTimer;
lv_disp_buf_t lvDisplayBuffer;
lv_color_t lvBuffer1[LV_BUFFER_SIZE];
lv_color_t lvBuffer2[LV_BUFFER_SIZE];
lv_obj_t * screen;
lv_obj_t * button;
void drawBuffer(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p)
{
/* DEBUG */
Serial.print("Printing buffer: ");
Serial.print(area->x1);
Serial.print(",");
Serial.print(area->y1);
Serial.print(" .. ");
Serial.print(area->x2);
Serial.print(",");
Serial.println(area->y2);
/* END DEBUG */
tft.writeRect(area->x1,
area->y1,
(area->x2 - area->x1 + 1),
(area->y2 - area->y1 + 1),
(uint16_t *)color_p);
Serial.print("End printing buffer");
}
bool readInput(lv_indev_drv_t * drv, lv_indev_data_t * data)
{
TS_Point p = ts.getPoint();
data->point.x = map(p.x, TS_MINX, TS_MAXX, 0, tft.width());
data->point.y = map(p.y, TS_MINY, TS_MAXY, 0, tft.height());
data->state = ts.touched() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
return false;
}
void timeGui()
{
lv_tick_inc(GUI_TIMER_MS);
}
#if LV_USE_LOG
void logCallback(lv_log_level_t level, const char * file, long unsigned int line, const char * fn_name, const char * dsc)
{
Serial.print(file);
Serial.print("\t");
Serial.print(fn_name);
Serial.print(" (line ");
Serial.print(line);
Serial.print(")\t");
Serial.println(dsc);
}
#endif
void setup() {
// put your setup code here, to run once:
// Start serial port
Serial.begin(9600);
while (!Serial) ;
tft.begin();
tft.setRotation(1);
tft.fillScreen(ILI9341_BLACK);
ts.begin();
ts.setRotation(1);
// Initialize LVGL
lv_init();
// Initialize display buffer
lv_disp_buf_init(&lvDisplayBuffer, lvBuffer1, lvBuffer2, LV_BUFFER_SIZE);
// Initialize display driver
lv_disp_drv_t disp_drv;
lv_disp_drv_init(&disp_drv);
disp_drv.buffer = &lvDisplayBuffer;
disp_drv.flush_cb = drawBuffer;
lv_disp_t * disp;
disp = lv_disp_drv_register(&disp_drv);
// Initialize input driver
lv_indev_drv_t indev_drv;
lv_indev_drv_init(&indev_drv);
indev_drv.type = LV_INDEV_TYPE_POINTER;
indev_drv.read_cb = readInput;
lv_indev_t * indev = lv_indev_drv_register(&indev_drv);
// Start the interval timer
guiTimer.begin(timeGui, GUI_TIMER_MS * 1000);
#if LV_USE_LOG
lv_log_register_print_cb(logCallback);
#endif
// Create controls
screen = lv_obj_create(nullptr, nullptr);
button = lv_btn_create(screen, nullptr);
lv_obj_set_pos(button, 10, 10);
lv_obj_set_size(button, 150, 50);
lv_scr_load(screen);
}
void loop() {
// put your main code here, to run repeatedly:
lv_task_handler();
}
Screenshot and/or video
I don’t have screenshot, but dump from the log from LVGL along with my own logs. It looks like following (I stripped the paths):
C:\...\src\lvgl\src\lv_core\lv_obj.c lv_obj_create (line 267) Screen create started
C:\...\src\lvgl\src\lv_core\lv_obj.c lv_obj_create (line 456) Object create ready
C:\..\src\lvgl\src\lv_widgets\lv_btn.c lv_btn_create (line 61) button create started
C:\...\src\lvgl\src\lv_widgets\lv_cont.c lv_cont_create (line 70) container create started
C:\...\src\lvgl\src\lv_core\lv_obj.c lv_obj_create (line 299) Object create started
C:\...\src\lvgl\src\lv_core\lv_obj.c lv_obj_create (line 456) Object create ready
C:\...\src\lv_widgets\lv_cont.c lv_cont_create (line 118) container created
C:\...\src\lvgl\src\lv_widgets\lv_btn.c lv_btn_create (line 106) button created
C:\...\lvgl\src\lv_misc\lv_task.c lv_task_handler (line 74) lv_task_handler started
C:\...\lvgl\src\lv_core\lv_refr.c _lv_disp_refr_task (line 177) lv_refr_task: started
Printing buffer: 0,0 .. 319,9
End printing buffer
Works like charm now.