Added LVGL sketch

Author: marqdevx

examples/Creating GUIs with LVGL/lvglCounter/lvglCounter.ino

@@ -0,0 +1,39 @@
+#include "Portenta_LittleVGL.h"
+
+static lv_obj_t *label;
+int counter = 0;
+
+static void updateCounterTask(lv_task_t *task) {
+  // Print the count to the Serial monitor
+  Serial.println(counter);
+
+  // Update the text of the label
+  lv_label_set_text_fmt(label, "%d" , counter);    
+
+  // Increase the count number
+  counter++;                                               
+}
+
+void setup() {  
+  Serial.begin(9600);
+
+  // Initialize Portenta's video interface
+  portenta_init_video();
+
+  // Setting up the label making it a child of the screen
+  label = lv_label_create(lv_scr_act(), NULL);
+
+  // Set the label's text
+  lv_label_set_text(label , "Counter");
+
+  // We move it to the center of the screen and align it centered
+  lv_obj_align(label, NULL, LV_ALIGN_CENTER, 0, 0);
+
+  // Create a task to update the counter
+  lv_task_create(updateCounterTask, 1000, LV_TASK_PRIO_MID, NULL);
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  lv_task_handler();
+}