How to use a function inside the ui_event file instead of void loop()

How to
1

What do you want to achieve?

Create a function inside ui_events that reads my sensors (i2c) every x seconds. If I put the function inside the void loop(), it makes the display unavailable during the reading so if I have 2 sensors with 900ms delay for reading each, its almost 2 sec without being able to interact with touch display and I have 4 of them… hahaha

What have you tried so far?

Searching on google, more searching… Searching… No luck

Screenshot or video

Others

  • SquareLine Studio version:1.1.1
  • Operating system: Windows 10
  • Target hardware: ESP32-S2 with ili9488 TFT Touch Display
2

LVGL provides timers, look here: Timers — LVGL documentation
I have also had great success making use of tasks using Scott Bezek task.h - see inside his SmartKnob GitHub project - scottbez1/smartknob: Haptic input knob with software-defined endstops and virtual detents (github.com)

Andy

3

Awesome, thanks for the advice and the fast response! I will look into it! Will let you know if it fots my project:)

4

@AndyFraser, I just got back home and looked at that lv_timer thing. I noticed that it is actually present in the void loop() as “lv_timer_handler();”. My question is, where do I place my custom function(s) in arduino/Squareline project for the timer to trigger it every x seconds? Here is a sample of my function:

float check_ph() {
  Wire.beginTransmission(ph_address);
  Wire.write("r");
  Wire.endTransmission();
  delay(900);
  Wire.requestFrom(ph_address, 32, 1);
  return_code = Wire.read(); // Not used

  while (Wire.available()) {
    in_char = Wire.read();
    ph_data[i] = in_char;
    i += 1;
    if (in_char == 0) {
      i = 0;
      break;
    }
  }
  ph_float=atof(ph_data);
  return ph_float;              //print the data.
}

And the result is then pushed to Squareline label and widget:

      lv_label_set_text(ui_Home_Ph_Label, phString3.c_str());
      lv_arc_set_value(ui_Home_PH_Meter, ph_val);

Thanks again :slight_smile:

5

Should I use the LVGL built-in task system? And if so, where should I put my code (what file and where in that file)? Thanks!!

6

Sorry for the late reply.

Note that LVGL timer are blocking. So what you do in them will block the UI and other timers.

I suggest used HW timers to ready from interrupt or so and only get the result with lv_timer.

After ui_init you can create the timers as described here:
https://docs.lvgl.io/master/overview/timer.html