#include <TM1637Display.h>

#define CLK 2  // TM1637 CLK
#define DIO 3  // TM1637 DIO

// Create a TM1637 display object
TM1637Display display(CLK, DIO);

int testminutes = 5;
int testseconds = 7;
int MS = 1;
//-------------------------------------------------------------------
void setup() {
  Serial.begin(115200);
  display.clear();
  display.setBrightness(3);
  display.showNumberDecEx(0, 0b01000000, true);  // 00:00
}
//-------------------------------------------------------------------
void on_button_short_click() {
  switch (MS) {
    case 1:
      display.clear();
      display.showNumberDecEx(testminutes, 0b01000000, true, 2, 4);  // 05:__
      MS = 2;
      break;
    case 2:
      display.clear();
      display.showNumberDecEx(testseconds, 0b01000000, true, 2, 2);  // __:07
      MS = 1;
      break;
  }
}
//-------------------------------------------------------------------
void loop() {
   on_button_short_click();
   delay(500);
}