     long display_time = players[active_player].time_remaining_ms/100;
 
     ltoa(display_time, timea, 10);
-    for(int i = 0; i < strlen(players[active_player].display_time); i++) {
+    for(unsigned int i = 0; i < strlen(players[active_player].display_time); i++) {
       if(timea[i] != players[active_player].display_time[i]) {
           
         // draw a rect

    TFT(cs_2, dc_2, rst_2),
    "",
    0,
    btn_2_interrupt,
    handle_button_press_2
  }
};


}

typedef struct {
  unsigned int interrupt_number;
  void (*handler)();
} button;

button buttons[2] = {
  {
    interrupt_number: 0,
    handler: handle_button_press_1
  },
  {
    interrupt_number: 1,
    handler: handle_button_press_2
  }
};

typedef struct {
  long time_remaining_ms;
  long last_update_ms;
  TFT tft;
  char display_time[12];
  int display_width_chars;
  unsigned int interrupt_number;
  void (* handle_button_press)();
} player;

