fix LED flashing

src/core/led.cpp

@@ -59,11 +59,16 @@ bool LED::loop(uint8_t healthcheck, bool button_busy) {
      // the user-requested LED blink always has preference
      if (!is_user_led_blink_) {
          // check for button press.
-        // if button is pressed, show LED (yellow on RGB LED, on/off on standard LED)
+         // while the button is held show the LED (yellow on RGB LED, on/off on standard LED),
-        // it will turn off on the next loop cycle
+         // and on release go back to the default state and re-check the health on the next cycle
          if (last_button_busy_ != button_busy) {
              last_button_busy_ = button_busy;
-            set_led(button_busy ? Color::OFF : Color::YELLOW); // Yellow
+             if (button_busy) {
+                 set_led(Color::YELLOW); // Yellow
+             } else {
+                 reset_led();
+                 previous_healthcheck_ = System::HEALTHCHECK_RESET;
+             }
              return false;
          }
  
@@ -104,6 +109,12 @@ bool LED::loop(uint8_t healthcheck, bool button_busy) {
                  color_steps_[2] = Color::BLUE; // blue, no network and no bus
              }
          }
+ 
+         // there's nothing to flash, so leave the LED in the state reset_led() gave it.
+         // Running the sequence here would keep writing Color::OFF and a healthy system would never show green.
+         if (healthcheck == 0 || button_busy) {
+             return false;
+         }
      }
  
      // show the LED status based on the healthcheck and button busy status
@@ -119,6 +130,11 @@ void LED::reset_led() {
      color_steps_[0] = Color::OFF;
      color_steps_[1] = Color::OFF;
      color_steps_[2] = Color::OFF;
+ 
+     // rewind the sequence so it starts from the top if the health degrades again
+     led_long_timer_  = 1; // 1 will kick it off immediately
+     led_short_timer_ = 0;
+     led_flash_step_  = 0;
  }
  
  // LED flash every few ms and then perform a factory reset