add bluepill exception: don't blink LED which influences the RTC

main.c

@@ -231,7 +231,9 @@ void main(void)
 		}
 		while (rtc_internal_tick_flag) { // the internal RTC ticked
 			rtc_internal_tick_flag = false; // reset flag
+#if !defined(BLUE_PILL) // on the blue pill the LED is close to the 32.768 kHz oscillator and heavily influences it
 			led_toggle(); // toggle LED (good to indicate if main function is stuck)
+#endif
 			ticks_time = rtc_get_counter_val(); // copy time from internal RTC for processing
 			action = true; // action has been performed
 			if ((ticks_time%(60))==0) { // one minute passed