make LED blink if error that stop the PID are present

stm-firmware/main.c

@@ -312,7 +312,7 @@ int main(void)
 		 *  it is tried to load it from SD card.
 		 */
 		if (systick_ticks_have_passed(quarter_sec_timestamp, 250)) {
-			led_set(1, 0);
+			led_set(1u, 0);
 			sd_old = sd_card_mounted;
 			sd_card_mounted = mount_sd_card_if_avail(sd_card_mounted);
 
@@ -325,6 +325,14 @@ int main(void)
 				}
 			}
 
+			/* Check if any flags are present, that disable the PID controller. Blink
+			 * LED 0 in this case
+			 */
+			if (oven_pid_get_status() == OVEN_PID_ABORTED)
+				led_set(0u, led_get(0u) ? 0 : 1);
+			else
+				led_set(0u, 0);
+
 			quarter_sec_timestamp = systick_get_global_tick();
 		}