Cleanup and structirng

src/external_interfacing/leds.h

@@ -0,0 +1,12 @@
+#include <Arduino.h>
+
+#define LED_1 4
+#define LED_2 2
+#define LED_3 15
+#define LED_4 13
+#define LED_5 12
+#define LED_RED 14
+
+void display_percentage(float percentage);
+void display_error_code(byte err_code);
+void display_task(void* parameter);