diff --git a/main.c b/main.c
index 69dd0ea..3b4f990 100644
--- a/main.c
+++ b/main.c
@@ -11,6 +11,12 @@ volatile char nmea_sentence[MAX_FIELD_SIZE];
 volatile uint8_t nmea_index = 0;
 volatile bool nmea_ready = false;
 
+void GPIO_PORT_F_init(void);
+void GPIO_PORT_B_init(void);
+void UART1_WRITE(char data);
+void control_leds_based_on_speed(float speed_kmh);
+void process_nmea_sentence(const char *nmea_sentence);
+
 
 void GPIO_PORT_F_init(void)
 {