diff --git a/global.h b/global.h
index 559ae06..652fe67 100644
--- a/global.h
+++ b/global.h
@@ -20,11 +20,25 @@
 /* system clock frequency in Hz */
 #define SYSTEM_CLOCK_FREQ 72000000
 
-/* LED is on pin 11/PA1 */
+/* LED pin */
+#ifdef SYSTEM_BOARD
+/* for system board LED is on pin 11/PA1 */
 #define LED_RCC RCC_GPIOA
 #define LED_PORT GPIOA
 #define LED_PIN	GPIO1
+#elif MAPLE_MINI
+/* for maple mini LED is on pin 19/PB1 */
+#define LED_RCC RCC_GPIOB
+#define LED_PORT GPIOB
+#define LED_PIN GPIO1
+#endif
 
+/* switch on LED */
+void led_on(void);
+/* switch off LED */
+void led_off(void);
+/* toggle LED */
+void led_toggle(void);
 /* default output (i.e. for printf) */
 int _write(int file, char *ptr, int len);