diff --git a/stm32l100c_discovery.h b/stm32l100c_discovery.h
--- a/stm32l100c_discovery.h
+++ b/stm32l100c_discovery.h
@@ -27,20 +27,20 @@ typedef enum
 #define LEDn                             2
 
 #define LED3_PIN                         GPIO_Pin_9
-#define LED3_GPIO_PORT                   GPIOC
-#define LED3_GPIO_CLK                    RCC_AHBPeriph_GPIOC
+#define LED3_GPIO_PORT                   GPIOB
+#define LED3_GPIO_CLK                    RCC_AHBPeriph_GPIOB
   
-#define LED4_PIN                         GPIO_Pin_8
-#define LED4_GPIO_PORT                   GPIOC
-#define LED4_GPIO_CLK                    RCC_AHBPeriph_GPIOC
+#define LED4_PIN                         GPIO_Pin_15
+#define LED4_GPIO_PORT                   GPIOA
+#define LED4_GPIO_CLK                    RCC_AHBPeriph_GPIOA
 
 #define BUTTONn                          1
 
-#define USER_BUTTON_PIN                GPIO_Pin_0
-#define USER_BUTTON_GPIO_PORT          GPIOA
-#define USER_BUTTON_GPIO_CLK           RCC_AHBPeriph_GPIOA
+#define USER_BUTTON_PIN                GPIO_Pin_3
+#define USER_BUTTON_GPIO_PORT          GPIOB
+#define USER_BUTTON_GPIO_CLK           RCC_AHBPeriph_GPIOB
 #define USER_BUTTON_EXTI_LINE          EXTI_Line0
-#define USER_BUTTON_EXTI_PORT_SOURCE   EXTI_PortSourceGPIOA
+#define USER_BUTTON_EXTI_PORT_SOURCE   EXTI_PortSourceGPIOB
 #define USER_BUTTON_EXTI_PIN_SOURCE    EXTI_PinSource0
 #define USER_BUTTON_EXTI_IRQn          EXTI0_IRQn