diff --git a/README.md b/README.md
index 58b0263..db9519e 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ while(1) {
     ...
     if(timer_ticks == 5) {
         timer_ticks = 0;
-        
+
         button_ticks();
     }
 }
@@ -49,7 +49,7 @@ struct Button {
 	uint8_t  repeat: 4;
 	uint8_t  event : 4;
 	uint8_t  state : 3;
-	uint8_t  debounce_cnt : 3; 
+	uint8_t  debounce_cnt : 3;
 	uint8_t  active_level : 1;
 	uint8_t  button_level : 1;
 	uint8_t  (*hal_button_Level)(void);
@@ -69,7 +69,7 @@ PRESS_UP | 按键弹起，每次松开都触发
 PRESS_REPEAT | 重复按下触发，变量repeat计数连击次数
 SINGLE_CLICK | 单击按键事件
 DOUBLE_CLICK | 双击按键事件
-LONG_RRESS_START | 达到长按时间阈值时触发一次
+LONG_PRESS_START | 达到长按时间阈值时触发一次
 LONG_PRESS_HOLD | 长按期间一直触发
 
 
@@ -80,7 +80,7 @@ LONG_PRESS_HOLD | 长按期间一直触发
 
 struct Button btn1;
 
-int read_button1_GPIO() 
+int read_button1_GPIO()
 {
 	return HAL_GPIO_ReadPin(B1_GPIO_Port, B1_Pin);
 }
@@ -93,15 +93,15 @@ int main()
 	button_attach(&btn1, PRESS_REPEAT,     BTN1_PRESS_REPEAT_Handler);
 	button_attach(&btn1, SINGLE_CLICK,     BTN1_SINGLE_Click_Handler);
 	button_attach(&btn1, DOUBLE_CLICK,     BTN1_DOUBLE_Click_Handler);
-	button_attach(&btn1, LONG_RRESS_START, BTN1_LONG_RRESS_START_Handler);
+	button_attach(&btn1, LONG_PRESS_START, BTN1_LONG_PRESS_START_Handler);
 	button_attach(&btn2, LONG_PRESS_HOLD,  BTN1_LONG_PRESS_HOLD_Handler);
 	button_start(&btn1);
-	
+
 	//make the timer invoking the button_ticks() interval 5ms.
 	//This function is implemented by yourself.
-	__timer_start(button_ticks, 0, 5); 
-	
-	while(1) 
+	__timer_start(button_ticks, 0, 5);
+
+	while(1)
 	{}
 }
 
diff --git a/examples/example_callback.c b/examples/example_callback.c
index a7fbc6e..d774069 100644
--- a/examples/example_callback.c
+++ b/examples/example_callback.c
@@ -3,12 +3,12 @@
 struct Button btn1;
 struct Button btn2;
 
-uint8_t read_button1_GPIO() 
+uint8_t read_button1_GPIO()
 {
 	return HAL_GPIO_ReadPin(B1_GPIO_Port, B1_Pin);
 }
 
-uint8_t read_button2_GPIO() 
+uint8_t read_button2_GPIO()
 {
 	return HAL_GPIO_ReadPin(B2_GPIO_Port, B2_Pin);
 }
@@ -17,31 +17,31 @@ int main()
 {
 	button_init(&btn1, read_button1_GPIO, 0);
 	button_init(&btn2, read_button2_GPIO, 0);
-	
+
 	button_attach(&btn1, PRESS_DOWN,       BTN1_PRESS_DOWN_Handler);
 	button_attach(&btn1, PRESS_UP,         BTN1_PRESS_UP_Handler);
 	button_attach(&btn1, PRESS_REPEAT,     BTN1_PRESS_REPEAT_Handler);
 	button_attach(&btn1, SINGLE_CLICK,     BTN1_SINGLE_Click_Handler);
 	button_attach(&btn1, DOUBLE_CLICK,     BTN1_DOUBLE_Click_Handler);
-	button_attach(&btn1, LONG_RRESS_START, BTN1_LONG_RRESS_START_Handler);
+	button_attach(&btn1, LONG_PRESS_START, BTN1_LONG_PRESS_START_Handler);
 	button_attach(&btn1, LONG_PRESS_HOLD,  BTN1_LONG_PRESS_HOLD_Handler);
-	
+
 	button_attach(&btn2, PRESS_DOWN,       BTN2_PRESS_DOWN_Handler);
 	button_attach(&btn2, PRESS_UP,         BTN2_PRESS_UP_Handler);
 	button_attach(&btn2, PRESS_REPEAT,     BTN2_PRESS_REPEAT_Handler);
 	button_attach(&btn2, SINGLE_CLICK,     BTN2_SINGLE_Click_Handler);
 	button_attach(&btn2, DOUBLE_CLICK,     BTN2_DOUBLE_Click_Handler);
-	button_attach(&btn2, LONG_RRESS_START, BTN2_LONG_RRESS_START_Handler);
+	button_attach(&btn2, LONG_PRESS_START, BTN2_LONG_PRESS_START_Handler);
 	button_attach(&btn2, LONG_PRESS_HOLD,  BTN2_LONG_PRESS_HOLD_Handler);
-	
+
 	button_start(&btn1);
 	button_start(&btn2);
-	
+
 	//make the timer invoking the button_ticks() interval 5ms.
 	//This function is implemented by yourself.
-	__timer_start(button_ticks, 0, 5); 
-	
-	while(1) 
+	__timer_start(button_ticks, 0, 5);
+
+	while(1)
 	{}
 }
 
diff --git a/multi_button.c b/multi_button.c
index 5c1385b..3a96fa7 100644
--- a/multi_button.c
+++ b/multi_button.c
@@ -6,7 +6,7 @@
 #include "multi_button.h"
 
 #define EVENT_CB(ev)   if(handle->cb[ev])handle->cb[ev]((Button*)handle)
-	
+
 //button handle list head.
 static struct Button* head_handle = NULL;
 
@@ -93,8 +93,8 @@ void button_handler(struct Button* handle)
 			handle->state = 2;
 
 		} else if(handle->ticks > LONG_TICKS) {
-			handle->event = (uint8_t)LONG_RRESS_START;
-			EVENT_CB(LONG_RRESS_START);
+			handle->event = (uint8_t)LONG_PRESS_START;
+			EVENT_CB(LONG_PRESS_START);
 			handle->state = 5;
 		}
 		break;
@@ -103,7 +103,7 @@ void button_handler(struct Button* handle)
 		if(handle->button_level == handle->active_level) { //press down again
 			handle->event = (uint8_t)PRESS_DOWN;
 			EVENT_CB(PRESS_DOWN);
-			handle->repeat++;			
+			handle->repeat++;
 			EVENT_CB(PRESS_REPEAT); // repeat hit
 			handle->ticks = 0;
 			handle->state = 3;
diff --git a/multi_button.h b/multi_button.h
index 7bbb26f..6cf54d7 100644
--- a/multi_button.h
+++ b/multi_button.h
@@ -2,7 +2,7 @@
  * Copyright (c) 2016 Zibin Zheng <znbin@qq.com>
  * All rights reserved
  */
- 
+
 #ifndef _MULTI_BUTTON_H_
 #define _MULTI_BUTTON_H_
 
@@ -24,7 +24,7 @@ typedef enum {
 	PRESS_REPEAT,
 	SINGLE_CLICK,
 	DOUBLE_CLICK,
-	LONG_RRESS_START,
+	LONG_PRESS_START,
 	LONG_PRESS_HOLD,
 	number_of_event,
 	NONE_PRESS
@@ -35,7 +35,7 @@ typedef struct Button {
 	uint8_t  repeat : 4;
 	uint8_t  event : 4;
 	uint8_t  state : 3;
-	uint8_t  debounce_cnt : 3; 
+	uint8_t  debounce_cnt : 3;
 	uint8_t  active_level : 1;
 	uint8_t  button_level : 1;
 	uint8_t  (*hal_button_Level)(void);
@@ -43,9 +43,9 @@ typedef struct Button {
 	struct Button* next;
 }Button;
 
-#ifdef __cplusplus  
-extern "C" {  
-#endif  
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 void button_init(struct Button* handle, uint8_t(*pin_level)(), uint8_t active_level);
 void button_attach(struct Button* handle, PressEvent event, BtnCallback cb);
@@ -55,7 +55,7 @@ void button_stop(struct Button* handle);
 void button_ticks(void);
 
 #ifdef __cplusplus
-} 
+}
 #endif
 
 #endif