diff --git a/Makefile b/Makefile
index 2be11d6..87314ae 100755
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@ INC += -I$(IDIR)
 TARGET = $(BIN_PATH)/test 
 
 C_SRCS += examples/test_linux.c
-C_SRCS += multi_timer.c
+C_SRCS += MultiTimer.c
 OBJ := $(patsubst %.c,%.o,$(filter %.c,$(addprefix $(SRC_PATH)/,$(C_SRCS))))
 TARGET_OBJ := $(addprefix $(OBJ_PATH)/,$(OBJ))
 
diff --git a/MultiTimer.c b/MultiTimer.c
index 394372d..75de835 100644
--- a/MultiTimer.c
+++ b/MultiTimer.c
@@ -7,46 +7,18 @@ static MultiTimer* timerList = NULL;
 // Timer tick
 static PlatformTicksFunction_t platformTicksFunction = NULL;
 
-/**
- * @brief 
- * 
- * @param ticksFunc 
- * @return int 
- */
 int MultiTimerInstall(PlatformTicksFunction_t ticksFunc)
 {
     platformTicksFunction = ticksFunc;
     return 0;
 }
 
-/**
-  * @brief  Initializes the timer struct handle.
-  * @param  handle: the timer handle strcut.
-  * @param  timeout_cb: deadline callback.
-  * @param  repeat: repeat interval time.
-  * @retval None
-  */
-int MultiTimerInit(MultiTimer* timer, uint32_t period, MultiTimerCallback_t cb, void* userData)
+int MultiTimerStart(MultiTimer* timer, uint32_t timing, MultiTimerCallback_t callback, void* userData)
 {
-    if (!timer || !cb) {
+    if (!timer || !callback) {
         return -1;
     }
-    timer->callback = cb;
-    timer->userData = userData;
-    timer->period = period;
-    return 0;
-}
-
-/**
-  * @brief  Start the timer work, add the handle into work list.
-  * @param  handle: target handle strcut.
-  * @param  deadline: Set the start time.
-  * @retval 0: succeed. -1: already exist.
-  */
-int MultiTimerStart(MultiTimer* timer, uint32_t startTime)
-{
     MultiTimer** nextTimer = &timerList;
-
     /* Remove the existing target timer. */
     for (; *nextTimer; nextTimer = &(*nextTimer)->next) {
         if (timer == *nextTimer) {
@@ -55,8 +27,10 @@ int MultiTimerStart(MultiTimer* timer, uint32_t startTime)
         }
     }
 
-    /* New deadline time. */
-    timer->deadline = platformTicksFunction() + startTime;
+    /* Init timer. */
+    timer->deadline = platformTicksFunction() + timing;
+    timer->callback = callback;
+    timer->userData = userData;
 
     /* Insert timer. */
     for (nextTimer = &timerList;; nextTimer = &(*nextTimer)->next) {
@@ -74,15 +48,9 @@ int MultiTimerStart(MultiTimer* timer, uint32_t startTime)
     return 0;
 }
 
-/**
-  * @brief  Stop the timer work, remove the handle off work list.
-  * @param  handle: target handle strcut.
-  * @retval None
-  */
 int MultiTimerStop(MultiTimer* timer)
 {
     MultiTimer** nextTimer = &timerList;
-
     /* Find and remove timer. */
     for (; *nextTimer; nextTimer = &(*nextTimer)->next) {
         MultiTimer* entry = *nextTimer;
@@ -94,29 +62,25 @@ int MultiTimerStop(MultiTimer* timer)
     return 0;
 }
 
-/**
-  * @brief  main loop.
-  * @param  None.
-  * @retval None
-  */
-void MultiTimerYield(void)
+int MultiTimerYield(void)
 {
     MultiTimer** nextTimer = &timerList;
-
     for (; *nextTimer; nextTimer = &(*nextTimer)->next) {
         MultiTimer* entry = *nextTimer;
         /* Sorted list, just process with the front part. */
         if (entry->deadline > platformTicksFunction()) {
-            return;
+            return (int)(entry->deadline - platformTicksFunction());
         }
         /* remove expired timer from list */
         *nextTimer = entry->next;
 
-        if (entry->period) {
-            MultiTimerStart(entry, entry->period);
-        }
+        /* call callback */
         if (entry->callback) {
             entry->callback(entry, entry->userData);
         }
+        if (entry->next == NULL) {
+            return 0;
+        }
     }
+    return 0;
 }
diff --git a/MultiTimer.h b/MultiTimer.h
index f33ecf1..60eb45f 100644
--- a/MultiTimer.h
+++ b/MultiTimer.h
@@ -16,20 +16,43 @@ typedef void (*MultiTimerCallback_t)(MultiTimer* timer, void* userData);
 struct MultiTimerHandle {
     MultiTimer* next;
     uint64_t deadline;
-    uint32_t period;
     MultiTimerCallback_t callback;
     void* userData;
 };
 
+/**
+ * @brief Platform ticks function.
+ * 
+ * @param ticksFunc ticks function.
+ * @return int 0 on success, -1 on error.
+ */
 int MultiTimerInstall(PlatformTicksFunction_t ticksFunc);
 
-int MultiTimerInit(MultiTimer* timer, uint32_t period, MultiTimerCallback_t cb, void* userData);
-
-int MultiTimerStart(MultiTimer* timer, uint32_t startTime);
-
+/**
+ * @brief Start the timer work, add the handle into work list.
+ * 
+ * @param timer target handle strcut.
+ * @param timing Set the start time.
+ * @param callback deadline callback.
+ * @param userData user data.
+ * @return int 0: success, -1: fail.
+ */
+int MultiTimerStart(MultiTimer* timer, uint32_t timing, MultiTimerCallback_t callback, void* userData);
+
+/**
+ * @brief Stop the timer work, remove the handle off work list.
+ * 
+ * @param timer target handle strcut.
+ * @return int 0: success, -1: fail.
+ */
 int MultiTimerStop(MultiTimer* timer);
 
-void MultiTimerYield(void);
+/**
+ * @brief Check the timer expried and call callback.
+ * 
+ * @return int The next timer expires.
+ */
+int MultiTimerYield(void);
 
 #ifdef __cplusplus
 } 
diff --git a/examples/main.c b/examples/main.c
deleted file mode 100755
index e5a7c03..0000000
--- a/examples/main.c
+++ /dev/null
@@ -1,34 +0,0 @@
-#include "multi_timer.h"
-
-struct Timer timer1;
-struct Timer timer2;
-
-void timer1_callback(void *arg)
-{
-    printf("timer1 timeout! arg: %p\r\n", arg);
-}
-
-void timer2_callback(void *arg)
-{
-    printf("timer2 timeout! arg: %p\r\n", arg);
-}
-
-int main(void)
-{
-	timer_init(&timer1, timer1_callback, 1000, 1000, NULL); //1s loop
-	timer_start(&timer1);
-	
-	timer_init(&timer2, timer2_callback, 50, 0, NULL); //50ms delay
-	timer_start(&timer2);
-	
-	while(1) {	    
-	    timer_loop();
-	}
-
-    return 0;
-}
-
-void HAL_SYSTICK_Callback(void)
-{
-    timer_ticks(); //1ms ticks
-}
\ No newline at end of file
diff --git a/examples/test_linux.c b/examples/test_linux.c
index d9618e3..30ff5ad 100755
--- a/examples/test_linux.c
+++ b/examples/test_linux.c
@@ -1,92 +1,45 @@
 #include <stdio.h>
-#include <signal.h>
 #include <sys/time.h>
 #include <time.h>
-#include <stdarg.h>
-#include <string.h>
+#include "../MultiTimer.h"
 
-#include "../multi_timer.h"
+MultiTimer timer1;
+MultiTimer timer2;
+MultiTimer timer3;
 
-#define LOG_TIMESTAMP_FORMAT    "[%Y-%m-%d %H:%M:%S]"
-#define LOG_TIMESTAMP_LEN       21
-#define MS_TIMESTAMP_LEN        5
-
-int32_t printf_timestamp(const char *msg, ...)
+uint64_t PlatformTicksGetFunc(void)
 {
-    char content[1024] = {0};
-    time_t  time_write;
-    struct tm tm_Log;
-    struct timeval t; 
-    uint32_t len = 0;
-    va_list vl_list;
-
-    time_write = time(NULL);
-    localtime_r(&time_write, &tm_Log);
-    strftime((char *)&content[len], sizeof(content) - len - 1, LOG_TIMESTAMP_FORMAT, &tm_Log);
-    len = strlen(&content[len]);
-
-    /* .msec] */
-    gettimeofday(&t, NULL);
-    len--; // min a ']' char           
-    snprintf((char*)&content[len], sizeof(content) - len, ".%03d]", (int)(t.tv_usec / 1000));        
-    len += MS_TIMESTAMP_LEN; 
-
-    va_start(vl_list, msg);
-    vsnprintf((char *)&content[len], sizeof(content) - len - 1, (const char *)msg, vl_list);
-    va_end(vl_list);
-
-    printf("%s", content);
-
-    return 0;
+    struct timespec current_time;
+    clock_gettime(CLOCK_MONOTONIC, &current_time);
+    return (uint64_t)((current_time.tv_sec * 1000) + (current_time.tv_nsec / 1000000));
 }
 
-void signalHandler(int signo)
+void exampleTimer1Callback(MultiTimer* timer, void *userData)
 {
-    switch(signo)
-    {
-        case SIGALRM:
-            timer_ticks();
-            //printf_timestamp("Caught the SIGALRM signal every 1ms !\n");
-            break;
-    }
+    printf("[T:%012ld] Timer:%p callback-> %s.\r\n", PlatformTicksGetFunc(), timer, (char*)userData);
+    MultiTimerStart(timer, 1000, exampleTimer1Callback, userData);
 }
 
-struct Timer timer1;
-struct Timer timer2;
-
-void timer1_callback(void *arg)
+void exampleTimer2Callback(MultiTimer* timer, void *userData)
 {
-    printf_timestamp("timer1 timeout! arg: %p\r\n", arg);
+    printf("[T:%012ld] Timer:%p callback-> %s.\r\n", PlatformTicksGetFunc(), timer, (char*)userData);
 }
 
-void timer2_callback(void *arg)
+void exampleTimer3Callback(MultiTimer* timer, void *userData)
 {
-    printf_timestamp("timer2 timeout! arg: %p\r\n", arg);
+    printf("[T:%012ld] Timer:%p callback-> %s.\r\n", PlatformTicksGetFunc(), timer, (char*)userData);
+    MultiTimerStart(timer, 4567, exampleTimer3Callback, userData);
 }
 
-int main(void)
+int main(int argc, char *argv[])
 {
-    printf_timestamp("%s start ...\r\n", __func__);
-
-    signal(SIGALRM, signalHandler);
-
-    struct itimerval new_value, old_value;
-    new_value.it_value.tv_sec     = 0; // should be 0x00 !!!
-    new_value.it_value.tv_usec    = 1; // non-zero is OK !!!
-    new_value.it_interval.tv_sec  = 0;
-    new_value.it_interval.tv_usec = 1000 * CFG_TIMER_1_TICK_N_MS; // 1ms
-    setitimer(ITIMER_REAL, &new_value, &old_value);
+    MultiTimerInstall(PlatformTicksGetFunc);
 
-    timer_init(&timer1, timer1_callback, 4000, 1000, &timer1);  // start timer after 4s
-    timer_start(&timer1);
+    MultiTimerStart(&timer1, 1000, exampleTimer1Callback, "1000ms CYCLE timer");
+    MultiTimerStart(&timer2, 5000, exampleTimer2Callback, "5000ms ONCE timer");
+    MultiTimerStart(&timer3, 3456, exampleTimer3Callback, "3456ms delay start, 4567ms CYCLE timer");
 
-    timer_init(&timer2, timer2_callback, 0, 5000, &timer2); // start timer right now
-    timer_start(&timer2);
-
-    while(1) {
-        /* Maybe some sleep time is needed to avoid running CPU all the time. */
-        timer_loop();
+    while (1) {
+        MultiTimerYield();
     }
-
-    return 0;
-}
+}
\ No newline at end of file