finish practical work 2

Time between sending and receiving event :
- Waveforms : 19us
- TraceAnalyzer : 18us

main.c

@@ -51,7 +51,8 @@ void EXTI2_IRQHandler(void)
 void HAL_GPIO_EXTI_Callback(uint16_t GPIO_PIN)
 {
 	//button interrupt
-	HAL_GPIO_TogglePin(GPIOF, GPIO_PIN_9);
+	HAL_GPIO_WritePin(GPIOF, GPIO_PIN_9, 1);
+	osEventFlagsSet(evt_id, 0x1U);
 }
  
 
@@ -62,8 +63,8 @@ __NO_RETURN static void taskCounter(void *argument) {
 
 	
 	for (;;) {
-		osEventFlagsWait(evt_id);
-		osEventFlagsClear(evt_id, );
+		osEventFlagsWait(evt_id, 0x1U, osFlagsWaitAny, osWaitForever);
+		HAL_GPIO_WritePin(GPIOF, GPIO_PIN_9, 0);
 	}
 }