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2014-04-15 00:10:01 +07:00
parent beb46a2492
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 # Run Demos #

-<!-- START doctoc generated TOC please keep comment here to allow auto update -->
-<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
-**Table of Contents**
-
- [LPCXpresso](#lpcxpresso)
- [Keil](#keil)
- [IAR](#iar)
- [Configure demo](#configure-demo)
-
-<!-- END doctoc generated TOC please keep comment here to allow auto update -->
-
-For simplicity and user's convenience, there are only 2 basic application demos which are *Device* and *Host*. Each application demo has a few projects, each for its supported RTOS. For instance in the /demo/device you will find 3 projects
+For simplicity and user's convenience, there are only 2 basic application demos which are *Device* and *Host* respectively. Each application demo, however, has a few projects, each for its supported RTOS. For instance in the /demo/device you will find:

 - device\_os\_none for no RTOS
 - device\_freertos for freeRTOS
 - device\_cmsis_rtx for ARM CMSIS with RTX implemenation

+To be able to have the same application code running across RTOSes, the application make use of the "internal" **OSAL layer**. Thus this makes the application code a bit weird and over-complicated than it should be in some (many) cases. This is absolutely not necessary in product development. User can just use the native API function of supported RTOS or a state machine or blocking wait in case of none OS. For example, instead of the blinking task in application
+
+~~~{.c}
+OSAL_TASK_FUNCTION( led_blinking_task , p_task_para)
+{
+  OSAL_TASK_LOOP_BEGIN
+
+  static uint32_t led_on_mask = 0;
+
+  osal_task_delay(led_blink_interval_ms);
+
+  board_leds(led_on_mask, 1 - led_on_mask);
+  led_on_mask = 1 - led_on_mask; // toggle
+
+  OSAL_TASK_LOOP_END
+}
+~~~
+
+can be written in FreeRTOS's native API
+
+~~~{.c}
+void led_blinking_task( void * p_task_para )
+{
+  while(1)
+  {
+    static uint32_t led_on_mask = 0;
+
+    // FreeRTOS API's vTaskDelay is used in place of osal_task_delay. Note it takes input parameter in tick
+    vTaskDelay( (led_blink_interval_ms * TUSB_CFG_TICKS_HZ) / 1000);
+
+    board_leds(led_on_mask, 1 - led_on_mask);
+    led_on_mask = 1 - led_on_mask; // toggle
+  }
+}
+~~~
+
+## Prerequisites ##
+
+In order to run application demo, you would need
+
+- A [supported development board](../../boards/readme.md)
+- A supported toolchain: LPCXpresso, Keil, IAR.
+


 \subpage md_doxygen_started_device_demo
+
 \subpage md_doxygen_started_host_demo