nordic官方歷程自帶了FreeRTOS，移植FreeRTOS參考：https://www.cnblogs.com/zy-slient/archive/2019/03/21/10569464.html
在此感謝此博主...
移植FreeRTOS後，實測電流偏大，ma級別，而裸機情況下，低功耗模式爲3ua（最小系統電路情況下）。
查閱FreeRTOSConfig.h文件，發現使用的爲RTC時鐘，與裸機一致，如下代碼：
/*-----------------------------------------------------------
* Possible configurations for system timer
*/
#define FREERTOS_USE_RTC 0 /**< Use real time clock for the system */
#define FREERTOS_USE_SYSTICK 1 /**< Use SysTick timer for system */
/*-----------------------------------------------------------
* Application specific definitions.
*
* These definitions should be adjusted for your particular hardware and
* application requirements.
*
* THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
* FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
*
* See http://www.freertos.org/a00110.html.
*----------------------------------------------------------*/
#define configTICK_SOURCE FREERTOS_USE_RTC
進一步調試得知：FreeRTOS使用vPortSuppressTicksAndSleep進入低功耗模式，進入低功耗模式需進行如下設置：
// 此處官方模式爲 #if 0 ，設置爲1後，實測功耗與裸機下一致
#if 1 // With FreeRTOS sd_app_evt_wait increases power consumption with FreeRTOS compared to _WFE (NRFFOSDK-11174)
#ifdef SOFTDEVICE_PRESENT
if (nrf_sdh_is_enabled())
{
uint32_t err_code = sd_app_evt_wait();
APP_ERROR_CHECK(err_code);
}
else
#endif