Hi,
I'm trying to figure out what could make the current consumption difference between your blinky example with freertos and with the timer example ?
Here is my configuration :
- Board : pca10056
- Low voltage mode, with REG1 as DC/DC and REG0 as LDO
- Deep Sleep mode enabled in the timer example
I disabled leds control (so it doesn't blink any leds) to only monitor the mcu consumption. Here are the 2 code snippets :
With Freertos :
TaskHandle_t led_toggle_task_handle; /**< Reference to LED0 toggling FreeRTOS task. */
/**@brief LED0 task entry function.
*
* @param[in] pvParameter Pointer that will be used as the parameter for the task.
*/
static void led_toggle_task_function (void * pvParameter)
{
UNUSED_PARAMETER(pvParameter);
while (true)
{
/* Delay a task for a given number of ticks */
vTaskDelay(TASK_DELAY);
/* Tasks must be implemented to never return... */
}
}
int main(void)
{
ret_code_t err_code;
NRF_POWER->DCDCEN = 0x01; // enable REG0 DC/DC converter
/* Initialize clock driver for better time accuracy in FREERTOS */
err_code = nrf_drv_clock_init();
APP_ERROR_CHECK(err_code);
/* Configure LED-pins as outputs */
bsp_board_init(BSP_INIT_LEDS);
/* Create task for LED0 blinking with priority set to 2 */
UNUSED_VARIABLE(xTaskCreate(led_toggle_task_function, "LED0", configMINIMAL_STACK_SIZE + 200, NULL, 2, &led_toggle_task_handle));
/* Activate deep sleep mode */
SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
/* Start FreeRTOS scheduler. */
vTaskStartScheduler();
while (true)
{
/* FreeRTOS should not be here... FreeRTOS goes back to the start of stack
* in vTaskStartScheduler function. */
}
}
With Timer :
const nrf_drv_timer_t TIMER_LED = NRF_DRV_TIMER_INSTANCE(0);
volatile bool timer_flag = false;
/**
* @brief Handler for timer events.
*/
void timer_led_event_handler(nrf_timer_event_t event_type, void* p_context)
{
timer_flag = true;
}
void sample_loop()
{
// Wait for the timer to expire
while(timer_flag == false)
{
__WFI(); // go to sleep mode
}
timer_flag = false;// reset timer flag
}
/**
* @brief Function for main application entry.
*/
int main(void)
{
const uint32_t time_ms = 500; //Time(in miliseconds) between consecutive compare events.
uint32_t time_ticks;
uint32_t err_code = NRF_SUCCESS;
NRF_POWER->DCDCEN = 0x01; // Enable REG1 DC/DC
NRF_POWER->TASKS_CONSTLAT = 0x01; // Enable constant latency low power mode
SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk; // activate deep sleep mode
//Configure all leds on board.
bsp_board_init(BSP_INIT_LEDS);
//Configure TIMER_LED for generating simple light effect - leds on board will invert his state one after the other.
nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
err_code = nrf_drv_timer_init(&TIMER_LED, &timer_cfg, timer_led_event_handler);
APP_ERROR_CHECK(err_code);
time_ticks = nrf_drv_timer_ms_to_ticks(&TIMER_LED, time_ms);
nrf_drv_timer_extended_compare(
&TIMER_LED, NRF_TIMER_CC_CHANNEL0, time_ticks, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
nrf_drv_timer_enable(&TIMER_LED);
while (1)
{
sample_loop();
}
}
The current consumption is approximately 0.5mA higher with the use of timer compared to freertos. Can you explain to me where does it come from please ?
Our device will be battery powered so it's pretty important to know.. We thought that getting rid of Freertos would improve power consumption...
Best regards,
Hugo
