Posted by MattReed59 on 2016-05-04 16:55

I can’t see what I’m doing wrong. The processor seems to be going to sleep, but the current remains the same.

Here is the sleep code:

~
int sleep(void)
{
    TIM_HandleTypeDef tim;
    uint32_t savedier = 0;

    // Reduce clock to 1 MHz
    SystemClock_Config_NOPLL_48M_100K(RCC_MSIRANGE_4);
    // Go to low-power run mode
    HAL_PWREx_EnableLowPowerRunMode();

    tim.Instance = TIM1;
    if (0 != (TIM1->CR1 & TIM_CR1_CEN))   // Turn timer off  This works!
    {
        ++savedier;
        HAL_TIM_Base_Stop_IT(&tim);
    }
    last_isr = 0xFF;
    wakeup_isr = 0;
    w_cnt = 0;

    // Request to enter SLEEP mode
    do
    {
        HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI);
        ++w_cnt;
    } while (0 == wakeup_isr);

    SetSysClock();
    HAL_PWREx_DisableLowPowerRunMode();
    if (0 != savedier)
        HAL_TIM_Base_Start_IT(&tim);

    return last_isr;
}
~

The system has FreeRTOS, the Hal timer is set to TIM1.
In the stm32l4xx_it.c I set last_isr to the interrupt position and wakeup_isr to 1 if this ISR is suppose to wake us up from sleep.

I do this because I can’t stop FreeRTOS’s system ticks and other service interrupts. I have created code that turned off those interrupts, but FreeRTOS would not work when I turned them back on.

But even with FreeRTOS running occationally, I should see some reduction in current consumption, but I see none. Not even a little.

I’ve been looking for manuals, but I can’t find anything that says what you should do to get it into low power, only what gets turned off and on and theory of operation.

I found out about the less than 2MHz and lower-power mode from comments in the HAL_PWR_EnterSLEEPMode routine.

I’ve done this before, on many different processors. Don’t know why I can’t get it to work here.

-Matt