It has been some time since I try to bring FreeRTOS + Stop mode on STM32L072 board. It's good to have the powerful os API and low current consumption at the same time. But ST seems not providing a complete and ready solution in CubeMX. So it do take me several days to peek through the code , fortunately with google articles, finally got a solution.

Steps

CubeMX code generation

The default low power mode is Sleep Mode. We will customize CubeMX settings.

"Pinout & Configuration"

RCC      - Enable HSE & LSE
SYS       -  Enable Debug Serial Wire
               - TimeBase source [ TIM2 ]
LPTIM1 - Mode [counts internal clock events]
              - Enable NVIC 
RTC       - Activate Clock Source
Middleware - FreeRTOS enable

"Clock Configuration"

LPTIMCLK  -  Select LSE

Codes to add

__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime ){

}

Cube_FW_L0_V1.11.2 reference source code

NUCLEO-L053R8/Applications/FreeRTOS/FreeRTOS_LowPower_LPTIM

Here we will use LPTIM as tick timer clock source during STOP mode , as TIM2 will stop functioning then.

Test Environment

VCC : 3 V

Without low power mode

current consumption = 8.3 mA

With low power sleep mode

current consumption =