Skip to main content
msingh08
Associate II
June 17, 2024
Solved

how to implement Sleep mode

  • June 17, 2024
  • 1 reply
  • 1483 views

I am using a STM32L431KCU6 microcontroller and reading data from I2C every 90ms. I would like to implement a sleep mode to achieve lower power consumption, I am using timer6 which generates an interrupt every1ms for system run time. I was thinking I can change the timer period to be 90ms prior to put the device on sleep and when TIM6 interrupt happens (wake up the processor) I can change the period to 1ms for normal operation.  is this possible? and how can I achieve this? 

I don't have any experience in using sleep mode but I have been reading similar questions and I've seen WFI coming up very frequently.  Is there any example codes available? or documentation which can assist in writing code? 

 

Thanks in advance and appreciate any help.

 

Kind Regards

Manpreet Singh

This topic has been closed for replies.
Best answer by Sarra.S

Hello @msingh08, 

Yes, you can change the timer period to 90ms before putting the device to sleep and then change it back to 1ms upon waking up, the code should look something like this: 

 __HAL_TIM_SET_AUTORELOAD(&htim6, 90000 - 1); // Set Timer6 period to 90ms
 __HAL_TIM_CLEAR_FLAG(&htim6, TIM_FLAG_UPDATE); // Clear update flag
 __HAL_TIM_ENABLE_IT(&htim6, TIM_IT_UPDATE); // Enable update interrupt
 __HAL_TIM_ENABLE(&htim6); // Start Timer6

// Enter sleep mode
// Wake up and reconfigure Timer6 for normal operation
 __HAL_TIM_SET_AUTORELOAD(&htim6, 1000 - 1); // Set Timer6 period to 1ms

 

1 reply

Sarra.SBest answer
ST Employee
August 1, 2024

Hello @msingh08, 

Yes, you can change the timer period to 90ms before putting the device to sleep and then change it back to 1ms upon waking up, the code should look something like this: 

 __HAL_TIM_SET_AUTORELOAD(&htim6, 90000 - 1); // Set Timer6 period to 90ms
 __HAL_TIM_CLEAR_FLAG(&htim6, TIM_FLAG_UPDATE); // Clear update flag
 __HAL_TIM_ENABLE_IT(&htim6, TIM_IT_UPDATE); // Enable update interrupt
 __HAL_TIM_ENABLE(&htim6); // Start Timer6

// Enter sleep mode
// Wake up and reconfigure Timer6 for normal operation
 __HAL_TIM_SET_AUTORELOAD(&htim6, 1000 - 1); // Set Timer6 period to 1ms

 

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
Terms & ConditionsAccessibility statement