RE: How to use _WFI and WFE to enter idle mode

Susheel Nuguru — Wed, 04 May 2016 08:00:40 GMT

You still have a race condition when you use bPoweSaving with __WFI. Please read Anders comment here Because you are using WFI and the flag in the same context, I think it is ok but i see something wrong in you code.

I also do not understand your while state, since it will not allow the bPoweSaving to be set to true ever as while loop will never end

int main(void)
{
  BSP_Init();

  static bool bPoweSaving = false;


    int16_t         XYZ_Data[3]={0};

    uint8_t reg = 0;
    ret_code_t err_code;
    static int i = 0;


    while(true)
    {

        /* Start transaction with a slave with the specified address. */
     if( bPoweSaving)
     {
       bPoweSaving = false;
       __WFI();

     }
     else
     {
       __WFE();
     }

     err_code = LIS3DH_ReadOutZYX(XYZ_Data);  
     
     if (i++ > 100)
     {
       i = 0;  
       bPoweSaving = true;
     }
    }

}

This above code will first sleep on WFI on every 100th reads and sleeps on WFE before 0 to 99 reads.