CC2652P: LQI to link cost mapping

Hi Shuyang,

Your interpretation is correct, below is the nwkConvertLqiToCost function from the internal Z-Stack source code:

/*********************************************************************
 * @fn          nwkConvertLqiToCost
 *
 * @brief       Convert Link Qualiy valuel (lqi 1~255) to link cost (1~7)
 *
 * @param       lqi - link quality value
 *
 * @return      uint8_t - link cost
 */
uint8_t nwkConvertLqiToCost( uint8_t lqi )
{
  uint8_t cost;

  cost = MAX_LINK_COST ;

  if ( lqi > MIN_LQI_COST_1 )
  {
    cost = 1;
  }
  else if ( lqi > MIN_LQI_COST_3 )
  {
    cost = 3;
  }
  else if ( lqi > MIN_LQI_COST_5 )
  {
    cost = 5;
  }
  else if ( lqi == LINK_AGEOUT_COST )
  {
    cost = LINK_AGEOUT_COST;
  }

  return cost;
}

Software Development is aware that the cost mapping is outdated and needs revising, below are the currently recommended changes:

#define MIN_LQI_COST_1                64  //192
#define MIN_LQI_COST_2                32  //128
#define MIN_LQI_COST_3                16  //96
#define MIN_LQI_COST_4                12  //64
#define MIN_LQI_COST_5                8   //32
#define MIN_LQI_COST_6                4   //16
#define MIN_LQI_COST_7                1   //1
#define MIN_LQI_COST_0                0   //0

Regards,
Ryan