CC2540/2541 : Change Advertising Data And Scan Response Without Rebooting

    From my previous article , I mention a method to change advertise data and scan response data by reboot. It is work, but it is not suit for change these 2 data frequently.

   In here, I note a way to change those WITHOUT rebooting. But the way needs to modify BLE stack code of Texas instrument. It may cause side effect which I do not know yet.

  
Step 0.
   Copy your SimpleBLEPeripheral folder in BLE stack to be SimpleBLEPeripheral_ChangeRSP.

Step 1.

 Move to the file simpleBLEPeripheral.c, Add calling the function RegisterForKeys in the beginning of SimpleBLEPeripheral_Init:

void SimpleBLEPeripheral_Init( uint8 task_id )
{
  simpleBLEPeripheral_TaskID = task_id;

#ifdef HAL_KEY  
   RegisterForKeys( task_id );
#endif

  Remove the preprocessor for CC2540_MINIK, about line 229

//#if defined( CC2540_MINIDK )
static void simpleBLEPeripheral_HandleKeys( uint8 shift, uint8 keys );
//#endif

And line 527:

static void simpleBLEPeripheral_ProcessOSALMsg( osal_event_hdr_t *pMsg )
{
  switch ( pMsg->event )
  {
 // #if defined( CC2540_MINIDK )
    case KEY_CHANGE:
      simpleBLEPeripheral_HandleKeys( ((keyChange_t *)pMsg)->state, ((keyChange_t *)pMsg)->keys );
      break;
 // #endif // #if defined( CC2540_MINIDK )

Obviously, I will re-implement the function

static void simpleBLEPeripheral_HandleKeys( uint8 shift, uint8 keys )

To trigger advertise data and scan response data changing.

The function simpleBLEPeripheral_HandleKeys I implemented as :

#include "string.h"
#include "stdio.h" 

void SetRspData(uint8 *pName, uint16 nameLen, 
                uint8 *pRspData, uint16 *pScanRspDataSize)
{       

  if(nameLen  > 31 - (2 + (5 + 1) + (1 + 2)) )
    nameLen =  31 - (2 + (5 + 1) + (1 + 2));
    
  pRspData[0] = nameLen + 1;
  pRspData[1] = GAP_ADTYPE_LOCAL_NAME_COMPLETE;
  memcpy(&pRspData[2], pName, nameLen); 
 
  int16  i;
  
  i = nameLen + 2; 
  pRspData[i++] = 0x05;
  pRspData[i++] = GAP_ADTYPE_SLAVE_CONN_INTERVAL_RANGE;
  pRspData[i++] = LO_UINT16( DEFAULT_DESIRED_MIN_CONN_INTERVAL );     
  pRspData[i++] = HI_UINT16( DEFAULT_DESIRED_MIN_CONN_INTERVAL );
  pRspData[i++] = LO_UINT16( DEFAULT_DESIRED_MAX_CONN_INTERVAL );     
  pRspData[i++] = HI_UINT16( DEFAULT_DESIRED_MAX_CONN_INTERVAL );
  
  pRspData[i++] = 0x02;
  pRspData[i++] = GAP_ADTYPE_POWER_LEVEL;
  pRspData[i++] = 0;       // 0dBm;    
  
  *pScanRspDataSize =  i;
}/*SetRspData*/

/*********************************************************************
 * @fn      simpleBLEPeripheral_HandleKeys
 *
 * @brief   Handles all key events for this device.
 *
 * @param   shift - true if in shift/alt.
 * @param   keys - bit field for key events. Valid entries:
 *                 HAL_KEY_SW_2
 *                 HAL_KEY_SW_1
 *
 * @return  none
 */


static void simpleBLEPeripheral_HandleKeys( uint8 shift, uint8 keys )
{ 
  
  /*ingnore the signal which be caused by stick back to original position*/  
  if(HAL_KEY_STATE_SHIFT == shift)  
    return ;
       
  uint8 rspData[32];                  
  uint8 buffer[20]; /*max rsp lengh be 20*/
  
  uint16 scanRspDataSize;
  
  scanRspDataSize = 0;  
  osal_memset(&rspData[0], 0, 32);   
  osal_memset(&buffer[0], 0, 20);   
  
  
  if ( HAL_KEY_UP & keys )
    sprintf((char*)&buffer[0], "%s", "SimpleBLEPeriUp");
  else if (HAL_KEY_DOWN & keys )  
    sprintf((char*)&buffer[0], "%s", "SimpleBLEPeriDown");
  else if (HAL_KEY_LEFT & keys )  
    sprintf((char*)&buffer[0], "%s", "SimpleBLEPeriLeft");
  else if (HAL_KEY_RIGHT & keys )  
    sprintf((char*)&buffer[0], "%s", "SimpleBLEPeriRight");
  else if (HAL_KEY_CENTER & keys )  
    sprintf((char*)&buffer[0], "%s", "SimpleBLEPeriCenter");
       
  
  uint8 adv_status;
  
  adv_status = FALSE;
  GAPRole_SetParameter( GAPROLE_ADVERT_ENABLED, 
                       sizeof( uint8 ), &adv_status );
  
  SetRspData((uint8*)&buffer[0], strlen((char*)&buffer[0]), 
               &rspData[0], &scanRspDataSize);                                                                  
  GAPRole_SetParameter( GAPROLE_SCAN_RSP_DATA, scanRspDataSize, &rspData[0]);  

  adv_status = TRUE;
  GAPRole_SetParameter( GAPROLE_ADVERT_ENABLED, 
                       sizeof( uint8 ), &adv_status );
  
  HalLcdWriteString( (char*)&buffer[0],  HAL_LCD_LINE_1);        
}/*simpleBLEPeripheral_HandleKeys*/

To replace the original one, about line 544.

And Add HAL_KEY=TRUE in the preprocessor define (not necessary).

    To here, you could found that string displayed in LCD would change when you nudge the joystick. But the peripheral name stills.

Step 2

  Add the line in file peripheral.c, about line  299:

 case GAPROLE_SCAN_RSP_DATA:
      if ( len <= B_MAX_ADV_LEN )
      {
        VOID osal_memset( gapRole_ScanRspData, 0, B_MAX_ADV_LEN );
        VOID osal_memcpy( gapRole_ScanRspData, pValue, len );
        gapRole_ScanRspDataLen = len;
        
        //GAIGER
        GAP_UpdateAdvertisingData(gapRole_TaskID,
                              TRUE, gapRole_AdvertDataLen, gapRole_AdvertData );
      }
      else
      {
        ret = bleInvalidRange;
      }      

  Then you would find the Scan Response Data would change as the joystick.

   Follow above suit, you could change advertise data without reboot, by modify the same file periphereral.c, about line 289:

 case GAPROLE_ADVERT_DATA:
      if ( len <= B_MAX_ADV_LEN )
      {
        VOID osal_memset( gapRole_AdvertData, 0, B_MAX_ADV_LEN );
        VOID osal_memcpy( gapRole_AdvertData, pValue, len );
        gapRole_AdvertDataLen = len;
        
        //GAIGER
        GAP_UpdateAdvertisingData(gapRole_TaskID,
                              TRUE, gapRole_AdvertDataLen, gapRole_AdvertData );
      }
      else
      {
        ret = bleInvalidRange;
      }
      break;

Note:
  The sequence of "stop advertising - set RSP DATA - start advertise" in my implement is not requisite, you could simplify it as setting RSP DATA only.

  But, when you remove those code, the status displayed in the LCD would be "Error" while you push the joystick, Though your cc254x works well.That is, the function 

if ( GAP_MakeDiscoverable( gapRole_TaskID, &params ) != SUCCESS )

returning bleAlreadyInRequestedMode(0x11) in peripheral.c about line 754.

  The "Error" is inevitable if you change advertise data dynamically, even there is "stop-set advertise data - start" sequence in code. But you could ingore it by mending the code as :

      params.channelMap = gapRole_AdvChanMap;
      params.filterPolicy = gapRole_AdvFilterPolicy;
     
      uint8 ret;
      
      ret = GAP_MakeDiscoverable( gapRole_TaskID, &params );      
       //GAIGER
      if(bleAlreadyInRequestedMode == ret)
        ret = SUCCESS;
      
      if ( ret != SUCCESS )
      {
        gapRole_state = GAPROLE_ERROR;
        
        // Notify the application with the new state change

 ( I use BLE stack 1.3.2, maybe the patch is redundant in newer version.)


 This article refer to ghostyu's cc254xek development suite :  : tutorial document level 4 : BLE actual practice , Section 10:
       Bluetooth Weather station - Based on Humidity & Temperature Sensor  SHT20 with I2C Interface (In simplified Chinese).