The callbacks in esb/gazell not work?How can we run ble and gazell/esb simultaneously?

Question

Hi,I want to use my phone connect to NRF51822 by BLE, and used NRF24LE1 connect NRF51822 by GAZELL/ESB.That is to say, i want to use the device work with gazell/esb protocol and BLE alternatively! I add the function in the example(nRF51_SDK_8.1.0_b6ed55f\examples\ble_peripheral\ble_app_hids_keyboard\pca10028\s110\arm4).That is the code what i add in the example: 
 static nrf_radio_request_t m_timeslot_request;
static uint32_t m_slot_length = 10000;
static nrf_radio_signal_callback_return_param_t signal_callback_return_param;
static volatile bool m_esb_initialized = false;

#define PIPE_NUMBER 0 
#define TX_PAYLOAD_LENGTH 1 

static uint8_t my_tx_payload[TX_PAYLOAD_LENGTH]; 
static uint8_t my_rx_payload[NRF_ESB_CONST_MAX_PAYLOAD_LENGTH]; 

static void m_configure_earliest_timeslot(void)
{
	m_timeslot_request.request_type = NRF_RADIO_REQ_TYPE_EARLIEST;
	m_timeslot_request.params.earliest.hfclk = NRF_RADIO_HFCLK_CFG_DEFAULT;
	m_timeslot_request.params.earliest.priority = NRF_RADIO_PRIORITY_NORMAL;
	m_timeslot_request.params.earliest.length_us = m_slot_length;
	m_timeslot_request.params.earliest.timeout_us = 1000000;
}

static void m_configure_normal_timeslot(void)
{
	m_timeslot_request.request_type = NRF_RADIO_REQ_TYPE_NORMAL;
	m_timeslot_request.params.normal.hfclk = NRF_RADIO_HFCLK_CFG_DEFAULT;
	m_timeslot_request.params.normal.priority = NRF_RADIO_PRIORITY_NORMAL;
	m_timeslot_request.params.normal.length_us = m_slot_length;
	m_timeslot_request.params.normal.distance_us = 200000;
}

static void timeslot_on_start(void)
{
 bool res;
 signal_callback_return_param.params.request.p_next = NULL;
 signal_callback_return_param.callback_action = NRF_RADIO_SIGNAL_CALLBACK_ACTION_NONE; 
	
 if (!m_esb_initialized )
 {
 res = nrf_esb_init(NRF_ESB_MODE_PTX); 
 printf("%d
", res)
 
 nrf_esb_enable();

 (void)nrf_esb_add_packet_to_tx_fifo(PIPE_NUMBER, my_tx_payload, TX_PAYLOAD_LENGTH, NRF_ESB_PACKET_USE_ACK);

 m_esb_initialized = true;
 }
 
 NRF_TIMER0->INTENSET = TIMER_INTENSET_COMPARE0_Msk; 
 NRF_TIMER0->CC[0] = m_slot_length - 1000;
 NVIC_EnableIRQ(TIMER0_IRQn); 
}

static void m_on_multitimer(void)
{ 
 NRF_TIMER0->EVENTS_COMPARE[0] = 0;
 NRF_TIMER0->TASKS_STOP = 1;
 
 m_configure_normal_timeslot();
 signal_callback_return_param.params.request.p_next = &m_timeslot_request;
 signal_callback_return_param.callback_action = NRF_RADIO_SIGNAL_CALLBACK_ACTION_REQUEST_AND_END;	
}

void timeslot_sys_event_handler(uint32_t sys_evt)
{
 uint32_t err_code;
 
 printf("sys_evt = %d
", sys_evt);
 switch (sys_evt)
 {
 case NRF_EVT_RADIO_SIGNAL_CALLBACK_INVALID_RETURN:
 {
 
 }break;
 
 case NRF_EVT_RADIO_SESSION_IDLE:
 {
 
 }break;

 case NRF_EVT_RADIO_SESSION_CLOSED:
 {
 
 }break;

 case NRF_EVT_RADIO_BLOCKED:
 case NRF_EVT_RADIO_CANCELED:
 {
 m_configure_earliest_timeslot();
 err_code = sd_radio_request(&m_timeslot_request);
 APP_ERROR_CHECK(err_code);
 }break;

 default:break;
	}
}

nrf_radio_signal_callback_return_param_t * m_radio_callback(uint8_t signal_type)
{ 
	printf("signal_type = %d
", signal_type);
 switch(signal_type)
 {
 case NRF_RADIO_CALLBACK_SIGNAL_TYPE_START:
 {
 timeslot_on_start();
 }break;

 case NRF_RADIO_CALLBACK_SIGNAL_TYPE_TIMER0:
 {
 m_on_multitimer();
 }break;

 case NRF_RADIO_CALLBACK_SIGNAL_TYPE_RADIO:
 {
 signal_callback_return_param.params.request.p_next = NULL;
 signal_callback_return_param.callback_action = NRF_RADIO_SIGNAL_CALLBACK_ACTION_NONE;
 }break;
 
 default:break;
 }
 
 return (&signal_callback_return_param);
}

uint32_t radio_timeslots_start(void)
{
 uint32_t err_code;
 
 err_code = sd_radio_session_open(m_radio_callback);
 
 if(err_code != NRF_SUCCESS)
 {
 return err_code;
 }
 
 m_configure_earliest_timeslot();
 err_code = sd_radio_request(&m_timeslot_request);
 
 if(err_code != NRF_SUCCESS)
 {
 (void)sd_radio_session_close();
 
 return err_code;
 }

 return NRF_SUCCESS;
}

void nrf_esb_tx_success(uint32_t tx_pipe, int32_t rssi)
{
 static uint32_t success_times = 0;
 
 success_times++;
 printf("%d %d
", success_times, rssi);
 
 my_tx_payload[0]++;
 (void)nrf_esb_add_packet_to_tx_fifo(PIPE_NUMBER, my_tx_payload, TX_PAYLOAD_LENGTH, NRF_ESB_PACKET_USE_ACK); 
}

void nrf_esb_tx_failed(uint32_t tx_pipe)
{
 static uint32_t failed_times = 0;
 
 failed_times++;
 printf("%d
", failed_times); 
 
 my_tx_payload[0]++;
 (void)nrf_esb_add_packet_to_tx_fifo(PIPE_NUMBER, my_tx_payload, TX_PAYLOAD_LENGTH, NRF_ESB_PACKET_USE_ACK); 
}

void nrf_esb_rx_data_ready(uint32_t rx_pipe, int32_t rssi)
{
 uint32_t my_rx_payload_length;
 
 (void)nrf_esb_fetch_packet_from_rx_fifo(PIPE_NUMBER, my_rx_payload, &my_rx_payload_length);
 if (my_rx_payload_length > 0)
 {
 printf("%d %d
", rssi, my_rx_payload[0]);
 } 
}

void nrf_esb_disabled(void)
{
 printf("disable
");
}
 
 But do not printf anything about the four callback functions. The printf as follows: 
 signal_type = 0
Start
signal_type = 1
sys_evt = 2
signal_type = 0
signal_type = 1
signal_type = 0
signal_type = 1
signal_type = 0
signal_type = 1
sys_evt = 4
signal_type = 0
signal_type = 1
signal_type = 0
signal_type = 1
signal_type = 0
signal_type = 1
signal_type = 0
signal_type = 1
signal_type = 0
 
 So the four callback functions not be executed, why? What's wrong with the project?Thank you in advance!