The esb keeps returning ack

[kenyon]

example:ble_app_uart+ esb_timeslot
SDK17.1

Hi
Recently our product (PRX) received poor esb communication. I caught through sniffer that when PTX sends a message, our device keeps returning ack, which is why.


The following code deals with the initialization of the esb.

/** @brief Default legacy radio parameters. Identical to the nRF24Lxx defaults. */
#define NRF_ESB_LEGACY_CONFIG  {.protocol               = NRF_ESB_PROTOCOL_ESB,             \
                                .mode                   = NRF_ESB_MODE_PTX,                 \
                                .event_handler          = 0,                                \
                                .bitrate                = NRF_ESB_BITRATE_2MBPS,            \
                                .crc                    = NRF_ESB_CRC_8BIT,                 \
                                .tx_output_power        = NRF_ESB_TX_POWER_0DBM,            \
                                .retransmit_delay       = 300,                              \
                                .retransmit_count       = 1,                                \
                                .tx_mode                = NRF_ESB_TXMODE_AUTO,              \
                                .radio_irq_priority     = 1,                                \
                                .event_irq_priority     = 2,                                \
                                .payload_length         = 32,                               \
                                .selective_auto_ack     = false                             \
}

static nrf_esb_config_t             nrf_esb_config = NRF_ESB_LEGACY_CONFIG;  

uint32_t esb_timeslot_init(void)
{
	void nrf_esb_event_handler(nrf_esb_evt_t const * p_event);
   // m_evt_handler = evt_handler;
	
    nrf_esb_config.protocol                 = NRF_ESB_PROTOCOL_ESB_DPL;
    nrf_esb_config.selective_auto_ack       = 0;
	//nrf_esb_config.retransmit_delay         = 250;
	//nrf_esb_config.payload_length           = 8;//6;
    nrf_esb_config.bitrate                  = NRF_ESB_BITRATE_2MBPS;
    nrf_esb_config.mode                     = NRF_ESB_MODE_PRX;
    nrf_esb_config.event_handler            = nrf_esb_event_handler;
    nrf_esb_config.crc                      = NRF_ESB_CRC_16BIT;
    nrf_esb_config.radio_irq_priority       = 0;
    nrf_esb_config.tx_output_power          = NRF_ESB_TX_POWER_4DBM;

    // Using three avilable interrupt handlers for interrupt level management
    // These can be any available IRQ as we're not using any of the hardware,
    // simply triggering them through software
    NVIC_ClearPendingIRQ(TIMESLOT_END_IRQn);
    NVIC_SetPriority(TIMESLOT_END_IRQn, 2);
    NVIC_EnableIRQ(TIMESLOT_END_IRQn);

    NVIC_ClearPendingIRQ(TIMESLOT_BEGIN_IRQn);
    NVIC_SetPriority(TIMESLOT_BEGIN_IRQn, 2);
    NVIC_EnableIRQ(TIMESLOT_BEGIN_IRQn);

    return NRF_SUCCESS;
}



uint32_t esb_start_PRX(bool selective_auto_ack) { // need a return value due to "VERIFY_SUCCESS" did
    uint32_t err_code;

    if (m_state == LL_ESB_STATE_IDLE) {
        #if 1 // suggestion from Nordic forum to fix "wrong pattern": power cycle RADIO before init
            NRF_RADIO->POWER = 0;
            NRF_RADIO->POWER;
            NRF_RADIO->POWER = 1;
        #endif
        nrf_esb_config.mode               = NRF_ESB_MODE_PRX;
        nrf_esb_config.selective_auto_ack = false;
        err_code = nrf_esb_init(&nrf_esb_config); APP_ERROR_CHECK(err_code);
        LL_ESB__set_address();
        err_code = nrf_esb_set_prefixes(addr_prefix, 8); APP_ERROR_CHECK(err_code);
    }
    nrf_esb_set_rf_channel(55);

    CRITICAL_REGION_ENTER();
    if (m_state != LL_ESB_STATE_RX)
    {
        /* No packets in the Tx FIFO: start reception */
        err_code = nrf_esb_start_rx();
        APP_ERROR_CHECK(err_code);
        m_state = LL_ESB_STATE_RX;
    }
    CRITICAL_REGION_EXIT();
    return NRF_SUCCESS;
}

Best regard
Kenyon