PA + LNA with BLE and Zigbee at the same time

[sjf]

Hi,

We have been working with a coordinator and a router device based on nRF52840 with nRF5_SDK_for_Thread_and_Zigbee_v4.0.0_dc7186b

Both devices are Zigbee 3.0 and implement Install Codes.

On the Coordinator we have Zigbee and BLE turned on at the same time on a Fanstel BT840X with integrated PA/LNA

We tried several things:

1.When running this code, BLE seems to work but Zigbee does not seem to send Link Status messages among others

ret_code_t pa_lna_init(uint32_t gpio_pa_pin, uint32_t gpio_lna_pin)
{
    ble_opt_t opt;
    uint32_t gpiote_ch = NULL;
    ret_code_t err_code;        

    nrf_gpio_cfg_output(APP_CPS_PIN);
    nrf_gpio_cfg_output(APP_CHL_PIN);
    nrf_gpio_pin_set(APP_CHL_PIN);	
    nrf_gpio_pin_clear(APP_CPS_PIN); //enable
    //nrf_gpio_pin_set(APP_CPS_PIN); //bypass
    nrf_gpio_cfg_output(APP_PA_PIN);
    nrf_gpio_pin_clear(APP_PA_PIN); //
    nrf_gpio_cfg_output(APP_LNA_PIN);
    nrf_gpio_pin_clear(APP_LNA_PIN); //

    memset(&opt, 0, sizeof(ble_opt_t));
    
    if (!nrf_drv_gpiote_is_init())
    {
      err_code = nrf_drv_gpiote_init();
      if(err_code != NRF_ERROR_INVALID_STATE)
          APP_ERROR_CHECK(err_code);
    }
    
    err_code = nrf_drv_ppi_init();
    if(err_code != NRF_ERROR_MODULE_ALREADY_INITIALIZED)
        APP_ERROR_CHECK(err_code);
    
    nrf_ppi_channel_t ppi_set_ch;
    nrf_ppi_channel_t ppi_clr_ch;
    
    err_code = nrf_drv_ppi_channel_alloc(&ppi_set_ch);
    APP_ERROR_CHECK(err_code);
    
    err_code = nrf_drv_ppi_channel_alloc(&ppi_clr_ch);
    APP_ERROR_CHECK(err_code);

    nrf_drv_gpiote_out_config_t config = GPIOTE_CONFIG_OUT_TASK_TOGGLE(false);
    
    if((gpio_pa_pin == NULL) && (gpio_lna_pin == NULL))
    {
        err_code = NRF_ERROR_INVALID_PARAM;
        APP_ERROR_CHECK(err_code);
    }    

    if(gpio_pa_pin != NULL)
    {
        if(gpiote_ch == NULL)
        {
            // nrf_drv_gpiote_out_uninit(gpio_pa_pin);
            err_code = nrf_drv_gpiote_out_init(gpio_pa_pin, &config);
            APP_ERROR_CHECK(err_code);
            
            gpiote_ch = nrf_drv_gpiote_out_task_addr_get(gpio_pa_pin); 
        }
        
        // PA config
        opt.common_opt.pa_lna.pa_cfg.active_high = 1;   // Set the pin to be active high
        opt.common_opt.pa_lna.pa_cfg.enable      = 1;   // Enable toggling
        opt.common_opt.pa_lna.pa_cfg.gpio_pin    = gpio_pa_pin; // The GPIO pin to toggle tx  
    }
    
    if(gpio_lna_pin != NULL)
    {
        if(gpiote_ch == NULL)
        {
            // nrf_drv_gpiote_out_uninit(gpio_lna_pin);
            err_code = nrf_drv_gpiote_out_init(gpio_lna_pin, &config);
            APP_ERROR_CHECK(err_code);        
            
            gpiote_ch = nrf_drv_gpiote_out_task_addr_get(gpio_lna_pin); 
        }
        
        // LNA config
        opt.common_opt.pa_lna.lna_cfg.active_high  = 1; // Set the pin to be active high
        opt.common_opt.pa_lna.lna_cfg.enable       = 1; // Enable toggling
        opt.common_opt.pa_lna.lna_cfg.gpio_pin     = gpio_lna_pin;  // The GPIO pin to toggle rx
    }

    // Common PA/LNA config
    opt.common_opt.pa_lna.gpiote_ch_id  = (gpiote_ch - NRF_GPIOTE_BASE) >> 2;   // GPIOTE channel used for radio pin toggling
    opt.common_opt.pa_lna.ppi_ch_id_clr = ppi_clr_ch;   // PPI channel used for radio pin clearing
    opt.common_opt.pa_lna.ppi_ch_id_set = ppi_set_ch;   // PPI channel used for radio pin setting
    
    err_code = sd_ble_opt_set(BLE_COMMON_OPT_PA_LNA, &opt);
    // APP_ERROR_CHECK(err_code);    

    return err_code;
}

2. When setting at sdk_config.h FEM_CONTROL_DEFAULT_ENABLE to 1 (and other FEM_CONTROL_DEFAULT_XXX for pins), BLE stops working...

So, we would like to know which is the right approach to get Zigbee and BLE working at the same time with PA/LNA

Regards,

Santiago

[Edvin]

Hello,

Are you sure pa_lna is related to this at all? Did everything work as expected before you enabled pa lna? Did the Zigbee work as expected? 

 

2. When setting at sdk_config.h FEM_CONTROL_DEFAULT_ENABLE to 1 (and other FEM_CONTROL_DEFAULT_XXX for pins), BLE stops working...

 What do you mean by that? What happens when it stops working? Do you get an application/softdevice assert?

[sjf]

Hi Edvin,

Sorry for the late response.

Yes, without enabling the PA/LNA everything works as expected.

When FEM_CONTROL_DEFAULT_ENABLE is enabled, BLE connections are rejected from the NRF Toolbox App...

No assert from App/SD

Is there any proper example or recommendation for enabling PA/LNA on BLE and Zigbee at the same time?

Regards,

Santiago

 

[Edvin]

What do you mean by this? Are there one retransmission? Many? On every packet? Or only occasionally?

[sjf]

Hi Edvin,

By setting NRF_FEM_PA_TIME_IN_ADVANCE_US and NRF_FEM_LNA_TIME_IN_ADVANCE_US to their default values (23 and 5 us) there is nothing logged into Wireshark.

When tried some other values (i.e. 40us for both values) we can see that data is sent from the device and sometimes received, but there are several retransmissions from other devices when sending reports to this device (on every packet, not occasionally).

Regards

[Edvin]

How many retransmissions are we talking about? Are you sure that what you are seeing is not just the packet hopping through the network? Check the source and destination address on the bottom layer. of the message. Can you send a sniffer trace showing this?

BR,

Edvin

[sjf]

Hi Edvin,

Yes, we are testing this with an end device and a coordinator only.

The Data Request, for example, is sent many times until get an ack.

[Edvin]

Can you share a sniffer trace showing this, please?

[sjf]

Hi Edvin,

Based on results, we decided to remove PA/LNA from our project

Regards