Register RPD in NRF24LE1

[Raul]

Im try to read the RPD register, but always get the same value RPD=0

uint8_t channel=0;
int index;
hal_nrf_set_operation_mode(HAL_NRF_PRX);
hal_nrf_set_power_mode(HAL_NRF_PWR_UP);
CE_HIGH();
for( index = 0; index<126; index++)´
{
   hal_nrf_set_rf_channel(channel);
   if(hal_nrf_get_carrier_detect())
      {putstring("Channel Busy");}
    else { putstring("Channel Free");  }
    channel++;
 }

The output is all channels are free. How could I can read correctly the RPD?

Regards¡

[ovrebekk]

You can't change the RF channel without disabling the receiver first with CE_LOW();
Could you try to change that and see if it works better?
Best regards

[Raul]

Thank for suppor me. Im try to disable the receiver as you said, but the result is the same. Some idea about it? Regards

[ovrebekk]

It takes 130us for the receiver to turn on. Do you have some delay after setting CE_HIGH() before you try to read the RPD register?

[Raul]

I have tested with a 1000mseg of delay, now every time I run the loop the response is diferent; some times show some occupied channels, other times all channels are free, but never repeat the same occupied channels. Is reliable use the RPD register to determine occupied channels? Thahk¡

[ovrebekk]

You would probably have to do a long series of measurements, and add some filtering to your data, to get a more realistic estimate of channel occupancy. The problem is that interferers in the area like WiFi or Bluetooth devices might send data at a very random and unpredictable rate, making it hard to predict which channels might be occupied in the future.

Best regards