nRF24L01+ RF_CH bits



  • I am confused by the channel bits (RF_CH) in register 0x05.
    why is there a '1' in bit 1. I guess it can't be used and so the range is
    00000010   - 2400MHz
    00000011  -  2401MHz
    00000110 (6) - 2406MHz ??????
    00000111 (7)

    The datasheet says the freq range is 2400 to 2525MHz but it also says Freq = 2400 + RF_CH MHz
    Which therefore makes the first channel (00000010) 2402MHz



  • RF_CH bits are used to select channel. Channel number and frequence calculated like this: F = 2400 + RF_CH.

    And some usefull table.

    alt text


  • Mod

    @ul7aajr which part of the world is that tabe for?



  • I suppose for Canada. Anyway, is better to avoid to use 0-82 channels. It's really noisy.



  • EU regulation is as following:

    Frequency band Category of short-range devices
    2 400 -2 483,5 MHz Non-specific short-range devices [3]
    2 400 -2 483,5 MHz Radio determination devices [9]
    2 400 -2 483,5 MHz Wideband data transmission devices [16]
    2 446 -2 454 MHz Radio Frequency Identification (RFID) devices [12]
    2 483,5 -2 500 MHz Active medical implant devices [1]
    2 483,5 -2 500 MHz Medical data acquisition [20]
    2 483,5 -2 500 MHz Medical data acquisition [20]

    Source and details here.
    It is very clear that only 2 400 -2 483,5 MHz can be used for these kind of sensors. Higher frequencies are used by medical devices.


  • Mod

    @bakcsa thanks for the nice source.

    Your observation is in line with the note in MySensors documentation that says the same channels are allowed in Germany.


 

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