about nRF21540-EK

[yoyou]

Hello,

NCS1.9.99,  vscode,  nRF5340-DK +  nRF21540-EK

ant-sel-gpios = < &arduino_header 0xa GPIO_ACTIVE_LOW >;   

above line is mean: pin P1.06 , only ANT1 ?

                                    

mode-gpios = < &arduino_header 0x8 GPIO_ACTIVE_LOW >;  //P1.04

above lines mean: max TX and RX power ?

      

above mean: don't use spi for 21540 ?

   

  

Best regards

[JONATHAN LL]

Hi,

What example are you referencing, can you link ?

above lines mean: max TX and RX power ?

Check the config descriptions here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.7.1/kconfig/search.html?q=FEM_NRF21540_&check_keywords=yes&area=default 

above line is mean: pin P1.06 , only ANT1 ?

the ANT_SEL pin can be used to select antenna pin, if pulled low = 0 then only ANT 1. If pulled high = 1, the ANT 2 is used.  

Regards,
Jonathan

[yoyou]

Hi,

thanks for reply

the example  is periodic_adv, 

            

pulled low = 0 , pulled high = 1,

why GPIO_ACTIVE_LOW=(1 << 0)=1,  GPIO_ACTIVE_HIGH=0  ?

it is easily misunderstood. 

                     

in periodic_adv (only tx data)

        tx-en-gpios = < &arduino_header 0xb GPIO_ACTIVE_HIGH >;     //P1.07

        rx-en-gpios = < &arduino_header 0x9 GPIO_ACTIVE_HIGH >;     //P1.05

preiodic_sync can recive data at 10M rang.

if change to

        tx-en-gpios = < &arduino_header 0xb GPIO_ACTIVE_HIGH >;     //P1.07

        rx-en-gpios = < &arduino_header 0x9 GPIO_ACTIVE_LOW >;     //P1.05

preiodic_sync can't recive data  at 10M rang.

     

    

Best regards

[JONATHAN LL]

Hi,

above mean: don't use spi for 21540

Yes, SPI is disabled. And we don't have any SPI divers for the nRF21540.

yoyou said:

why GPIO_ACTIVE_LOW=(1 << 0)=1,  GPIO_ACTIVE_HIGH=0  ?

it is easily misunderstood. 

Yes, it can be misunderstood, sorry for the confusion.  

yoyou said:

rx-en-gpios = < &arduino_header 0x9 GPIO_ACTIVE_LOW >;     //P1.05

This disables the RX enable option since you will now do the opposite of what you think you are doing, it is no longer enabled when you want to. You are inverting the pin state. 

Stick to how it is configured in the overlay file: sdk-nrf/nrf21540_ek.overlay at main · nrfconnect/sdk-nrf · GitHub 


Regards,
Jonathan

[yoyou]

Hi,

thanks for reply,

Yes, SPI is disabled. And we don't have any SPI divers for the nRF21540.

but, why default spi4 fem_spi okay? and 21540-EK have spi pins.

                           

rx-en-gpios = < &arduino_header 0x9 GPIO_ACTIVE_LOW >;     //P1.05

i mean, adv side only use TX, sync side  only use RX, One way communication.

why in the adv side disable RX, sync side can't recivce data?

    

Best regards

[JONATHAN LL]

yoyou said:

but, why default spi4 fem_spi okay? and 21540-EK have spi pins.

It is possible to use SPI, but we do not recommend this since it is slower then GPIO. There is also partials control over SPI. So that is a option. But we only recommend GPIO control. 

Regards,
Jonathan

[yoyou]

thanks

got it