about nRF21540-EK

RE: about nRF21540-EK

yoyou — Thu, 02 Jun 2022 00:07:40 GMT

thanks

got it

RE: about nRF21540-EK

JONATHAN LL — Wed, 01 Jun 2022 15:20:28 GMT

[quote user="yuyou"]but, why default spi4 fem_spi okay? and 21540-EK have spi pins.[/quote]

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

RE: about nRF21540-EK

yoyou — Wed, 01 Jun 2022 00:35:07 GMT

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

RE: about nRF21540-EK

JONATHAN LL — Tue, 31 May 2022 13:21:55 GMT

Hi,

[quote user=""]above mean: don't use spi for 21540[/quote]

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

[quote user="yuyou"]

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

it is easily misunderstood.

[/quote]

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

[quote user="yuyou"]rx-en-gpios = < &arduino_header 0x9 GPIO_ACTIVE_LOW >; //P1.05[/quote]

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

RE: about nRF21540-EK

yoyou — Tue, 31 May 2022 01:10:53 GMT

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

RE: about nRF21540-EK

JONATHAN LL — Mon, 30 May 2022 11:23:18 GMT

Hi,

What example are you referencing, can you link ?

[quote user=""]above lines mean: max TX and RX power ?[/quote]

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

[quote user=""]above line is mean: pin P1.06 , only ANT1 ?[/quote]

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