how to configure and work with nrf21540 with a pcb

[ziv123]

Hello Nordic

I am working with nrf52840 and nrf52832 on pcbs, i want to use the nrf21540 with my pcbs to extend the strength of transmission.

I have read this data sheet : https://infocenter.nordicsemi.com/pdf/nRF21540_PS_v1.0.pdf

And saw the webinar on this page: https://www.nordicsemi.com/Products/Development-hardware/nRF21540-DB

I work with ncs1.9.2

I have some questions:

1. Is there an example using the nrf21 on some other board that I can look into ? 
2. Can I program and work with the nrf21540 only with GPIOs ? If so, how can I configure tx power to different values ? 
3. When wanting to transmit, or receive, can’t we go from PD->TRX, do we have to PD->PG->TRX (that takes up to 28 microsec if i am correct ) ?
4. If we need to switch from TX to RX do we need to switch TRX(TX)->PG->TRX(RX) and vice versa ? because this means transiting between receiving and transmitting taks up to 13.5 microsec, am I correct ? 

I refer to this table:

1. If I want the nrf21540 to receive and transceive as the nrf52840 works, do I need to keep programming it or can it be configured somehow by UICR to certain TX power and it knows alone to pass between receiving and transmitting ?
2. There are ANT1 and ANT2, why are there 2? Why can’t the be configured to work together (according to this table they can not, if i get it right) 

3. What changes do I need to put in my code and where to enable the control of the nrf21 ? if i am right transmitting and receiving happens somewhere in the low level of the app in the ncs, so it seems strange to me if i need to change something there

hope to read from you soon

best regards

Ziv

[ziv123]

hi Bendik

Bendik Heiskel said:

I see now that you are using the Zephyr Bluetooth LE controller, the MPSL library supports only the SoftDevice Controller.

i am not sure what that's means, when you referring to an overlay file of the nrf21540 shield it is not something that works with the nrf5 SDK mechanism that does not work with a device tree if i am not mistaken. ??

what if i also have a devkit of the nrf21540, can i run a peripheral and central example from the ncs on it ? how does it work then ?

is it activating the nrf21540 tx booster by its own ?

i must say the documentation on this device and how to work with it is lacking and what there is is a bit confusing 

there is this link:

https://www.youtube.com/watch?v=WC0WYfxLQuQ

of a guy who does some test but what code is he running on the devkits ? how did he configured them ??

hope to read from you soon

best regards

Ziv

[Bendik Heiskel]

Hi Ziv,

ziv123 said:

i am not sure what that's means, when you referring to an overlay file of the nrf21540 shield it is not something that works with the nrf5 SDK mechanism that does not work with a device tree if i am not mistaken. ??

I see where the confusion is coming from. In NCS there is two BLE controllers available, the one developed by us called the SoftDevice Controller, and one from Zephyr.

All of our BLE samples in the nRF Connect SDK uses our SoftDevice controller, and therefore support the MPSL fem library. This means that all of our samples work with the nRF21540DK out of the box when the correct build target is used. When using a different DK the samples can be used with the nRF21540EK when the shield option is added to CMake.

For custom boards the devicetree node for the nRF21540 and the MPSL config options described in Working with RF front-end modules must be added.

What application/sample are you using?

 

Best regards,

Bendik