Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

AmbystomaLabs — Thu, 21 Jun 2018 13:47:04 GMT

You will have to clarify how you know something is wrong with PA/LNA support in SD132. There are no known problems with it.

The person who wrote this original post was referring to problems with ESB and Gazell.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

Aditya Narayan Tripathi — Thu, 21 Jun 2018 11:18:48 GMT

i am working with SDK14.2(Soft Device Version S132 5.0) and facing the same issue. Sometimes the PA/LNA mode works fine but sometimes it creates the issue.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

Joe — Tue, 29 May 2018 22:54:06 GMT

It looks like SDK 15.0 has PA/LNA support in Gazell and a few bug fixes in the library. I have not tried it yet but I will. Check out the SDK release notes.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

join — Mon, 05 Mar 2018 09:52:49 GMT

We didn't implement PA/LNA control with Gazell because it doesn't provide any information about whether TXEN or RXEN is ongoing, and we couldn't add this ourselves as the GLL library is provided as a static library, not as source code.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

AmbystomaLabs — Fri, 02 Mar 2018 16:19:25 GMT

If you want, I would be happy to review your code. I haven't done anything with Gazelle, it might be fun.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

AmbystomaLabs — Fri, 02 Mar 2018 16:17:59 GMT

You are probably just getting something wrong in the timing or not getting the SKY into the correct TX or RX mode.

It is a lot easier to implement with the shorts enabled. It is just that the PA will come on sometime near the beginning of CW/Preamble. This isn't necessarily bad. Based on my testing it still works fine as long as too much of the preamble isn't lost.

Also you will note from the spec that they use different EEP's to drive the same TEP depending on what they are doing. I had to just black box it and experimentally try all the flavors to figure out what worked.

The best way to verify your solution is to watch the RF envelope synchronous with the gpio for TX/RX enable.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

join — Fri, 02 Mar 2018 15:44:48 GMT

Thanks for the link. We already know your solution and implemented something based on it with PPI and GPIOTE: IIRC, once RADIO emits a READY event, turn on the PA and start a timer whose COMPARE0 event, 4µs later, will trigger RADIO's START task, so that the PA has enough time to warm up, without amplifying too much noise. This also required us to remove the shortcut between RADIO's READY event and its START task in the the latest version of Nordic's implementation. We also tried two other variants that didn't require removing the shortcut (one with a timer, one without), but all of them led to the same poor performance we observed.

If this works for you on nRF52832, though, we'll try to carefully reexamine your examples and re-check if we missed anything. Meanwhile, I'm open to any other piece of advice from any customer or Nordic employee on PA/LNA control without S132.

RE: Controlling a PA/LNA (SKY66112-11) with the nRF52832 and proprietary protocols

AmbystomaLabs — Fri, 02 Mar 2018 15:07:39 GMT

A while back I wrote some PA/LNA code for DTM which is functionally proprietary protocol since it doesn't use the SD.

Basically you just use ppi/gpiote and the radio events to drive the solution. I'm sure you can figure out how to implement from the code.

Here is the link:

https://devzone.nordicsemi.com/f/nordic-q-a/13515/pa-lna-assist-in-dtm-direct-test-mode