topic Re: kw41z with sky66112 in Wireless MCU

kw41z with sky66112

gaetanonugnes — Thu, 26 Sep 2019 04:44:07 GMT

Hi,

i'm trying to connect the KW41Z with SKY66112. on my prototype board the pin of skywork are connected to the following pin:

CTX -> PTC2

CRX -> PTB3

ANT_SEL-> PTC4

CHL ->PTC6

CPS->PTC5

CSD ->PTB2

I'm trying to configure the chip with FAD of kw41z. I have enabled the FAD algorithm, setted the Timing49 (FFFFF01) and Timing50 (FF01FFFF), i m using FAD (FAD_EN=1,ANTX_EN = 11, NOT_GPIO = 0111). In this configuration the rx_switch is disabled because the pin crx was mounted with wrong pin(I put ptb3 pin always high).

My problem is that the signal is very low.

My board can't communicate with external router if is not near the sensor.

I noticed that the PTC6 is always low, even if set as gpio and high. But this should not interfere with the behavior of the PA/LNA.

Any help is very appreciate.

Thanks

Re: kw41z with sky66112

Sebastian_Del_Rio — Thu, 26 Sep 2019 17:59:34 GMT

Hi Gaetano, I hope you're doing well!

Could you please take a look at this Reference Design? It's using the same SKY6612 that you're using.

There you will find to use as a reference the layout, schematic, Gerber files and BoM.

Also, in the software side, you can use the configurations used in the SDK-FRDM-KW41Z_PA as a base, but please take into account that the included SDK is not the latest one. You will need to download the latest SDK and migrate the changes in the examples code to the newest version of the software.

Hope it helps you.

Best regards,

Sebastian

Re: kw41z with sky66112

gaetanonugnes — Sat, 28 Sep 2019 06:44:30 GMT

Hi, i checked the reference design and i ported in my SDK the commands to activate the FAD.

I was using the zigbee application demo "end device".

With oscilloscope all works fine. I see the ctx pin moving when trasmit something..

But i have 2 question:

1) my tx power seems too low, i can't reach the receiver if it is not very near to trasmitter, so i think that sky66 is not working well or i have to modify something on db gain parameter in nxp.

2) in the example demo there isn't a radio init function, so i don't know when the radio is initialized. In my main i need to insert xcvr_init to access and modify FAD register.

Could you help me to find the power amplifier settings in nxp and how to init correctly radio module?

Re: kw41z with sky66112

Sebastian_Del_Rio — Mon, 30 Sep 2019 15:59:48 GMT

Hi Gaetano,

Tx power can change depending on external factors, such as physical obstructions, network congestion, and possible electronic interference on the same range of frequencies that you're working in. You could try changing the connection channel, or testing in a different environment to see if there are any changes to transmission power.

The SKY66112 gets initialized in the ApplMain.c source file of the project, by calling the sky66112Init function. This function only gets executed if the "FEM_SKY66112" macro gets defined as 1.

The PA is also initialized inside this function by calling the XCVR_ExternalPAInit function.

To see how this is done, I would recommend checking one of the provided examples and locating the functions I described previously.

However, you will need to implement this in your ZigBee project yourself, based on the provided examples of the PA SDK provided for this reference design, since the PA SDK version didn’t include support for ZigBee, but the current one (that can be found here) does.

Please let me know if you need more information.

Best regards,

Sebastian

Re: kw41z with sky66112

gaetanonugnes — Mon, 30 Sep 2019 16:13:29 GMT

Hi,

i check the project and implemented it on my SDK.

The function that you indicate call XCVR_ExternalPAInit, that call XCVR_Init..I would know when in the stack the PHY is initialized.

In main of "end_device" sample there is no init function for PHY. So where is the right place to put the SKY66112 Init function?

In order to manage the stack zigbee i need to know how it initialize the phy, and when..

Best regards,

Gaetano

Re: kw41z with sky66112

Sebastian_Del_Rio — Tue, 01 Oct 2019 20:04:37 GMT

Hi Gaetano,

The setup for the SKY66112 can be done during the hardware setup part of the MCU's initialization process, for example, when the Pin Mux is getting initialized or in the ApplMain.c source file.

Best regards,

Sebastian