Porting ncs example code to Fanstel BT840X that has an internal skyworks PA/LNA

[Orangepeel]

I am looking to take example codes for the nrf52840dk and run them on a Fanstel BT840X EV board. I am looking at the central and peripheral coded low data rate firmware but want to achieve a much greater range by using the RF amp and LNA. Can anyone point me to some examples that might demonstrate of give some idea how to do this. I am using NRF connect SDK 2.2.99 with visual studio. I have got the Fanstel BT840X range test code working and I have been able to port the examples for the nrf52840dk to the Fanstel BT840X EV board but cannot get the extended range. Does the code need to control the switching of the PA/LNA as at the moment I have the PA fixed on and LNA off.

[Amanda Hsieh]

Hi, 

Take a look at https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.2.0/nrf/ug_radio_fem.html#adding-support-for-skyworks-front-end-module and this post. 

Regards,
Amanda H.

[Orangepeel]

HI Amanda,

Yes I am aware of that link and the post is the most relevant to my question that I have found.

I do get this message "CONFIG_MPSL_FEM was assigned the value y, but got the value n. Missing dependencies:
MPSL_FEM_ANY_SUPPORT" when I add CONFIG_MPSL_FEM=y to my prj.config file.

I dont have a great understanding of how the PA and LNA are switched. I assume that the BT driver knows when to configure this switch. I am controlling with GPIO the PA and LNA lines into the Skyworks device so I assume that I am not controlling well enough these lines as I have a very poor range. I have been measuring the power draw and I do get peak power consumption of around 200mA.

Any more assistance gratefully recievied.

[Orangepeel]

Hi Amanda, I now have a much higher power consumption during TX and consequently greater range. I do not get the same power consumption as seen from using Fanstel BT840X example hex. The hex code peaks at 225mA and my code peaks at 200mA. Any idea why that might be?

[Orangepeel]

Also, How to I check that the module is running at 125Khz. Are there any settings that force 125Khz?

[Amanda Hsieh]

Hi, 

Orangepeel said:

I now have a much higher power consumption during TX and consequently greater range.

You should check the product specification for the power consumption of Fanstel BT840X/sky66112-11 in TX mode. 

Orangepeel said:

The hex code peaks at 225mA and my code peaks at 200mA.

What is the hex you are comparing to? Not sure what your code is, but it depends on the functions in the code. 

Orangepeel said:

How to I check that the module is running at 125Khz. Are there any settings that force 125Kh

What module do you mean here?

-Amanda H.

[Orangepeel]

Sorry, I meant how can you check that the data rate is 125Khz for long range?

[Amanda Hsieh]

Hi, 

Do you mean coded phy data rate 125 kbps?

If so, you can take a look at the Central Heart Rate Monitor with Coded PHY and the Peripheral Heart Rate Monitor with Coded PHY samples and check with nRF Sinffer. 

-Amanda H.

[Orangepeel]

Hi, I downloaded the software required for the nRF sniffer but soon as I choose the option scan and follow devices on LE Coded PHY, under extcap interface settings, it captures some other BT data and then does not capture anything more. I note that the LED on the dev board also stops flashing once this setting is set.

[Amanda Hsieh]

It needs an extra nRF device to program as an nRF Sniffer. Please note that not all the nRF devices can support LE Coded PHY. See the Supported Features table in the Minimum requirements doc. Please create a new support case if you still have issues. The latest issue is away from the original scope. 

-Amanda H.