DA14683: FCC Part 15 Testing Setup and RF Functionality


Custom DA14683 Board. 

SDK (last updated in 2018)


I need to go through FCC Part 15 testing on this product.  The test lab has certain requirements for how the radio under test must act for the specific tests they must perform for the certification.  These functions need to be software switchable on the DA14683 so they can go from one test to the other, and the whole system must be stand alone during the testing (not connected directly to a piece of bench equipment).

Yes, I am aware of the following "direct test mode" document: https://www.renesas.com/tw/en/document/apn/b-043-application-note-da1468x-bluetooth-direct-test-mode?language=en&r=1600766

This document does not provide either the functionality or the information to implement the functionality I need.  I have confirmed this with my testing lab that this document is not sufficient to perform the required testing for FCC Part 15.

I would imagine that 100% of companies using your wireless SoC parts need to go through this FCC Part 15 testing (at a minimum) so I am surprised this process is not better documented.

Here are some of the RF operations that need to be accomplished:

1) We will need to be able to position the carrier to the low, mid and high channels and continuously transmit a 100 % modulated carrier with 100 % duty cycle.

2) It would be good to have the capability to change the power levels. Since this device is body worn, the SAR exclusion is low and we may have to lower the power to meet the requirements.


1) Am I missing a document that describes this stuff in detail?  Considering essentially everyone has to go through this process, I would have expected it to be more obvious.

2) If this functionality is available as a stand alone form, how do I access it?

3) The PLT uses a firmware that implements some sort of RF test procedure for it's own testing with the Golden Unit.  Would it be possible to load that firmware to the FLASH, and would it have enough functionality to accomplish the above test requirements (and whatever else is required for FCC Part 15 testing)?

  • Hi Nathan, 

    Working on this question internally. 



  • Hi Nathan, 

    The Bluetooth Direct Test Mode is not sufficient. However, all the required procedures are part of the commands in the RF master which is within the SmartSnippetsToolbox installation. 


    Please check the following document : 


    Section 4.3 describe the commands which are typically used for FCC testing and are put in the GUI in the RF Master.



  • Thank you for the reply.  I appreciate the support.


    As I said above, in my case (and I'm sure many other cases) I can't have a UART port accessible while my product is under test.  It's in an enclosure and the UART is not exposed to the user.  No Access.

    Because of this I need to modify the "PLT_FW" to use the interfaces I have available with the product in the enclosure to execute the commands.  This consists of a physical button to switch between pre-defined tests.

    I have started looking at the PLT_FW project code, but the way it handles both incoming UART traffic and HCI command execution is not straightforward.  

    The "Application note DA1468x Bluetooth© Direct Test Mode" has an appendix called: "Appendix: listing of most common HCI commands for RF testing", which is helpful, but I'm not sure what "most" means in this context.

    I would very much prefer to not have to reverse engineer the UART traffic from the RF Master and then have to debug the execution path in the PLT_FW to figure all this out.  That would suck.


    1) What does "listing of most common HCI commands" mean?  What commands are missing, and where could I find a full list of commands and parameters?

    2) If I had a system without access to the UART, and I wanted to directly execute an HCI command by calling the functions in the PLT_FW project, how would I go about doing that?

  • Hi Nathan, 

    1. You can refer to BLE specs. 

    2. This is something that we don't support. The HCI commands should be sent via UART and this is what the RF Master is doing.



  • Well that is an extremely disappointing and frustrating conclusion.  That adds even more unnecessary time and pain to the process of trying to get this product finished and certified.  Unfortunate.

  • Hi Nathan, Ashley, 

    We do understand the frustration because certification and bluetooth qualification is heavy and expensive. That's the reason why under a certain  product volume it makes a lot of sense to use a certified module. 

    In order to bring your product to the market you will need to get FCC testing certificate and bluetooth qualification testing. You can leverage the Renesas Qualification ID for the controller and the host bu as you implement your own antenna and crystals, you NEED to do Bluetooth PHY qualification.

    As you have read the Direct Test Mode document, you already know the Bluetooth tester send commands to the DUT in order to enter the correct test mode. In one way or another, you will need to expose the UART to the Bluetooth tester to pass qualification. There is no other way around. Usual practice is to have solder pads on the PCB and you can drill the enclosure to wire the UART connection out of the enclosure. That's common practice, also for FCC testing.

    For FCC testing, It is not strictly required to be able to control the device. The FCC will let you load a specific firmware iwhich will get the device enter the specific mode the test is measuring. It's possible to build specific firmware for each test, but that's a rather cumbersome approach and yes you will need to look how to dot that in the PLT firmware. The quick and easy path (which has been successful for a lot of companies) is to wire the UART, load the PLT firmware and use the RF master to control the DUT.

    I hope that shed some useful lights on the requirements.