This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC2340R5: Compatility with the CC2500 and support of 2-FSK and GFSK with low data rates

Part Number: CC2340R5
Other Parts Discussed in Thread: CC2500

Tool/software:

Hi,

I am looking to use the CC2340R5 in a project that will support BLE communications, as well as support proprietary communications with an old receiving device that uses the CC2500. Looking at other questions on the forum regarding the CC2500 and CC2340, they seem to be somewhat compatible, but not entirely. 

Using smartRF studio 8, it seems that the CC2340 is only capable of GFSK and MSK modulation. Is 2-FSK, as used in the CC2500 not supported? If not, why not? Since it is similar to GFSK I assumed it would be possible.

Also, as said, GFSK is supported, but in smartRF studio I am unable to adjust the symbol rate. I would like to use a lower symbol rate, something like 2.4kbps. Is this possible? If not, I'm just curious why.

Lastly, is the FEC implemented on the CC2500 implementable on the CC2340?

Thank you in advance.

  • Hi Odhran,

    Here are two relevant E2E threads you've likely already reviewed:

    https://e2e.ti.com/f/1/t/1336461 
    https://e2e.ti.com/f/1/t/1280899 

    The PHY that you are asking for is not currently validated by TI and thus not provided in the SmartRF Studio 8 software.  This will update as validated PHYs are added to the CC2340RX device family.  I am asking internally whether there are any additional RF PHYs being planned but I am not confident that your requirements will be included.

    Regards,
    Ryan

  • Hello,

    The closest PHY we offer on the CC2340R5 is the 20 kbps FSK PHY, attached is the rfconfig export with CC2500 whitening and FEC enabled. Please let me know if this works for you.

    Please keep in mind that the 20 kbps PHY on the CC2340R5 does not have any RX capability, meaning you can only use it for TX on the CC2340R5. 

    rcl_settings_fsk_20_kbps_fec.h

    rcl_settings_fsk_20_kbps_fec.c
    Fullscreen
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    // SETTINGS FOR PHY BASED ON RADIO CONTROL LAYER (SOURCE FILE)
    //
    //
    // CODE EXPORT INFORMATION
    // This file is generated
    //
    // Tool name SmartRF Studio 8
    // Tool version 1.0.2.39
    // Created 2024-08-28 11:39:09.796
    // Computer LT5CG2132LP5
    // User
    //
    //
    // WORKSPACE INFORMATION
    //
    // Workspace file -
    // Device CC2340R5
    // Package QFN40 5x5 RKP
    // Revision(s) B (2.0)
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

    Thanks,
    Alex F

  • Hello Ryan and Alex,

    Thank you very much for your responses. 

    The 20kbps FSK PHY with CC2500 compatible whitening and FEC mentioned by Alex is much more towards the proprietary PHY that I require for this design. However, as said, ideally it would be 2.4kbps rather than 20kbps. The reason for this is because the CC2500 has the lowest noise floor with 2.4kbps 2-FSK, and link budget and range is most critical in this application. Also, it is not a problem that only Tx is possible on the CC2340R5 in low data rate 2-FSK mode - as it will only be used as a transmitter. In this application, the CC2340R5 must only be able to Rx in BLE long-range and in 250kbps MSK with CC2500 whitening (which seems to be supported).  

    Therefore, I would like to know, when you mention "The PHY that you are asking for is not currently validated by TI and thus not provided in the SmartRF Studio 8 software.  This will update as validated PHYs are added to the CC2340RX device family" is this purely because they haven't been validated and tested by TI, or because the current SDK does not support it at all? If the former, and the SDK does support it theoretically, I would be happy to validate it myself. I just want to know what's actually possible before wasting any design time on things that aren't at all possible. 

    So, lastly I ask, can the rcl_settings_fsk_20_kbps_fec.h file be adjusted to 2.4kbps instead of 20kbps? Is there a certain field in any of the config structs within that header file which relate to the data rate? 

    Thank you

  • Hello Odhran,

    What Alex has provided is an example of custom PHY development outside of the typical and official validated/tested PHYs supported by Smart RF Studio 8 and the SimpleLink F3 SDK.  It shows that custom PHY creation is possible, but such efforts are not further carried by TI without establishing a critical business need.  We can provide some guidance towards your changes but 2 kbps is a very low data rate so I'm not sure whether it can dependably be achieved on a SimpleLink F3 device(i.e. uncharted territory).

    Regards,
    Ryan

  • Hi Ryan,

    I understand. That being the case, would it be possible for you to share some guidance on what changes to make in order to manipulate the data rate to be 2.4kbps and general guidance on how to create these custom PHYs? 

    I understand that they are official validated or tested and it's at my own discretion to validate any changes made - but it would be incredibly useful for me and no doubt to future customers who come across this thread.

    Thank you

  • Hello Odhran,

    share some guidance on what changes to make in order to manipulate the data rate to be 2.4kbps and general guidance on how to create these custom PHYs? 

    -For this we can do two things, first if you have the 7.40 F3 SDK downloaded you can locate one of the early versions of the PHY files found in (C:\ti\simplelink_lowpower_f3_sdk_7_20_01_10\source\ti\boards\cc23x0r5) (rcl_settings_fsk_20_kbps.c).

    -Second is for me to reach out to the internal team and ask how to change the RCL settings (some registers) to update the data rate, unlike the CC2500 which its very easy to update the data rate, the CC2340R5 is a bit more complex as it requires editing some files. 

    I understand that they are official validated or tested and it's at my own discretion to validate any changes made - but it would be incredibly useful for me and no doubt to future customers who come across this thread.

    -I believe the issue about validation had to do with no RX side existing on the CC2340R5, which made it difficult to validate, as well as the most recent changes I made not being validated at all (other than me testing CC2340R5 to CC2500).  

    Thanks,
    Alex F

  • Hi Alex,

    I can definitely look at the 7.40 F3 SDK for the early versions of the PHYs. However, as I am new to this SoC and not used to the file structure of the firmware, and since changing settings such as data rate is much more complex that expected, it would be great if you could also ask internally to the team for guidance on how to customise things such as datarate.

    Thank you in advance