Bluetooth BLE/52832/ Try to implement FTMS control point with Zwift

[Vincent25]

Behaviour:

- Bluefruit the feater (nRF82832)

- Bluetooth BLE

- Implementation of Fitness Machine Service (0x1826)

- What is correct : all characteristics notified to the client

- What is wrong : the implementation of the flow char of control point characteristic (0x2AD9)

I think now i understood the concept of control point.

I receive a write from the client into it and i try to answer with an indication.

But the client don't continue the configuration of the control point.

I think it should write 04 to set the resistance level, but it didn't

I give you the sequence diagram beetween client and server.

Maybe you can tell me what is wrong

Thank you

Vincent

Implementation of Fitness Machine Control Point
Specification : Fitness Machine Service (0x1826)

 Zwift(Client)                                                             HomeTrainer(Server)                                         Meaning
                       
                             FTMS.CtlPt(0x2AD9) write(7)                                                                       Start or Resume a training session 
                    ------------------------------------------------------------------>    
 

                           FTMS.CtlPt(0x2AD9) indicate(0x8001)                                                         Reply: OpCode=0x80 and  ResultCode=0x01
                    <------------------------------------------------------------------

                             FTMS.CtlPt(0x2AD9) write(0)                                                                        Request Control: initiate the procedude to request the control   

                     ------------------------------------------------------------------>                                              of the fitness machine 

                              FTMS.CtlPt(0x2AD9) indicate(0x8001)                                                         Reply: OpCode=0x80 and  ResultCode=0x01
                     <------------------------------------------------------------------

Remarques:

                    1- In the server software the source is the following:

                                   call back OnWrite (characteristic FTMS control point (2AD9):
                                              indicate16 (0x8001)   //renvoit 2 octets 0x80 and 0x01

                   

                    2-I tried to indicate 0x0180, but without any success
                    3- The structure to indicate to the client is (in my opinion) the following:

                                   struct
                                       { OPCODE:   uint8  //0x80 (cf specification p 50/78)
                                          RESULTCODE: uint8  //0X01=SUCCESS
                                        }
  
  

                    4 - the initialisation of the control point is the following:

  //control point pour le controle de la resistance par zwift
    m_ControlPoint.setProperties(CHR_PROPS_NOTIFY |CHR_PROPS_WRITE |CHR_PROPS_INDICATE |CHR_PROPS_READ  );
    m_ControlPoint.setPermission(SECMODE_OPEN,  SECMODE_OPEN);
    m_ControlPoint.setWriteCallback(fctWriteCallback);
    m_ControlPoint.setCccdWriteCallback(fctCCCdCallback);  // Optionally capture CCCD updates   ?????
    m_ControlPoint.setFixedLen(2);
 

[Edvin]

Hello,

I am not sure I follow you here. This service isn't something that you found in our SDK, right? I can't find any references to FTMS or FMS in our SDK, and the code looks like C++.

I suspect that this is from an SDK from somewhere else, and if so, you have to ask them how it is supposed to work.

Best regards,

Edvin

[arlenn]

Vincent25, I am trying to do the EXACT same thing.  However you appear to have gotten father than I have.  Would you mind if I emailed or sent you a DM for some hints on how to set up the advertising on the feather?  I am finding the use of FTM to generally be very poorly documented.

Thanks in advance,

[Vincent25]

Hi arlenn,

Yes you can.

If you have some questions about this project. give me your mail.

no problem

what's your aim with Zwift?

best regards.

Vincent

[Pcel]

Hi,

I’m also working on Zwift and FTMS, I have made some progress but I’m quite stacked right now. Could we share our progress?

Thank you very much!