4 Replies Latest reply on Apr 29, 2016 9:47 PM by arunhiregange

    Using HCI for debug

    arunhiregange

      Hello,

       

      I would like to use the HCI for debug and I've seen many posts in the past discussing the same thing, but they are confusing.

       

      1) On the one hand there is a document MMPWICED-Smart-QSG203-R.pdf (and posts on this site) which suggest calling BLE_APP_ENABLE_TRACING_ON_HCI_UART will work, as long as the UART_RX pin is disconnected once the application is running. The procedure is given in pages 19/20 of the above document (Viewing Traces from the WICED Smart Tag).

       

      2) In WICED-Smart-Hardware-Interfaces.pdf, page 16 says:

      The BCM20732 has two UART interfaces. One is the factory or HCI UART that is used for programming and factory testing. The other is the peripheral UART, which is available for application use to output debug messages/tracing or to interface with a peripheral device/microcontroller. The following sections describe the peripheral UART only. The HCI UART is not available for application use.

       

      The two seem to contradict each other. Does anyone know?

       

      Thanks.

        • 1. Re: Using HCI for debug
          MichaelF_56

          The HCI UART for all intents and purposes is a programming interface only.  You can also route debug traces to the HCI UART per the instructions in the WICED Smart Quick Start Guide (SDK 2.x and TAG4 Board), but again, if you application requires some form of UART access, only the peripheral UART is available to the application.

          • 2. Re: Using HCI for debug
            arunhiregange

            Hi mwf_mmfae,

             

            Thanks for the answer. However I don't think I fully understood. While you said that "You can also route debug traces to the HCI UART per the instructions .." you also said "if you application requires some form of UART access, only the peripheral UART is available to the application". Could you explain a little on what the difference is that you are making?

             

            i.e. when can we use the debug traces using HCI UART and when will we necessarily have to use P UART?

             

            Is it that with HCI UART we can only output debug strings / traces whereas for a full-fledged bi-directional data transfer then P UART is the only option?

             

            If you confirm this, thanks, I've understood fully.

             

             

            • 3. Re: Using HCI for debug
              MichaelF_56

              The PUART can be used for bidirectional communications with an outside entity via control provided within your bluetooth application.

               

              PUART or HCI UART can be used to display trace output.

               

              The HCI UART is only used for programming the device, and your bluetooth application cannot require services from this port, other than the redirection of traces for debug.

              • 4. Re: Using HCI for debug
                arunhiregange

                Thank you.

                I am able to follow the instructions in the manual to display traces over HCI UART on the IDE debug console window.