4 Replies Latest reply on Mar 31, 2020 2:12 AM by user_1536336

    EZ-Serial: BLE pairing with fixed passkey

    user_1536336

      Use-Case

      1. We are using the CYBT-333047 module (CYW20706)
      2. We would like to use EZ-Serial with the CySPP communication interface
      3. The module should work as Peripheral / Server
      4. The module acts as a bidirectional gateway from UART (PUART at the module) and BLE 5
      5. The connection must be encrypted. Enycryption in this case means that a communication should only be possible, if the central device has typed in a valid passkey before writing to any characteristic. The passkey should be generated in the peripheral and is shown at the display of our device. So the central device needs physical proximity to the device to establish a communication. Pairing is not required.
      6. In my opinion the best example to start is the fixed passkey example.

       

      Documentation issues

      Refer to EZ-Serial WICED Firmware Platform User Guide for CYW2070x-based Modules (p. 48)

      1.png

      In my opinion, the yellow colored information doesn't fit together. I use the text format, so the formulated text and the text content fit, but the binary content seems to be different?!

       

      Example reproduction

      This is my communication protocol.

      1.png

      It seems, that there is missing the ENCryption event. Instead of the ENCryption event, I get a DISconnect event.

       

      I tired this example with the Cypress CySMART App (Android and iOS) serveral times, and I'm sure, that I typed in the passkey correctly.

       

      It would be great if anyone could reproduce this behaviour!

       

      Understanding encryption

      What is the API command .CYSPPGP responsible for?

       

      It seems that I just can secure the first characteristic with UUID 65333333-A115-11E2-9E9A-0800200CA101. All other characteristics can be written and read independent of the server_security settings in .CYSPPGP Is that right? In our scenario all characteristics should be secured and not read or writeable until a secured connection is established.

       

       

      Best Regards!