7 Replies Latest reply on May 20, 2020 11:12 AM by GaneshD_41

    LMP Response Timeout (0x22) do to an incomple LL_LENGTH_REQ!


      Central/Master: Application built on CySmart 1.3, as well as the CySmart application, on a CY5677 BLE 4.2 dongle, Windows 10

      Peripheral/Server: nRF52833-DK


      40s after Central connects to the peripheral, the peripheral disconnects due to a LMP Response Timeout (0x22). My understanding is that this is a 40s timeout. In the attached Ellisis Bluetooth Analyzer trace (LMPTimeout.btt), we see that the peripheral resumed advertising at 48.702 455 000. Going back 40s, to 8.700 884 500, we have an incomplete LLCP Data Length Update sequence; the nRF sent a LL_LENGTH_REQ to the pSoC4. The pSoC4 never responds, and 40s latter the nRF disconnects and resumes advertising.


      This happens 100% of the time! We use the CySmart/Dongle combination in our automated testing.


      Given that I see it with the CySmart 1.3 application, I assume it's a BLE stack issue. However, is there a CySmart API callback I should implement to force the LL_LENGTH_REQ response?