10 Replies Latest reply on Nov 24, 2015 1:43 PM by MichaelF_56

    SDK2.2 BCM20736S SIP in custom board failed to run after programming the application on to it


      I am using SDK2.2 on tag3 board to develop our BTLE custom application.

      In our custom board, we instead use BCM20736S SIP, not the BCM20737S that is populated on the tag3 board.

      (1) The custom firmware is tested out on the tag3 board before I programmed it to the custom board. Our custom firmware is a managed beacon that keeps to beacon until it is connected, than exchange data from an APP for thermal values like sensors temperatures and their configured set points etc.

      (2) In the custom firmware, I have enabled hcl_uart debug streaming, so this is used as an indication to me after programming it to the custom board, the application can run on the custom board if I can see debug messages streaming out to console (teraterm)

      (3) I succeeded to program the custom firmware on the custom board using an external USB serial port, it was straight forward, no hiccup at all.

      (4) However after I removed the external USB serial port, and applied an external 3.3v to the custom board (I confirmed HCL_UART was low as pulled down internally from the SIP), and after I pulled the reset line low for a short period and released it (reset went low briefly and returned to high (high = 3.3v, low=0v)), there was nothing I could see on the console (no debug messages streamed out at all). I also ran my APP to scan it to see if SIP can send beacon for its identification, there was nothing I can see from the APP.


      I am stuck and have no idea why the application could fail after programming it to a custom board, but works OK in tag3 board, the only difference is we use BCM20736 SIP, and tag3 board use BCM20737S SIP.


      I attached our custom hardware board for your reference. The attached schematics is basically a break out board that housed the BCM20736S and has connector which is used for connection to our main host controller board.


      Please advise,

      Many thanks!