• Touchpad mistery solved, rerouted board.

    Miklos Marton4 days ago 0 comments

    After googling about the ELAN microelectronics corp, I came across the following patchset submitted to the Linux kernel:

    https://lwn.net/Articles/496137/
    It turned out that the touchpad I2C interface is used as a I2C - HID interface. It is in the vanilia mainline now, so it seems to be a good starting point. Basically I will need to create an I2C - HID - BLE - HID converter.

    I have also rerouted the board to align the MIFA antenna to the proper direction:

    Also made some paper printouts to verify the physical dimensions:

    The BLE module footprint had some problems, but fixed now. The rest of the connector verification waits to my PID controlled flat iron because removing the FPC connectors will require preheating what I do not really have ATM.

  • Touchpad calvary

    Miklos Marton09/17/2017 at 13:37 0 comments

    The notebook is equipped with a touchpad manufactured by Elan microelectornics Corporation. The board number is 2H214-14201 Rev B. The controller IC is Elan 339360-3100. I have found no information about them on the web. I might run a round with Elan in e-mail, but I do not really have big hopes about it.

    I do not have schematic for the original mainboard but have one for an another similar Samsung Ultrabook with discrete graphics codenamed Miranda 13H-EXT.

    The pinout of the touch connector is the following:



    The KBC3_TCLK/TDATA goes to the superio/micom while the SMB3_CLK/DATA hooked to the PCH's SMBUS to the same one which connects the RAM slot's SPD eeproms. Unfortunately I have no luck powering up the board to boot (if I could not this conversion would be it's destination), so I could not run an I2C detect from Linux to see it is answering.

    The KBC3_TCLK/TDATA interface I guess is a PS2. I will power up the board's P3.3V to see if it outputs the clock. PS2 differs from I2C so it would be tricky to interact with it. SMBUS would be better because it could (or should due the lack of free pins) share the same bus with the lipo battery gauge.

  • Antenna orientation

    Miklos Marton09/16/2017 at 08:24 0 comments

    After routing the initial layout I have came across some antenna design related material namely the AN91445 from the Cypress. Section 7.1 covers the YJ-14015 antenna type (MIFA == Meander Inverted-F Antenna).

    By seeing this radiation pattern:

    The current orientation is not the best (most likely the keyboard is going to be used in front of the receiever).

    It's time to update the design.