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By default the HDP-TTJ-500 will be configured to use the HDMI display connector on the board.  If you wish to use the Seiko LCD display module instead, then following the steps in this guide.

Step-by-step guide


  1. Attach a USB serial cable to the board and use your favourite terminal application to communicate with HDP-TTJ-500.
  2. Interrupt the u-boot sequence before it counts down to zero by pressing any key.
  3. At the command prompt enter the following commands:

    U-Boot > setenv mmcargs 'setenv bootargs console=${console},${baudrate} ${smp} root=${mmcroot} video=mxcfb0:dev=lcd,SEIKO-WVGA,if=RGB24 quiet'
    U-Boot > saveenv
    Saving Environment to MMC...
    Writing to MMC(2)... done
    U-Boot > boot

U-Boot should now boot into Yocto Linux and the graphical window manager should appear as shown in the image below.


Yocto Linux on LCD Display












Touch screen operation

The HDP-TTJ-500 is equipped with a low-power touch screen controller device (TSC2700) which is attached on I2C bus 1 at address 0x48.  No additional setup is needed to enable to touch screen operation of the Seiko LCD display.  You can identify the presence of the TSC2700 in the boot logs:

[    1.941133] input: TSC2007 Touchscreen as /devices/soc0/soc.1/2100000.aips-bus/21a4000.i2c/i2c-1/1-0048/input/input0