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Caveats

This page documents the known issues and limitations for the Android 14 build on Tachyon.

Known Issues​

1/ Screen orientation defaults to portrait​

  • Issue: The default HDMI/USB-C display orientation is portrait.
  • Workaround: Use adb to set an override size (see commands below) to force landscape. This setting persists across reboots until reset.

2/ USB2 host power not enabled​

  • Issue: Only USB1 works for keyboards/mice today. USB2 does not power up yet.
  • Workaround: Plug input devices via a USB-C hub on USB1 or use your USB-C monitor’s downstream ports.

3/ 40-pin header not yet accessible​

  • Issue: 40-pin header (GPIO, I²C, etc.) is not exposed to Android user space yet.

4/ CSI/DSI cameras & displays limited​

  • Issue: Camera/display drivers function on internal dev modules, but Arducam and other commercial modules need additional porting.

5/ Google Play not bundled​

  • Issue: No Play Services / Play Store included for licensing reasons.
  • Workaround: Sideload APKs via adb. (Advanced users may flash GApps at their own risk.)

6/ Display lock timeout​

  • Issue: Screen locks every 1 minute by default.
  • Workaround: Change the timeout (or disable lock) in Settings.

7/ Verified boot & OTA sideload​

  • Issue: Verified boot is not enabled; OTA sideload tooling not yet supported.

8/ Brightness control on HDMI​

  • Issue: Brightness control does not affect HDMI output.

9/ Analog & telephony audio​

  • Issue: Speaker/headset/mic paths untested (audio does play); telephony audio is untested though calls appear to initiate.

10/ PCIe and haptics​

  • Issue: PCIe not tested; haptics not present on the board.

11/ Device & connectivity management​

  • Issue: Device Management is disabled. Connectivity Management works, but eSIM profile manipulation is disabled in this build.

Additional Notes​

USB & input for first-run setup​

If you lack touch input, connect a USB keyboard/mouse via USB1 (through a hub or monitor) or use ADB input commands (see below) to wake/unlock and navigate.

First boot experience​

On first boot you may see a brief black screen as the system settles. If using HDMI in portrait, apply the wm size override for landscape via ADB.

ADB rotation helpers​

Force Landscape:

adb shell wm size 1920x1080

Force Portrait:

adb shell wm size 1080x1920

Reset:

adb shell wm size reset

Check:

adb shell wm size

Useful ADB input shortcuts

Wake:

adb shell input keyevent 224

Unlock:

adb shell input keyevent 82
adb shell input keyevent 3

Swipe to unlock (1080p):

adb shell input swipe 540 1600 540 800

DPAD navigation:

adb shell input keyevent 19 ; adb shell input keyevent 20 ; adb shell input keyevent 21 ; adb shell input keyevent 22 ; adb shell input keyevent 23