Rebounder Tech Blog

Written by the people who actually run these systems in production.

Digital Signage

Implementing and operating signage on Android devices locked into kiosk mode.

A Poster's Title Shows Up as IMG_1234 on the Classroom TV2026-10-07ScanFilter.setDeviceAddress Throws on the String "null"2026-10-06dpm set-device-owner Launches the App Before prefs Is Set2026-10-05Valid Token, Wrong Scope: an IDOR via design/date Parameters2026-10-03copyOneDay Overwrite Silently Drops Pinned Notices2026-09-19if/else-if as Kotlin's ?.let Return Value Requires else2026-09-08Hand-Built Preview Payload Drifts From the Device2026-09-04insetsController Is null Before setContentView2026-09-01One startActivity Is Not Enough to Blank a Kiosk Screen2026-09-01Media Queries See the Real Viewport in a Scaled Stage2026-08-30An Android Foreground Service Can Die Without Crashing2026-08-17The JMA Evening Update Nulls Today's Temperature2026-08-16FLAG_KEEP_SCREEN_ON Not Working on Android: The Screensaver2026-08-16ESP32 Web Serial API: Live Sensor Data in Next.js2026-08-15Running a Google TV Kiosk for Several Months2026-08-15Building a Power Factor Meter With a Raspberry Pi Pico2026-08-15Google TV or Raspberry Pi for a Signage Device2026-08-15Reading a SwitchBot Motion Sensor Over BLE Directly2026-08-15