SAFE SCREEN

Inspiration

Emergency alerts were built for broadcast TV and radio. If your family streams everything, the largest screen in your home may never warn you. I wanted the TV to be a safety net, not just entertainment.

What it does Safe Screen is a Fire TV app that shows live US National Weather Service alerts for your state. New Severe or Extreme alerts take over the full screen with a siren and a spoken warning, followed by short, numbered “What to do” steps. You can watch up to three extra states, such as where family lives. Accessibility mode adds larger text and a slow, 1-per-second flash. If the Bedrock backend is on, each alert is rewritten in simple language in one of six languages and labelled as AI-simplified.

How I built it The app is dependency-free HTML, CSS and JavaScript running inside a Kotlin WebView shell on Fire OS. It uses the NWS public alerts API, Web Audio for the siren and the Web Speech API for spoken alerts. An AWS Lambda behind API Gateway, deployed with AWS SAM, calls Amazon Bedrock’s Converse API. The app falls back to the official text if the service is unreachable.

Challenges

Keeping AI from changing safety advice. The prompt only allows facts from the alert, forbids invented instructions and requires every safety-critical step to stay. The screen says plainly that the text is AI-simplified. Navigating with only a remote. I built a spatial D-pad focus system and handled the Back button between the web app and the Android shell. Avoiding alert fatigue. Full-screen takeovers happen only for Severe and Extreme alerts, and only once per alert. Poor connections. The app keeps the last alerts and says clearly that it is retrying.

Accomplishments A complete flow from live official data to a full-screen warning, readable from across a room, with a safe fallback when AI or the network is unavailable.

What I learned Good alert design is about restraint and clarity: interrupt only when it matters, say it simply, and never hide the official source.

What’s next FOR SAFE SCREEN

Alert feeds from other countries (many use the same CAP format), location by ZIP code, and announcing alerts on Echo devices through Alexa+.

Built With

• amazon-web-services
• api
• css
• fireos
• html5
• javascript
• kotlin