Home Safety Workspace (pi4)

Layout

• pet/: voice/camera companion app (Python + ADB + Termux)
• android-flash-kit/: phone flashing/rooting related assets
  • images/: boot/twrp/patched images
  • meta/: kernel/vbmeta/dtb/ramdisk artifacts
  • tools/: magisk/busybox/apk/tools
  • lib/: extracted native libs

Goal

Build a practical home safety system for a 3.5-floor house:

• Easy SOS access (especially near stairs)
• Minimal privacy impact
• Reliable alerts to family

Recommended Architecture (MVP)

1. ESP32 SOS buttons distributed by floor/stairs
2. Pi4 as central receiver and alert router
3. Phone as optional secondary path (not single point of failure)
4. Camera for event-triggered snapshots only (no default 24/7 recording)

Placement Plan (3.5-floor townhouse)

• Floor 1: 1 SOS button near living area
• Floor 2: 1 SOS button near bedroom/living area
• Floor 3: 1 SOS button near frequently used space
• Stairs:
  • 1 button at lower landing
  • 1 button at upper landing
  • Optional: 1 large slap/pull type trigger at middle segment

Suggested device IDs:

• F1_MAIN, F2_MAIN, F3_MAIN, STAIR_LOW, STAIR_HIGH, STAIR_MID

Procurement List

Core

• Raspberry Pi 4B (already available)
• microSD card (high endurance recommended)
• Official/quality Pi power supply
• Stable Wi-Fi AP / Mesh node (for full-house signal)

SOS Nodes

• ESP32 development boards x 5-6
• Large momentary buttons x 5-6 (high visibility)
• Enclosures x 5-6
• USB power adapters + cables (where wall power exists)
• Battery kits for no-outlet areas (stairs):
  • 18650 holder + protected 18650 cells OR AA battery pack
  • Optional charging board / battery protection module

Optional Safety Add-ons

• Buzzer or siren module (local audible confirmation)
• LED indicator strips/buttons (visual confirmation)
• PIR/mmWave sensor for inactivity detection (stairs/high-risk zones)
• UPS/power bank for Pi backup power

Camera (Privacy-first)

• 1 low-cost USB webcam or Pi camera
• Use event-triggered snapshot only, no always-on stream by default

Software Stack (Suggested)

• Pi Receiver: Python FastAPI/Flask or Node.js endpoint
• Transport: HTTP webhook (simple) or MQTT (scalable)
• Notification: LINE Notify alternative / Telegram bot / SMS provider
• Logging: local JSON/SQLite event log
• Heartbeat monitor: offline alert when SOS node stops reporting

Event Policy

• Short press: assist (normal help request)
• Long press (>=3 sec): emergency
• All events include:
  • device_id
  • event_type
  • timestamp
  • battery_level (if available)

Escalation example:

1. Send instant message to family
2. If no acknowledgement in 60 sec, re-alert + backup contact
3. Optional local buzzer feedback to confirm event was sent

Privacy Policy (Default)

• No continuous audio recording
• No continuous public streaming
• Camera snapshots only on event trigger
• Auto-delete event images after retention window (e.g., 24-72h)

TODOs

Phase 1 - MVP (this week)

• Define final button count and install locations
• Buy 2 prototype ESP32 + buttons first
• Build Pi receiver endpoint (/sos)
• Send Telegram/LINE alert from Pi on event
• Implement short/long press detection on ESP32
• Add heartbeat ping from ESP32 to Pi (every 5-10 min)
• Add offline alert if heartbeat missing > 30 min

Phase 2 - House rollout

• Deploy full 5-6 SOS nodes with unique IDs
• Label each device physically (same as device_id)
• Validate Wi-Fi coverage on every floor and stair segment
• Add battery status report + low battery alert
• Add local LED/buzzer confirmation on button press

Phase 3 - Reliability & operations

• Add backup power for Pi (UPS/power bank)
• Add event log dashboard (last 7 days)
• Add monthly maintenance checklist
• Run family drill: simulate emergency and verify notification path

Maintenance Checklist

• Weekly: test at least one button per floor
• Monthly: battery inspection/replacement plan for stair buttons
• Quarterly: full end-to-end emergency drill

Notes

• Existing pet/ app remains available for voice/camera interaction.
• Safety SOS path should be independent from voice recognition reliability.