The app
One button, and under it the truth about the board: lock state, firmware version and signal strength. It updates itself, outside Google Play.
Access to a particular door is granted separately; installing the app alone lets nobody in.
FlatLock in service
A smart entrance lock for an apartment building. Custom board, firmware and mobile app, from schematic to everyday operation.
What it solves
The building's front door unlocks from a phone, with no fob and no key. It sounds like a detail until you are standing outside with your hands full. Then you just push the door open.
Technical
| Controller | ESP32, Wi-Fi, powered over USB |
| Output | relay with screw terminals, wired in parallel with the door release button |
| Control | MQTT for commands (response in tenths of a second), HTTPS as a fallback |
| Telemetry | relay state, uptime, signal strength – every 5 s |
| Updates | OTA over HTTPS, with automatic rollback to the previous version |
| App | Flutter (Android), home screen widget, self-updating outside Google Play |
| Backend | PHP on my own VPS, permission records, unlock history |
Want something similar?
From the schematic through the board and firmware all the way to the app and the server.
davidpetrov@email.cz • or via contact form