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home_iot_device
Home Automation
BLE Beacon Mesh Home Automation
Retrofit switchboard system
A complete retrofit home-automation system — custom mains-side hardware, a custom BLE beacon mesh protocol and an Android app — that ran a real house for 2+ years of continuous operation.
2+ years
Continuous daily operation
1 : 16
Main board to switch modules
No hub
Hubless, cloudless control
- Client
- In-house R&D project
- Delivery
- In-house / founder project
- Role
- Solo designer — hardware, enclosure, firmware, protocol and app
- Timeline
- 2018 – 2019 · field-tested 2+ years
Stack
nRF51822 Embedded C Custom BLE beacon mesh Android KiCad FreeCAD
help The problem
Smart-home products mostly assume new wiring, a WiFi hub or a cloud subscription. The goal here was a retrofit system for traditional modular switchboards: no rewiring, no hub, no cloud — and a bill of materials low enough for whole-house deployment to make sense.
build What we built
- Hardware in the switchboard's own form factor: a 5×5 cm main board and 2.5×5 cm switch modules sized to drop into standard modular switch plates.
- Cost-engineered architecture — the main board carries the controller, a custom AC-DC supply, EEPROM and solid-state switching, and one main board drives up to 16 switch boards, so the expensive parts are bought once per room cluster rather than once per switch. That single decision collapses the whole-house BOM.
- A custom BLE beacon mesh designed from scratch, letting every board in the house relay status and commands with no hub and no pairing ceremony.
- An Android app that joins the beacon mesh directly, showing live switch status across the house and controlling any switch.
- PCBs in KiCad and enclosures in FreeCAD — the modules had to fit standard switch plates mechanically, not just electrically.
check_circle The result
- done Deployed in a real home where it ran for more than two years of daily use, with one hardware failure in that time — the AC-DC stage fused after a short in the home's power inverter, an external fault.
- done Mains-adjacent hardware design, cost engineering for BOM-sensitive products, custom wireless protocol design and multi-year field reliability.