From a wallpad photo to a home you can control.

Based on August–September 2026 Codex work records, handover notes and retained programs. Generated system illustrations are not photographs of the installation. Checks are limited to the dates and scope recorded.

The starting point was an existing wall controller and its lighting, heating and ventilation equipment. A USB-RS485 adapter connected to a NAS provided a limited command interface, with a HomeKit integration layer built above it.

Agent work focused on control code, state handling, bridge configuration and the operating handover. Physical switching and temperature-setting changes still required on-site human observation. This is a case study of one installation, not a universal wiring guide for every wall-controller model.

The 3 September 2026 report records physical on/off checks for six lighting circuits and five heating zones, plus a target-temperature change in one zone. Ventilation power, three fan levels, bypass and preheat commands were also checked.

The subsequent bridge documentation describes HomeKit lighting, thermostat, fan and auxiliary-switch services. Successful command checks are not presented as proof of long-term reliability or validation of seasonal automation under every condition.

The controller accepts only defined commands and ranges, while coordinating bus writes. Combined climate control checks both switching order and the freshness of device state so that heating and cooling are not intentionally enabled together.

A cooling-delay investigation on 9 September found that heating-off retries and stale state were important to the diagnosis. That investigation did not establish an access-point replacement as the cause, and did not measure the interval from SmartThings handoff to physical air-conditioner startup. Diagnosis and post-change validation need separate records.

Ventilation automation was designed to start in observation mode, checking decisions and logs before enabling automatic commands. Stale outdoor readings are not used to justify automatic activation, and the operator retains manual control and a path back to the original controller.

Device counts alone are not enough to evaluate agent-built controls. Handling stale data, disconnected equipment and repeated requests also matters. This public account omits private network addresses, credentials, entrance-camera footage and device identifiers.

The agent defined AliExpress search terms and specs, then reviewed the user's product screenshots for the FT232RNL adapter, encoder and baluns.

Rear-panel and delivered-part photos separated the control bus from the sub-phone video path. A generated wiring illustration was corrected against the actual connectors.

A USB-RS485 receiver, state parser and bounded commands were implemented, then exposed to Apple Home through a Homebridge plugin.

Lights, heating and ventilation were physically tested. A later heating-state parser fix removed an unnecessary cooling-transition delay, followed by a living-room ON/OFF check.

Physical checks covered 6 light circuits, 5 heating zones, and ventilation power plus 3 fan speeds.

The 9 September 2026 record reports heating-state updates about once a second, 24 parser tests passed and user-confirmed immediate living-room cooling ON/OFF.

Limits: live AliExpress prices and purchase completion were not verified. Ventilation automation remained in observation mode without outdoor-temperature input.

Apple Home → Homebridge on NAS → RS485 agent → USB-RS485 → wall-panel device bus → lights / heating / ventilation