A high-quality smart light switch — clamps over the wall plate, no rewiring needed.
24 GHz mmWave radar presence detection, local sleep tracking, five operating modes, a dual-arm mechanical toggle, and full Alexa + Google Home integration — all running on a single ESP32-C6.
This non-invasive smart light switch controller is designed to sit directly on top of a standard physical rocker switch. By using a precise micro servo to physically toggle the switch, it bypasses the need for electrical rewiring or neutral wires, making it compatible with any home wiring standard.
Operating entirely on low-voltage DC power, the device integrates advanced radar presence sensing, local sleep tracking, smart blind synchronisation over MQTT, and native smart assistant connectivity, transforming a basic physical switch into a fully integrated smart home hub.
All components connect to the central ESP32-C6 processor. Sensors are on the left, actuators on the right, and cloud services below.
The sensor detects stationary people by measuring subtle chest movements from breathing — solving the classic problem where lights turn off when you sit still. Features a range of up to 6.75 metres.
Processes sleep habits entirely on-device. Tracks sleep consistency, duration, cycle alignment, and bedtime timings without sending any data to the cloud.
Auto, Manual, Alarm, Bedtime, and Locked. All inputs — physical touch, MQTT commands, alarm schedules, presence detection, and safety triggers — flow through a central controller for smooth and predictable transitions.
New software updates are only saved after a successful boot and network connection. Configuration files are mirrored with checksums to prevent corruption, and failed updates automatically roll back.
Wi-Fi 6, simple Bluetooth setup, local MQTT support, smart assistant integration (Alexa & Google Home), weather updates, and automatic time sync.
Automatically turns off when the room is empty to save energy and prevent screen burn-in. A drifting screensaver displays the time and weather when idle, moving around the screen to protect the pixels.
Traditional motion sensors only detect active movement. The switch's radar scans across 9 distance zones and uses a custom filtering process to detect even the tiniest movements, like breathing, while filtering out motor noise.
Uses a fast filter to capture immediate movements for an instant turn-on, and a slower filter to track micro-movements (like breathing) to keep the light on when you are sitting still. Both filters are designed to run efficiently on the small processor.
The sensor requires clear movement to turn the light on initially, preventing false triggers from drafty air or electronic noise. Once the light is on, the sensor becomes much more sensitive so it won't turn off while you are sitting still.
On startup, the system scans the room to measure background noise. Every 30 minutes when the room is empty, the sensor automatically recalibrates to adjust for environmental changes like temperature and humidity drift.
When the mechanical motor moves to toggle the light switch, the sensor temporarily pauses detection to ignore the physical movement and electrical noise. After a brief 2.5-second cooldown, it smoothly resumes monitoring.
| Component | Model | GPIO | Protocol | Function |
|---|---|---|---|---|
| Actuator | SG90 Servo | GPIO 2 | PWM | Dual-arm switch toggle |
| Motion binary | LD2410C mmWave | GPIO 14 | Digital In | Hardware presence signal |
| Radar RX | LD2410C UART RX | GPIO 20 | UART @ 256k | Telemetry & config |
| Radar TX | LD2410C UART TX | GPIO 0 | UART @ 256k | Telemetry & config |
| Touch (action) | TTP223 | GPIO 3 | Digital In | Toggle / single tap |
| Touch (menu) | TTP223 | GPIO 1 | Digital In | Menu / calibration |
| Display SDA | SSD1306 128×64 | GPIO 21 | I²C @ 400k | OLED data line |
| Display SCL | SSD1306 128×64 | GPIO 22 | I²C @ 400k | OLED clock line |
Strapping pins 8 & 9 (boot mode / log output), 4–7 and 15 (JTAG / flash SPI), 18–19 (USB-JTAG) all left floating to keep boot deterministic.
Every morning, the switch calculates a sleep quality score based on four distinct measurements. All data is processed locally and never leaves the device.
Bedtimes are mapped onto a circle so that times crossing midnight average correctly. Standard averages would incorrectly place 11:30 PM and 12:30 AM at noon.
Calculates a sleep duration score centered on the target goal, encouraging optimal sleep length.
The smart light switch shares room occupancy data with a companion blinds controller over the local network to manage comfort automatically.
When the motion sensor detects that the room has been empty for a set period, it sends a message over the local network to the companion blinds controller. The blinds then close automatically to keep out summer heat or trap warmth during winter. You can learn more about the blinds controller on its own portfolio page.
While Wi-Fi is the primary connection, the switch is fully capable of offline operation. If Wi-Fi drops, a backup Bluetooth mode enables easy setup and recovery.
A custom web application — installable on your phone, tablet, or computer — serves as the main control panel. You can toggle the light, adjust modes, manage schedules, view sleep scores, and fine-tune sensor settings. It communicates locally over your home network, making it completely private and offline-capable.
Easily configure the device over Bluetooth on first startup. If Wi-Fi goes offline, a backup Bluetooth recovery mode activates automatically, allowing you to update credentials or check status without taking the device off the wall.
Control the switch with your voice using standard Alexa or Google Home commands via a secure cloud bridge, with no complicated setup required.
Sends status updates (light state, motion levels, sleep scores, and temperature) to your local home server and accepts remote commands for advanced custom automation.
Retrieves local sunrise, sunset, and temperature data to coordinate daylight savings and automation schedules. Time zones and daylight saving changes are handled locally after startup.
A planned firmware update will pair the switch with the self-balancing desk robot over MQTT — using the robot as an auxiliary sensor to expand presence coverage into the rest of the room and forward voice commands. Topic schema is reserved; the integration ships in a later release.
The ESP32-C6 is one of the first hobbyist microcontrollers with native Wi-Fi 6. By using a feature called Target Wake Time (TWT), the switch schedules precise wake-up windows with your home router. The wireless radio sleeps in between, dramatically reducing power consumption.
Standard Wi-Fi keeps the wireless antenna active constantly, wasting energy for a device that only needs to communicate occasionally. With TWT enabled, the switch and router agree on specific microsecond windows to transfer data, allowing the radio to sleep most of the time.
This feature is optional and can be toggled in the companion web app. If disabled, the radio remains active for absolute minimum latency. In everyday use, keeping power saving enabled provides instant responses while reducing heat and saving energy.
The motor is disabled for the first 15 seconds after booting while the power supply fully stabilizes. This prevents sudden power drops from resetting the device.
Settings are saved in two separate memory slots with verification checksums. If a power cut occurs during a save, the device automatically restores your settings from the backup slot on startup.
If the device experiences 3 consecutive unexpected restarts, it pauses the motor, Wi-Fi, and sensor, displaying a warning on the screen. It automatically attempts a normal recovery after 10 minutes.
New updates are only permanently saved after the device successfully starts up and connects to the network. If an update fails or causes a crash, it automatically reverts to the previous working version.
If the primary settings slot fails validation on startup, the device automatically loads the backup settings.
A future software update will connect the switch with the self-balancing desk robot. This will allow you to use the robot's voice command system to toggle the lights or check your sleep stats without opening the app.
Connecting both devices over your home network will also allow the robot to serve as an extra motion sensor, helping to cover blind spots and coordinate automations across your entire room.
Manage all devices, view sleep quality scores, and configure mmWave radar parameters remotely.