AC‑SENSE
daisy‑chain AC presence module
A small isolated board that tells your microcontroller whether mains is live - and chains to the next board over five pins, so one ESP8266 can watch a whole panel of circuits instead of just one.
five boards, one chain
What it does
Each AC-SENSE board tells you whether mains is live, without ever letting that voltage touch your microcontroller. The mains side and the logic side are fully isolated from each other.
Boards plug together header-to-header, and each one adds a channel to the chain. Watch one circuit or twenty from a single host, and log when mains went live and how long it stayed that way - not just its current state. Free ESPHome configs for any chain length are on GitHub, ready to flash.
Reading it out just needs a digital input, so it's not locked to ESPHome - Arduino, Raspberry Pi, or anything else that talks 3.3V or 5V logic will work.
- Isolation
- Fully isolated - no direct mains contact on the logic side
- Chaining
- Plug boards together to add channels, one board per circuit
- Terminals
- Screw-terminal mains connection, no soldering to wire it in
- Host
- ESP8266/ESP32 with ESPHome - component and example configs provided free on GitHub - or Arduino, Raspberry Pi, anything that talks 3.3V or 5V
The boards, up close
01 / 02
Firmware & docs
Open source · GitHubESPHome Component
The custom ESPHome component that talks to AC-SENSE over the chain, exposing each board as a binary sensor.
tuksi / AC-Sense-ESPHome-ComponentESPHome Example
Ready-to-flash YAML configs for chains of any length - copy, set your Wi-Fi credentials, and go.
tuksi / AC-Sense-ESPHome-ExamplePick up a board
Built and tested in small batches. Ships from Slovenia via Tindie.