This is a modern, functional ESPHome configuration for the Martin Jerry MJ-ST02 in-wall 3-way Smart switch. Link to Amazon page.
Download binaries at the latest release:
The original YAML config from ESPHome Devices is OK as a start, but I wanted to ensure optimal configuration similar to my SD01 configuration, so I created this too.
- The config is normalized for recent (2025+) ESPHome versions, including an easier setup process. A pre-built binary in AP mode is available, ready to be flashed with
esptooland adopted easily by HomeAssistant (see below).
I got the Tasmota version of this switch, so upgrading was easy over the air. Simply download the compressed binary (mj-st02.bin.gz) and upload it via the Tasmota WebUI following the process here. If you want to compile it yourself, you can do so and then compress the resulting binary file with gzip, or alternatively install the minimal Tasmota build first to free up space, then install the uncompressed binary.
If you find a bug, please report it by opening an issue.
This device is basic enough that I don't think there's many features to add, but if you come up with one, I'm happy to review it.
Main device information.
Controls entities.
Sensors entities.
Diagnostic entities, including reboot and factory reset if required.