This is a modern, functional ESPHome configuration for the Martin Jerry MJ-ST01 in-wall 3-Way Smart switch. Link to Amazon page.
Download binaries at the latest release:
There was no good YAML config for this device, as the one on ESPHome Devices similar to this is more like the MJ-ST02 with a Tuya MCU rather than this which is a direct relay/LED connection.
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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). -
Aside from the naming it is functionally identical to the MJ-S01 config.
As of my purchase of 3 units from Amazon in March 2025, tuya-convert seems like the most reliable option; it worked perfectly on the first try, though future revisions might not work any longer.
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Install
tuya-convertfollowing their instructions. -
Download the
mj-st01.binfile from the Releases section, or compile the configuration yourself. -
Put the
mj-st01.binbinary into yourtuya-convert/files/directory. -
Power on the switch and put it in "fast blink" mode by holding down the power button for ~5 seconds.
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Run
./start_flash.shand let it perform the initial jailbreak. -
When prompted "Ready to flash third party firmware!", select the
mj-st01.binfile.
Once flashed, the switch will boot into AP mode, ready to be configured via another device to connect to your WiFi and be adopted by the ESPHome Builder in Home Assistant. It leverages a standard "pull the remote config" to permit configuring only the minimum required in the ESPHome Builder, while all functionality is managed by this repository.
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.