Add Sonoff SWV2C valve support

[yezi289]

Check all that apply

Type of Change

• WWST Certification Request
  • If this is your first time contributing code:
    • I have reviewed the README.md file
    • I have reviewed the CODE_OF_CONDUCT.md file
    • I have signed the CLA
  • I plan on entering a WWST Certification Request or have entered a request through the WWST Certification console at developer.smartthings.com
• Bug fix
• New feature
• Refactor

Checklist

• I have performed a self-review of my code
• I have commented my code in hard-to-understand areas
• I have verified my changes by testing with a device or have communicated a plan for testing
• I am adding new behavior, such as adding a sub-driver, and have added and run new unit tests to cover the new behavior

Description of Change

Summary of Completed Tests

[CLAassistant]

All committers have signed the CLA.

[yezi289]

I have tested this with a physical Sonoff SWV2C device. It pairs successfully in the SmartThings app, and both valve controls work normally.

[ldeora]

I have tested this with a physical Sonoff SWV2C device. It pairs successfully in the SmartThings app, and both valve controls work normally.

That's the easiest part, but does it stay on for longer than 10 minutes or does it automatically turn itself off after 10 minutes? What happens after - say - 15 minutes?

The device is completely useless when it turns itself off after 10 minutes. Users don't want to turn it on every 10 minutes if they want to irrigate for an hour.

Discussion:

https://community.smartthings.com/t/st-edge-sonoff-hydro-one-duo-family-swv-zfe-swv-zfu-swv-zne-swv-znu-swv-zf2e-swv-zf2u/309672

It's a bit more complicated (link to (outdated) code and technical documentation):

https://community.smartthings.com/t/st-edge-sonoff-hydro-one-duo-family-swv-zfe-swv-zfu-swv-zne-swv-znu-swv-zf2e-swv-zf2u/309672/106

[ldeora]

Another issue: before a channel is turned on, the opposite channel must be turned off. According to the official manual only one channel should be open at any time.

https://github.com/ldeora/SmartThingsEdgeDrivers/blob/main/sonoff-hydro/TECHNICAL_DOCUMENTATION.md#19-hydro-duo-architecture

[yezi289]

I tested this with a physical Sonoff SWV2C device.

For the 10-minute behavior: yes, the device has an internal default auto-close/manual watering duration. In my test, if a valve is opened normally, the device closes it automatically after the configured duration. The default value appears to be 10 minutes. Users can change the irrigation/manual watering duration through the device's own configuration path outside of this basic valve control behavior.

For the dual-channel behavior: I also tested the mutual exclusion behavior on the physical device. The two channels cannot stay open at the same time. If channel 1 is open and then channel 2 is opened, channel 1 is automatically closed and channel 2 opens. The device firmware reports the valve state automatically when a valve is operated, and the SmartThings app state updates correctly from those reports.

If preferred, I can update the driver to explicitly send an Off command to the opposite endpoint before opening the requested channel, so the SmartThings state stays aligned with the device behavior.