Hi all,
I’m having ongoing issues with a SONOFF MINI-RBS controlling a roller shutter and I’m trying to figure out if this is expected behavior or something wrong in my setup.
Setup:
- SONOFF MINI-RBS (eWeLink)
- Roller shutter motor (unknown model, likely with built-in limits)
- Wall switch is momentary (pulse type) — press to start/stop
- I use the physical switch most of the time
Problem:
- Calibration doesn’t hold — after some use, position becomes inaccurate
- More specifically:
- Closing always works perfectly (0% = fully closed)
- Opening is inconsistent:
- 100% in app = ~70–80% physically open
- 50% can be completely wrong (sometimes almost closed)
What I’ve tried:
- Set external switch type to Pulse
- Set curtain type to Blind/Shutter
- Verified motor direction
- Multiple recalibrations (no interruptions)
- Added extra travel time and recalibrated
- Tested using only the app (no wall switch during calibration)
Observations:
- Closing seems faster and always accurate
- Opening seems slower → suspect timing mismatch
- Using the wall switch (start/stop) seems to make drift worse
- After many tests, sometimes the system stops responding temporarily (maybe motor thermal protection?)
Questions:
Is this just a limitation of time-based calibration on the MINI-RBS?
Has anyone managed to get accurate percentage control with a pulse switch setup?
Is there a “best practice” for travel time tuning when open/close speeds differ?
Would switching to a different module (e.g. Shelly) actually solve this?
Thanks!