I’m experiencing a persistent calibration problem with my Sonoff MINI-RBS (Firmware 1.0.3, eWelink 5.18.0). I know this might not be a dedicated support forum, but I’m really hoping some other users here might have insights or solutions to share.
My Setup:
I have standard 4-wire blind motors (forward, backward, ground, neutral). These motors work perfectly with my old Lonsonho QS-Zigbee-C03 controller, where I perform manual calibration (since these motors draw very little current, calibration needs to be set manually). The true open/close time for my blinds is approximately 20 seconds.
The Problem with MINI-RBS:
When I try to calibrate the MINI-RBS, whether through the eWelink app or the device’s physical button, the calibration appears to complete successfully. I can manually set the open/close times to around 20 seconds.
However, after confirming the calibration, the MINI-RBS doesn’t seem to retain these settings. When I issue a “full open” or “full close” command from the eWelink app, the motor relays click, and the MINI-RBS always keeps the command active for exactly two minutes, regardless of the 20-second calibrated time. Two minutes is, as I understand, the default maximum run time for the device. It simply never stops at my calibrated 20 seconds.
What I’ve Tried:
Calibrating using all possible methods (app and device button).
Due to this issue, I’ve had to revert to my old controllers – both a Shelly and a Lonsonho Zigbee controller – which are both working perfectly.
Has anyone encountered a similar problem with the MINI-RBS not respecting calibrated times and defaulting to the maximum run time? Any suggestions or workarounds would be greatly appreciated! I’m also wondering if adding a numeric input option for timings would be a good feature addition, as it would help in situations like mine.
Hi. I’m also having trouble with the MINI-RBS. I can’t calibrate it either.
I can start and stop the engine manually, but the automatic shutdown doesn’t work.
Thanks for your suggestion, but I’m afraid it doesn’t address the core issue.
My motors already have their limits properly configured and they stop exactly where they should. The problem isn’t the motor overrunning; it’s the Sonoff controller itself continuing to send the “open” or “close” command for a full two minutes, even though the calibration for the blind’s travel time is much shorter (e.g., 20 seconds).
This means the controller is incorrectly prolonging the command signal well past the actual calibrated travel time. All other smart blind controllers I’ve used on the market stop sending the command once the calibrated travel time has elapsed. At this point, I don’t understand the purpose of having the option to extend the calibration time if the controller always sends a two-minute command anyway…
The MINI-RBS controls the curtain’s position using precise timing based on a percentage scale. For example, moving the curtain from 1% to 51% open runs the motor for half of the total calibrated time. However, because the motor takes a moment to start, it may not reach exactly 51%, stopping closer to 49%. This small discrepancy means the curtain’s position isn’t always perfectly accurate and can worsen if repeatedly stopped mid-position.
To ensure the curtain fully opens (100%) or closes (0%), we add a 2-minute buffer to these commands. This extra time guarantees it reaches its endpoint despite minor timing variations.
The motor usually has built-in limits that automatically stop it at fully open or closed positions. So even if MINI-RBS keeps the relay on, the motor stops itself—eliminating any risk of damage.
We realize this solution might seem radical, so we’re considering adding a feature that lets you customize buffer times for full open and close commands. What do you think? We’d love your feedback!
I’ve looked into the two-minute run time thing more deeply and, thanks to your explaination, I now understand the logic behind this timing. It’s a really smart way to ensure that the fully open and closed positions are always reached, preventing any drifting or misalignment over time. Thanks for clarifying!
I completely agree with the idea of making this “buffer time” customizable. There are definitely scenarios where keeping the command active for two whole minutes might not be ideal. Being able to reduce this “extra time,” perhaps down to 10 or 20 seconds, would be a fantastic improvement and would make the system much more versatile for various applications.
This preset maximum time is what non-IOT pickups use, which only guarantee the relays’ interlocking, ensuring that the motor’s upper and lower limits are properly regulated.
What advantage does this device have over the Dual R3, aside from its size? I thought it compensated for the non-linearity of the opening percentages with the position, by not constantly raising or lowering the blind when the roller’s winding radius varies.
Install the new ZBRBS zigbee version and do not disconnect the relay at any time.
More than an hour later, the relay was still energised.
It’s a shame, it was the only thing I had left with Wi-Fi and blinds.
The Dual R3 stops energising the relay about 3 seconds after completing the cycle.
I don’t feel confident with the ZBRBS controlling the relays in my entire home 365 days a year, 24 hours a day, and without knowing their quality, I don’t think these coils will last very long.
