Your blind's tilt knob, motorised — without touching anything sealed.
BlindBot is a small open-hardware cap that slides over the existing fluted tilt knob of a Finnish between-glass blind (välikaihdin) and turns it for you. Pull it off to take over by hand.
How it works · Every part · Docs · Build guide · Downloads
Status
This site, with an interactive 3D model, every printable part and the full docs. Parametric OpenSCAD CAD rendered and manifold-checked in CI. Firmware compiled in CI, never run on hardware.
Caliper measurements of the knob and the rod guide clip. First test prints (clip rail, cup + liner). Bench test of the ULN2003A drive and the battery/solar versions. Only a few values come from a real window so far, mostly estimated from photo, not caliper.
Help wanted: knob measurements
- Diameter over the ribs at the top and at the tip
- Fluted length, rib count, rib depth and width
- Shaft diameter and the clip joint
- Knob centre to the frame face; tip to the hinge barrel and to the hook
- Frame width, and where the lift cords run
A caliper and a ruler are enough. Estimates in the repo are not measurements.
What it does
It tilts the slats under Matter control — slowly, quietly, and with layered torque safety so the sealed double-glazed unit is never forced:
No screws, no adhesive on the mechanism. The head pushes up over the knob; a small key on its collar slides into a clip-on rail that hangs from the existing rod guide clip, so the head cannot spin.
An O-ring friction clutch plus firmware current limits and soft end stops sit between the motor and the blind. Turning the knob by hand stays possible at any time.
A single pocket-sized controller (XIAO ESP32C6 + 2× ULN2003A) drives both heads over thin white flat cable, ending in one Matter device with two window-covering tiles. Three power versions: A USB-C, B battery, C battery + solar.
Matter runs over your own network (Thread or Wi-Fi). No account in the cloud is needed to operate the blind after commissioning.
Matter ecosystems
| Ecosystem | Tilt support |
|---|---|
| Apple Home | Working tilt (reported well by Matter testers) |
| Home Assistant | Working tilt (cover entity); best for automations |
| Google Home | Partial — tilt maps to the Rotation trait; app UI coverage is still reported as partial by third-party testers |
| SmartThings | Unconfirmed — test before committing |
Tilt-only device type (Window Covering, 0x0202, tilt + position-aware tilt). Needs a Thread border router for the Thread variant, or Wi-Fi only for the Wi-Fi variant.
