Can anyone help me keep our bedrooms cool on long hot summer nights, while avoiding wet carpets?
I have made a prototype window auto-close unit that combines a rain sensor, an Elegoo Uno R3, a Pololu high-power 36v4 motor controller and a 24v/4.2A stepper motor into a single unit - all powered by a 24v/5A mains (240v UK) adapter. The unit is completely portable and self-contained - there is no data or power connection to a laptop, PC or similar device.
It performs a very simple, one-off operation. Whenever it starts to rain, the motor is activated, turning a pulley that reels in a wire cable that closes a top-hung Velux window from near-horizontal (open) to 45 degrees (closed). That's it. The window stays shut until you wake up, check that it has stopped raining, and then re-set it as needed.
Everything else is manual - attaching the unit to the bottom of the window frame, plugging in the power supply, opening the window, reeling out and attaching the cable to the bottom of the window, and placing the rain sensor outside the window.
I would like to be able to simultaneously auto-close up to three identical windows in this way, so it would be great to have people's thoughts on how I could approach this at a conceptual level. The windows in question fall within a linear footprint of about six metres, and running cables between them would be possible but a fair amount of work. There is a reasonable WiFi network in that part of the house, but I would prefer to keep things hard-wired for reliability and because of my limited Arduino expertise. My thoughts so far:
- Build two more self-contained units like the one I have, and deploy them as needed. This would give maximum flexibility but wouldn't be very user-friendly. (BTW I do not want them to be permanently attached to the window frames, and I'm not happy relying on cheapo rain sensors remaining permanently in the open air)
- Place a single permanent rain sensor outside, and plug each unit into it via a socket in each window frame. This avoids having to fiddle about with installing and removing a dedicated sensor every time I set up each window. I would probably have to use a more durable (gold-plated?) sensor if it was to be placed outside permanently.
- As for 2. above, but also have single central Uno, which would send an activation code to a motor driver in any units that were connected (again, via a plug in the window frame). This would have the limited advantage of making each unit a bit smaller and cheaper, and would mean I only need to update a single Uno if I tweak the code (eg motor speed, rain sensitivity) - but these are not major considerations.
Cost is not really an issue (for comparison, it would cost over £1,000 to retro-fit a single new auto-close Velux), and I would have no problem scrapping some of the work I have done to date. My mechanical and general DIY skill levels are very high; my electronics skills those of a competent hobbyist; and my Arduino programming skills are cheerfully amateur.
Any comments/suggestions on the overall concept design, anyone? Feel free to be creative - I'm looking for user-friendly, practical ideas rather than detailed technical/coding solutions at this stage.