Smart Curtain Opener/Closer

thingiverse

I dont want to spend hundreds on smart curtain closers, don't want to have to charge them/replace batteries and don't need them to be wifi, so designed this motorized curtain closer that only needs the following : 10-20ft [beaded chain](https://www.ebay.com/itm/221319132229?hash=item3387a5f445:g:i4MAAOSw-vlVlLNr) (depends on width of curtains) (~$10) 1x [smart outlet](https://smile.amazon.com/gp/product/B092DBFFBY) (~$10) 1x [12v geared motor](https://smile.amazon.com/gp/product/B072N84JX7)(~$10) 2x [endstops](https://smile.amazon.com/dp/B07HKQB2J2)(~$5) 1x [12v wall wart](https://smile.amazon.com/gp/product/B07VBR327W) (~$5) 1x 5v standard USB charger (free?) 1x [5v dpdt relay](https://smile.amazon.com/dp/B079FGPC9Y) (~$5) 10-20ft [20-22 awg wire](https://smile.amazon.com/dp/B00WD017GQ) I suggest as it seems to carry enough current, but you can use anything (~$10) So a total of 50-100 depending on if you have some of this already. The general workflow - You install this at the top of your curtains, with the motor on one side and an idler on the other so there's a loop of beaded chain. - Power (12v) is always applied to the circuit, turning the motor until an indicator on the beaded chain reaches a limit switch, - Using a smart switch, you toggle power (5v usb) to the dual dpdt relays, switching the polarity of power (12v) going to the motor, reversing it's direction. - Using a [clever circuit](http://forum.arcadecontrols.com/index.php?topic=149294.0) you can circumvent the first limit switch, driving the chain in the opposite direction until it hits another limit switch. - This means the curtains can only ever be fully open or closed. Following the flow of power 1. A 12v psu is plugged into the wall, and the output leads into the dual dpdt relays 2. A 5v usb adapter is plugged into the smart outlet. Use a [usb to barrel cable](https://smile.amazon.com/gp/product/B07GN3XQ7N) + [barrel pigtail](https://smile.amazon.com/dp/B072BXB2Y8) or just cut and strip a usb cable and apply power to the dual dpdt relay module's input 3. A long cord of ethernet cable carries power from the output of the DPDT relays up to the geared motor where all the printed parts and mechanical components are. Ethernet has 8 wires, so use 4 pairs to input +/- and -/+ into the motor. Again, refer to [this site](http://forum.arcadecontrols.com/index.php?topic=149294.0) where thy use this idea with a dpdt rocker, but we can apply the same thing to a dpdt relay. In both cases, the 12v input goes to the center pole (pin 2), and in one configuration, + and - come out from pin 1 on one of each of the relays. With power applied, the relay switches and pin 3 should apply the opposite polarity. I won't try and walk through the exact flow of power, but again, the idea is there is one limit switch on each set of wires (regular and reverse polarity) so that when power is interrupted with one set of wires, the second set of (reverse polarity) wires circumvents this limit switch. I've made a similar device for pull-cord blinds (that changes the angle, it doesn't have the power to lift heavy blinds) Will post that soon.