Fairies Don’t Poop
So if you’re after a weekend project, and you need to placate tiny humans, you could do a lot worse than a Fairy Cottage. A fairy cottage is like a dolls house except you don’t play with it, you put it somewhere and invite fairies to come and live in it by being quiet and going to sleep. I’ve taken the concept and made into a night light using an Arduino and a set of addressable LEDs. it’s powered by a USB wallwort and each room will randomly light between 5 and ten minutes. Theoretically it might not light at all, but statistically it should turn on at least one room after a while. Here it is: read on for build instructions OK, so the cottage itself is from here http://www.makecnc.com/berea-contrast-house.php and is really well designed and detailed. The zip file has versions for lasercut and CNC and for different thicknesses of material: 5 out of 5, would download again. The only thing i would say is that if you’re using cheap wood (and i would) its not going to hold up to much abuse. The roof is supposed to lift off but its a pain to get on and off and i broke a bit just trying to get it to sit straight. YMMV Anyway, you’ll want to take the DXF laser file of your choice and then split it into 600x400 pages so you can cut it on the laser cutter. you’ll end up with this that’s 5 sheets of wood, but i think you could get it down to 4 if you were a bit better than me with your placement. If you use the cheap bunnings ply that’s $20. A note about the roof, i used 60mm/s at 15% for the tile pattern but because the roof has a lot of repeated lines it cut too deep and warped the roof. Even though it’s sooooo much slower, you might be better off using engrave. ok, start making, you need to glue the windows, everything else is locking hook tabs. i’ve drilled a hole for the usb cable to poke through. it’s really hard to assemble. i’d start with the inner walls, then the inner floor, then the outer walls, but at some point you have to force one end. The windows are glued together, i filled a teaspoon with PVA and then dipped my finger in and touched the wood as required. The ‘glass’ is grease proof paper which worked great. I had a bit of APA102 addressable LED strip left over from another project. I threaded it through each room. Some pillow stuffing material is used for chimney ‘smoke’. I did try lighting the smoke but by the time the led was bright enough to light the smoke it also lit up the chimney so it looked weird. Fairy Cottage or Portal to Hell, the LED brightness is important. With everything constructed i left the last roof panel off while i worked on the code. The Code So you’ll find the code here, and it’s also a great place for any questions you may have (it’s the Robodino mailing list) https://groups.google.com/forum/#!topic/sydney-hackspace/gS0tefDlLKI I use the polou led library https://github.com/pololu/apa102-arduino these strips are like the ws2812 except they are faster and (imo) easier to use. they do require one more pin than the ws2812. I played around with both the high level and low level library interface, in the end i found the right brightness and used the high level which is simpler, and each room has a different colour light. here’s the flow: power up: all lights off; create a random seed based off an unattached analog pin 1. wait between 3 and 5 minutes 2. randomly pick a room 3. either turn the light on or off in that room (if the light is already off, it can still choose to turn it off; in which case no change is perceived). 4. goto 1 There are two exceptions, The toilet turns on for 30 seconds only, then turns off. …Because faeries don’t poop. In a future version i might program one of the LEDs to act like a tv, throwing out random colours around 15fps but i need a bit of time to work on that. Other thoughts: you could make this into a proper dolls house by having the roof hinge and run the wiring in the wall cavity. Laser cut holes in the walls for the led to shine through. you could use a servo with a fairy silhouette stuck to the arm that would cast a shadow against the window every so often. I tried cutting out a fairy shape and hanging it in the room but it just looked like someone had hung themselves, not really what i was going for.