While out shopping for bed’s with his better half, [Shane] tried out one of the more expensive, all “bells and whistles” included models. While the aforementioned featurees were impressive, one stood out: motion controlled underlighting for when you had to get up in the middle of the night.
Knowing that this feature would be easy to replicate [Shane] went about making his own version. Using PCV pipe to make the framework for the LED’s a 9 volt DC power supply, and a list of electronic components all that was left to figure out was the motion controls.
PIR motion sensors are the natural choice and its simple enough to hook them up to the micro of your choice and bang out some code. It’s just as simple to hard wire them into a circuit skipping the added cost of the micro and complexity of the software.
The two PIR sensor outputs are wired though a diode OR gate, to a potentiometer to control sensitivity, and then to a pair of NPN transistors to ultimately control power to the LED strips. Now they have motion controlled night lights for their bed when nature calls in the middle of the night.
…This idea is genius. Truly and purely genius.
My cats would agree. They would also add “diabolical”.
This may not be a good idea if you have cats :)
this is definitely not a good idea if you have cats. I do, and I had leds under the bed, till the day they chewed it all.
Years ago I stayed at a hotel that did this. Lit up various small lights as you walked around (if the main light was off). Always wondered why it wasn’t more common (aside from cost).
Local supermarkets have this in their fridges now. The lights inside are only turned on when someone trips the PIR sensor when walking in front of them. I figure it’s to reduce the heat load inside the fridge; would have been more useful before they switched to low watt LED, but eh, every bit counts I suppose.
Of course these: http://www.dhgate.com/product/9pcs-led-light-bulb-for-wall-socket-230v/161872020.html are pretty common and cheap now, takes most of the fun out of DIY. I’ve got a few around the house to assist with night time meanderings.
I think it did not make sense to do this before LEDs because fluorescent lights have a short life if you flip them on/off often. Maybe the bulb cost was not worth the energy cost.
Speaking of cheap LEDs with PIR / dusk switch: i have found quite a few that burn about the same amount of energy whether on or off. The reason being that they used a shunt transformer less power supply.
Fluorescent lighting makes more sense for not doing it before.
It is a kinda fun “haven’t I seen this in countless SF & horror movies” seeing the lights click on one by one as you walk down the aisle.
I once saw a Sony CD player where the power switch was on the low voltage side, not mains, of the transformer. Kept it nice & warm for the cockroaches.
i just spent a week in a hotel with this “feature”…every time I stuck my leg out over the side of the bed (i.e. when I kicked the covers off to cool my toes, with no intention of getting up) the bloody things came on.
Poor implementation of a good idea. :(
ive had this for a year i just used a rope light i hav and it works like a champ but very nice
i keep my router and cable modem under my bed (thats where the cable jack is), they have enough leds on them to do the same job.
Neat project. I’d go with red LEDs though. Less likely to wake you up. White is harsh and contains blue light which could leave you with trouble getting back to sleep after returning to bed.
Not to mention that red light doesn’t have such a great affect on your night vision, meaning that when you escape the confines of your bed and make it to the next room where the lights are still off you’re more likely to be able to see where you’re going.
Amber might be another useful option that is fairly night-vision friendly.
I have just put a low wattage LED “can lamp” in the kitchen and bathroom, lets me walk around pretty well but then I have good night vision. I’d agree on avoiding blue light, green or red are better (green’s been used more recently, red is old school :))
Why that many LEDs? In my experience, just one 5mm white LED is super bright in the middle of the night.
A strip of dim LEDs is better than a single LED (diffused vs point source and all that), I guessing the brightness was just for demonstration.
You don’t really need a lot of light to help you move about though. Clipping the top off a LED helps to throw light in all directions.
Yeah, based on using a 9V battery pretty much. However, it’s a waste of power that the author did not put 2 LEDs in series.
I’m currently doing a similar setup with ws2812 led strip and user settable colour and brightness via pots.
Is the word PCV a spelling mistake? Anyway, great post though.
Considering the litany of other affronts to the English language in this post, I would assume so.
Nicely done!
I have some glow-in-the-dark adhesive-backed vinyl stickers on the feet of my chair and a few other things that move around in my bedroom. They end up pretty dim towards the end of the night, but still enough to see. Low tech solution, but not as badass as motion detected LEDs. I agree with the comment above, maybe try RED led’s to preserve night-vision and avoid melatonin disruption – or whatever it is that white or blue light does (too zzz to google).
Thought about doing the same…. but ended up buying a commercial battery powered one. Still hacked it with RC to turn on/off slowly.
I have to appreciate the article: “Something bright enough to help you find your way, but dim enough as to not wake the blanket-stealing snore-machine sleeping next to you (To My Wife: Baby, your snores are like lullabies. Truly.)”
+1
Nice touch getting Randal Munroe to do the CAD work. }:~)
Damn. When I saw the “CAD drawing” I rushed to the comments to write this but you beat me to it.
This sounds cool, but I guess the bed in question is not open at bottom — in other words it sits on a box on the floor.
I probably would not stub my toe on any of the beds in my house, since there is 2 or maybe 4 inch gap at the bottom.
“While out shopping for bed’s”
“the aforementioned featurees”
“PCV pipe”
“its simple enough”
Honestly amigo, proof-read your posts! This sort of thing is at best an embarrassing typo and at worst a jarring mental speedbump.
Great idea and excellent execution! Thanks for sharing!
Nice idea, i’d want a softer light, too bright for me in the middle of the night!
Have been doing this also for a few years, my blog with design files and code. http://tobyrobb.com/wordpress/?p=757