When the first two prototype ingredients listed are paperclips and Post-it notes you know it’s going to be good. The problem: one shower stall at work with numerous co-workers who bike to the office. The solution: a occupancy monitor that is smart enough to know that someone is actually in the room. You know what we’re talking about, a sensor that knows more than whether the door is open or closed. [James] got wise and built a sensor to monitor whether the door is bolted or not. We think this method is far superior to motion-based systems.
This uber-smart sensor is simply a pair of paperclips anchored on a rolled Post-it note substrate and shoved in the receiver on the door jamb. When the bolt is locked from the inside it pushes the paperclips together completing the simple circuit. This is monitored by a Spark Core but will work with just about any monitoring system you can devise. What we’re trying to figure out is how to ruggedize the paper-clip hack which we can’t think will perform well for very long. It looks like there’s room to bore out a bit more inside the receiver hole. Perhaps leaf switch with a 3D printed mounting bracket?
Oh, and kudos on the Ikea food storage container for the enclosure. That’s one of our favorite tricks for hacks which are installed for the long-run.
Mike, this hack had you at postits and paperclips.
How about a:
1 Microswitch
2 Reflectance by painting the end of the bolt
3 Photo-interupter
4 Or a simple conductive path created by the bolt in contact with a bic pen spring attached to a wire in the reciever hole.
But don’t touch my Swingline model 747, I’ll burn this place down.
None of this corrosive crap! Only sealed magnetic sensors will hold up. Reed switch or hall effect sensor.
What? People not wanting to shower an hour earlier at home? No jocks wearing girdles please.
This is for people who CYCLE to work.
Cycling to work makes people SWEATY.
Sweaty people STINK up the office!
Oh hey Wonko, nice to see you here
Don’t recall your name. I may not be the Wonko you’re thinking of.
That old guy over there said “You’re not the Wonko we’re looking for”.
“Cycling to work makes people SWEATY.”
Then they are doing it wrong..
I ride to work. I am not in a hurry, so no sweat. Always wearing street clothes not jock stuff. The one thing needed at work is a fan to dry off for 10 minutes or so.
The air in a office is never right for those first 10 minutes.
Use an inductive or capacitive prox switch. They are generally sealed to IP65 so they will take whatever you can throw at them.
Paint the bolt with conductive ink and have it connect two painted points on a piece of foam board inside the receiver hole
Bolts are conductive by design, no need for conductive ink.
I wouldn’t say bolts are conductive by design. Few bolt designs will have electrical conductivity as a primary requirement. You can’t rely on that.
The paperclips lasted longer than the shower room! After 7 months they were still working great. The office has been gutted and is being refurbished so I’m using the hardware for my Christmas tree now: https://unop.uk/hardware/spark-core-xmas-tree-lights-10-minute-hack/
My first attempt was to use two springs but the bolt wasn’t conductive so would need modifying (and it’s not mine). I hadn’t expected to use the paperclip rig beyond the prototype stage but it performed so well that I kept it for version 1. It survived being ripped out for the build and for demoing at events. The electrical connections are just old school wire wrapped too. Damp isn’t an issue as it’s not exposed to the room when in use.
I’m planning an even better version 2 for the new office but will need to see what the new doors look like first. These comments have some really useful ideas!
wow..people have some weird ideas about switches. Those paperclips, while ghetto in the extreme, will probably last plenty long. The main reasons switches fail are abrasion of the contact surface or the contact surface being destroyed by arcing. Being made of steel, abrasion of the surfaces will take a LONG time. Being used as a simple, low amperage contact switch in a microcontroller circuit, arcing should be quite minimal, resulting in long lifetimes again.
you would be amazed at how little of a usable contact area it takes to close a low amperage, low voltage circuit enough to trigger a microcontroller input.
What? Nobody mentioned putting a wireless camera in the shower to see if it is occupied?
I thought this problem was solved with the advent of the internal combustion engine… ;)
Why not just shower together, great for office morale.
Getting things done! Great hack :-) James you rock!
Not sure how knowing the shower is occupied stops others from stinking up the place. Are they made to wait outside the building until the shower is free?
Logical next step… Red/Green traffic light system mounted to the outside of the office system showing shower occupancy. Cyclists can then continue around the block until they are green to shower :)