Bathroom smart door

A nice way to protect your and your guests' privacy with a red led that flashes when the door is closed!

The objective was to put, instead of the key, the circuit and the battery inside the door, leaving visible just a small magnet.

The use of the microcontroller and the related code allow to minimize the current consumption, which is about 3 mA for 30 ms with LED on, about 5 µA with LED off, and zero when the magnetic switch is open. The battery will therefore last hundreds of hours.

In case you don't like the idea, a very small and low-power LED flasher will reamain anyway!

I've attached some pictures, schematic, the sketch and the firmware of the project and a short demo video.

Best regards,
Anto

Project Elements

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Schematic

Software.zip (ZIP)

Sketch, firmware, schematic

Video.zip (ZIP)

Demo video

Discussion (3 comments)

Ton Smits 8 years ago

Really nice project !
As I am interested in this low power flashing circuit (for another purpose),
I would like to build a few.
Now I face the "challenge" how to get the HEX file uploaded to the ATTINY45.
After googling an hour, I find all kinds of solutions using Arduino boards.
But for now, it would be sufficient for me if I could connect a "convertor" between my Windows pc and the ATTINY45, and upload the HX code file.
Does something like this exist ?

anto 8 years ago

Hi Ton,
thanks for having shown interest to my project!
The easiest way I know to load an HEX file into an ATtiny45 is through a cheap USBasp and its related software; here's an example of it:

http://www.ebay.it/itm/3-3V-5V-USB-ISP-USBASP-Programmer-Downloader-Cable-for-Atmel-AVR-ATMega-51-TE141-/131612550562?hash=item1ea4b825a2:g:Vr4AAOSw9VZXOVkW

Personally, I like using AVRDUDE and its GUI AVRDUDESS as softwares, which are easily downloadable at the following links:

http://savannah.nongnu.org/projects/avrdude

http://blog.zakkemble.co.uk/avrdudess-a-gui-for-avrdude/

I don't know how developed your skills are, but I can gladly give you these inputs, in order to enable you to at least start working, hoping they are useful!
Regards,
Anto

Anto

1 Comment(s)

Manfred J. Baulig 8 years ago

How to close the door, when a circuit is is inserted in the keyhole?

anto 8 years ago

Hi Manfred,
the main objective of this project it's being able to avoid the use of the key! It is the light coming from the keyhole that shows someone's presence in the bathroom.
Thanks for showing interest.

Regards,
Anto

1 Comment(s)

M J Bauer 8 years ago

Maybe I missed something, but if the door is closed, it is obvious that the door is closed. You don't need a flashing LED to tell you that the door is closed. A more useful arrangement might be for the LED to flash only if there is somebody inside the room who wants privacy. The device could be activated by a manually-operated latch with two positions: "vacant" and "occupied", like a public toilet.

M J Bauer 8 years ago

Hi Anto. OK, now I get it. Thanks for your kind comment on my project too. Cheers, Mike

anto 8 years ago

Hi MJB,
You are right but so am I!
I did not specify that at home we usually leave the doors open or ajar. Therefore what I needed was only a system that enables a guest, an elderly person or a child, for example, to know that simply by closing the door completely, the LED will flash automatically as a request of privacy, without the need of any key or other manually activated devices.

P.S. Congratulations for your musical project, very interesting and well described, I gave it the highest rating!