iPotti™ Released!

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iPotti™ 1.2 bathroom status device

iPotti™ 1.2 bathroom status device

So, we have this issue at the office with our single-person bathrooms. We have one “m” bathroom and one “w” bathroom. We have 40+ people in the office. Many people who sit out-of-sight from the bathrooms often walk all the way across our office only to find out that someone else has beaten them to the potti.

To solve this problem, I took a Make Controller from MakingThings.com, wired a couple of Vishay TEMT6000 ambient light sensors (photo transistors) to it, then wrote a Mac desktop app to sit in the status bar to show everyone the status of the pottis. I call it, “iPotti™” and it works awesome!

At the heart of iPotti™ is the Make Controller. It’s an Atmel Sam7 ARM microcontroller with the Make Interface Board stuck to it. The Interface Board has Ethernet, USB, power and breakout headers for the pins of the microcontroller. I wrote a slim little piece of firmware for it that simply broadcasts UDP packets with the status of the pottis. It broadcasts a packet about every couple of seconds.

At the receiving end of the iPotti™ system is a little Mac OS X app designed to sit up in the OS X status bar:

iPotti™ in the OS X® Status Menu

iPotti™ in the OS X® Status Menu

iPotti™ Status Menu - Men Busy

iPotti™ Status Menu - Men Busy

The letters are green when the pottis are available. They turn red when the lights go on inside the bathroom. Lights are the whole trigger in this device. I didn’t want to get into sensing AC current in the light wiring or tapping into the switches. This was the cheapest and easiest to get done quickly and without forking out too much coin.

The status menu item has a drop-down menu, as well. It’s how you quit the app or check the About dialog:

iPotti™ Menu

iPotti™ Menu

The About dialog is pretty simple, but it turns out to be indispensable, since I’ve now released about three updates to the client software.

iPotti™ About dialog

iPotti™ About dialog

The sensors see ambient light like the human eye does. I mounted them up above the bathrooms and oriented them to look through little vent holes in the lighting canisters. The light cans keep themselves pretty cool, so there shouldn’t be any worries about melting the little sensor thingies. (Read on to see the sensors and their PCBs.) Here is what they look like mounted near the ceiling light cans:

iPotti™ light sensor in position

iPotti™ light sensor in position

The sensors are spliced to 4-wire alarm cables that run back to the main iPotti™ server. The two cables join into a single RJ-45 connector (same one used for Ethernet, looks like a big phone jack connector) and then snap into a port in the side of the iPotti™ device box.

Another sweet technical feature of the installation is that our office uses IP phones that get their power from the Ethernet switches. It’s call, “POE,” which stands for Power Over Ethernet. We bought a little Cisco®/Linksys® POES5 5-Volt splitter that happened to have the proper little coax power connector AND it was the proper polarity, so I didn’t have to do anything to hack it together. Here’s what it looks like connected up, powering and communicating (outside of the case, of course):

iPotti™ powered over Ethernet

iPotti™ powered over Ethernet

Inside its case, the iPotti™ looks like this:

iPotti™ put together in the case

iPotti™ put together in the case

The Make Controller doesn’t fit perfectly in this spare project box I had, but it’s good enough for a device that nobody will ever see (hardly ever, anyway). The two white cables protruding from the left side of it are being replaced with the RJ-45 jack for the sensors. Originally, in version 1.0, the cables went right inside the case, wrapped around a screw post for strain relief, and then jacked into the controller.

The latest incarnation (the one that is live and connected now) uses some recovered USB ports from some circuit board I had in my junk pile. I took the ends off of two old USB cables and spliced them onto the ends of the bathroom light sensor cables. I should have done that from the start, but I was lazy and anxious to get this thing up for testing. Now, I can easily disconnect it and update it or maintain it.

The only fab I had to do was on the sensors. They are surface-mount (SMD) and they require a resistor, so I made little PCBs for them using my usual toner-transfer process:

Spare or reject sensor PCBs

Spare or reject sensor PCBs

Fully assembled, they each look like this:

iPotti™ ambient light sensor

iPotti™ ambient light sensor

The real trick will be getting people to remember to turn of the lights behind them. We’ve had signs up for the for the longest time to remind people. Occasionally, someone does forget. Overall, the solution works well.

Lessons learned from this project: A little Make Controller doesn’t fair well as a web server when 40+ workstations are hitting it every two seconds. The 1.0 version of the system had the iPotti™ main device set up as a web server and the iPotti™ app hit the server every couple of seconds. This was painful and dumb. I chose that over UDP out of laziness and fear of the unknown (I had never set up UDP broadcasts on the Make Controller’s lightweight IP stack AND I hadn’t done it yet in my Cocoa [Mac OS X] development adventures). Turns out that UDP was stupidly simple to implement on the Make Controller AND for OS X. I should have done it from the get-go.

Here are some other photos of the installation and a famous red box…

Do not lick soldering irons

Do not lick soldering irons

SparkFun box!!!

SparkFun box!!!

Designer and his new creation

Designer and his new creation

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iPotti™ Released!, 5.0 out of 5 based on 1 rating

20 Comments (+add yours?)

  1. Office Device Lets You Know When to Go | Boomeroo Web Resources
    Mar 09, 2011 @ 11:20:14

    [...] Frey writes in to announce the iPotti, developed using the Make Controller: So, we have this issue at the office with our single-person [...]

  2. Office Device Lets You Know When to Go | LED Life
    Mar 09, 2011 @ 11:49:01

    [...] Frey writes in to announce the iPotti, developed using the Make Controller: So, we have this issue at the office with our single-person [...]

  3. Stay Informed of Your Office’s Bathroom Sitch With iPotti [DIY] | MacBook Laptop | Apple Mac Laptops | Apple Macbook Laptop
    Mar 09, 2011 @ 20:01:00

    [...] (looks like it involved a lot of time and awkward obsessiveness) check out the official site. [iPotti via [...]

  4. Stay Informed Of Your Office’s Bathroom Sitch With iPotti | Gizmodo Australia
    Mar 09, 2011 @ 22:23:39

    [...] (looks like it involved a lot of time and awkward obsessiveness) check out the official site. [iPotti via Make] [...]

  5. Stay Informed of Your Office’s Bathroom Sitch With iPotti [DIY] | That Soviet Guy
    Mar 10, 2011 @ 01:41:34

    [...] (looks like it involved a lot of time and awkward obsessiveness) check out the official site. [iPotti via [...]

  6. Conoce en todo momento el estado de los baños gracias a iPotti - Gizmodo ES - The gadgets weblog
    Mar 10, 2011 @ 06:31:00

    [...] cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  7. Conoce en todo momento el estado de los baños gracias a iPotti « BN
    Mar 10, 2011 @ 07:58:52

    [...] A pesar de que es sistema permite conocer el estado de cada uno de los baños no evita que mientras llegas alguien se te adelante, por ello yo le recomiendo a su creador un sistema de reservas y si las cosas se ponen feas un cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  8. Gizmodo ES | Linkeando
    Mar 10, 2011 @ 08:42:13

    [...] A pesar de que es sistema permite conocer el estado de cada uno de los baños no evita que mientras llegas alguien se te adelante, por ello yo le recomiendo a su creador un sistema de reservas y si las cosas se ponen feas un cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  9. iPotti Lets You Know When The Loo Is Alone [DIY]
    Mar 10, 2011 @ 11:03:00

    [...] (iPotti via Make) [...]

  10. iPotti Lets You Know When the Throne is Vacant - Technabob
    Mar 10, 2011 @ 11:19:14

    [...] StuffAndyMakes] Next Post » « Home Comment » Subscribe to [...]

  11. iPotti Lets You Know When the Throne is Vacant | Boomeroo Web Resources
    Mar 10, 2011 @ 11:31:13

    [...] [via StuffAndyMakes] [...]

  12. Conoce en todo momento el estado de los baños gracias a iPotti | Ultimos Avances
    Mar 10, 2011 @ 14:07:56

    [...] A pesar de que es sistema permite conocer el estado de cada uno de los baños no evita que mientras llegas alguien se te adelante, por ello yo le recomiendo a su creador un sistema de reservas y si las cosas se ponen feas un cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  13. Pulse on Techs » iPotti Lets You Know When the Throne is Vacant
    Mar 10, 2011 @ 16:31:28

    [...] [via StuffAndyMakes] [...]

  14. iPotti te avisa cuando el cuarto de baño está libre
    Mar 10, 2011 @ 23:01:33

    [...] Más info y fotos aquí: link [...]

  15. Stay Informed of Your Office’s Bathroom Sitch With iPotti [DIY] | World's Greatest T-Shirt
    Mar 11, 2011 @ 00:13:25

    [...] (looks like it involved a lot of time and awkward obsessiveness) check out the official site. [iPotti via [...]

  16. iPotti Lets You Know When the Throne is Vacant « Gadgets for Men
    Mar 11, 2011 @ 04:32:41

    [...] [via StuffAndyMakes] [...]

  17. Conoce en todo momento el estado de los baños gracias a iPotti | Te Posteo
    Mar 23, 2011 @ 03:27:01

    [...] A pesar de que es sistema permite conocer el estado de cada uno de los baños no evita que mientras llegas alguien se te adelante, por ello yo le recomiendo a su creador un sistema de reservas y si las cosas se ponen feas un cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  18. Conoce en todo momento el estado de los baños gracias a iPotti | Noticias de tecnología
    Apr 17, 2011 @ 11:02:23

    [...] A pesar de que es sistema permite conocer el estado de cada uno de los baños no evita que mientras llegas alguien se te adelante, por ello yo le recomiendo a su creador un sistema de reservas y si las cosas se ponen feas un cursillo a lo Spy vs Spy para neutralizar a tus oponentes en la carrera retretil.— Dani Burón [iPotti] [...]

  19. meltmedia Hack Day July 2012!
    Aug 01, 2012 @ 22:04:19

    [...] like meltmedia, we may even add more interactive hardware to the offices, like a new edition of iPotti! VN:R_U [1.9.18_1163]Rating: 0.0/5 (0 votes cast)VN:R_U [1.9.18_1163]Rating: 0 (from 0 [...]

  20. Engaged or vacant? iPotti monitor knows when to go | Microcontrollers, Sensors | Gadget Master
    Apr 29, 2013 @ 20:53:18

    [...] he set about creating a monitoring system that would help avoid useless trips – he dubbed it iPotti, the box for which carries the slogan ‘ know when its time to go’. It should be [...]

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