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"Toilet In Use!" Traffic Sign for my Workplace
11 years ago
I recommend reading the original version here on LiveJournal
I happen to work in the Tech/IT/Project administration of the company I work for. Our department shares the floor with some other departments. Overall, we are quite a lot of people. And there's just one toilet on the floor. Okay, there's a second one but that the one for ladies. Most of my colleagues happen to be coffee addicts. Some are of the heavily addicted kind. By now you may start to understand the quandary that arises from this specific situation. Yep, a frequently occupied toilet which in return means that each of us often walk to the toilet when it's already in use. The problem isn't exactly that you have to check later again - or wait. The problem is that most of us head downstair to the second floor. This inhabits a potential risk for meeting other colleagues. Colleagues will see us and will remember that there was something they wanted to ask us about. We're doomed. In most cases we won't see our own again workdesk before half an hour ago. Which disturbts the train of thoughts in regard to our own work.
It's a problem. I fix problems. That's why I got the nickname Fix it Fox at work. Eventually on a Friday about two months ago most of my colleagues were not in but attending an external meeting. I took the opportunity and finally assembled the Toilet Traffic Sign I've been building at home during the summer every now and then when having a minute of free time. Looking for traffic sign housings? Ebay is your friend. This one was cheap because it orgially existed of three elements. One was completely damaged. Sadly it was the red element. But organge works as well.
There's not much to say about it. The light bulbs got replaced with cheap LED-clusters from ebay. The whole system is powerd by a small 5V/1A Wall Plug Power Supply. The PIR Sensor was salvaged from an old Solar Garden Lamp (water and frost damage). A ATTiny25 Mikrocontroller was used to bring it alive. The CPU clock is generated by using the internal RC Oscillator with approx 8MHz. The Timer/Counter0 unit runs in CTC Mode and creates an IRQ every 50ms. Timer/Counter1 generates a 35KHz PWM signal for a smooth LED fadeover between orange and green.
The Software is kept simple as well. With each IRQ from Timer/Counter0 the "PIR Input Pin" is read. The PIR Sensor itself, which is connected to it, generates a 100ms long puls each times it detects movement. The µC can't miss a hit. An impulse turns the lamp from green to orange (Toilet occupied) The read impuls sets a 16Bit timer to value 1800 (20 Timer IRQs/s * 90s) and is decremented with each IRQ from Timer/Counter0. While the counter is decrementing each new impulse will set the counter back to 1800. When the counter hits 0 (after not receiving an signal from the PIR Sensor for 90 seconds) the light fades back from orange to green (oilet free). There are two reasons for the delay: making sure the toilet is really free. Some poeple tend to sit quite still, which makes it harder to detect them. It helps to avoid the false assumption of a free toilet. From two months of operation I can tell: 90 secods works like a charm. Also, it help to aerate the room at least a bit after use.
Traffic Sign and PIR-Sensor installed
• Sensor Mounted
• Light Sign Mounted
Some impressions from the construction
• Programming Adapter
• Controllerboard Topside
• First Test
• Controllerboard Installed
I happen to work in the Tech/IT/Project administration of the company I work for. Our department shares the floor with some other departments. Overall, we are quite a lot of people. And there's just one toilet on the floor. Okay, there's a second one but that the one for ladies. Most of my colleagues happen to be coffee addicts. Some are of the heavily addicted kind. By now you may start to understand the quandary that arises from this specific situation. Yep, a frequently occupied toilet which in return means that each of us often walk to the toilet when it's already in use. The problem isn't exactly that you have to check later again - or wait. The problem is that most of us head downstair to the second floor. This inhabits a potential risk for meeting other colleagues. Colleagues will see us and will remember that there was something they wanted to ask us about. We're doomed. In most cases we won't see our own again workdesk before half an hour ago. Which disturbts the train of thoughts in regard to our own work.
It's a problem. I fix problems. That's why I got the nickname Fix it Fox at work. Eventually on a Friday about two months ago most of my colleagues were not in but attending an external meeting. I took the opportunity and finally assembled the Toilet Traffic Sign I've been building at home during the summer every now and then when having a minute of free time. Looking for traffic sign housings? Ebay is your friend. This one was cheap because it orgially existed of three elements. One was completely damaged. Sadly it was the red element. But organge works as well.
There's not much to say about it. The light bulbs got replaced with cheap LED-clusters from ebay. The whole system is powerd by a small 5V/1A Wall Plug Power Supply. The PIR Sensor was salvaged from an old Solar Garden Lamp (water and frost damage). A ATTiny25 Mikrocontroller was used to bring it alive. The CPU clock is generated by using the internal RC Oscillator with approx 8MHz. The Timer/Counter0 unit runs in CTC Mode and creates an IRQ every 50ms. Timer/Counter1 generates a 35KHz PWM signal for a smooth LED fadeover between orange and green.
The Software is kept simple as well. With each IRQ from Timer/Counter0 the "PIR Input Pin" is read. The PIR Sensor itself, which is connected to it, generates a 100ms long puls each times it detects movement. The µC can't miss a hit. An impulse turns the lamp from green to orange (Toilet occupied) The read impuls sets a 16Bit timer to value 1800 (20 Timer IRQs/s * 90s) and is decremented with each IRQ from Timer/Counter0. While the counter is decrementing each new impulse will set the counter back to 1800. When the counter hits 0 (after not receiving an signal from the PIR Sensor for 90 seconds) the light fades back from orange to green (oilet free). There are two reasons for the delay: making sure the toilet is really free. Some poeple tend to sit quite still, which makes it harder to detect them. It helps to avoid the false assumption of a free toilet. From two months of operation I can tell: 90 secods works like a charm. Also, it help to aerate the room at least a bit after use.
Traffic Sign and PIR-Sensor installed
• Sensor Mounted
• Light Sign Mounted
Some impressions from the construction
• Programming Adapter
• Controllerboard Topside
• First Test
• Controllerboard Installed
I would expwct whole automated signal and control system.
1. GREEN - nobody there, ready to use
2. RED - in use do not disturb
3. AMBER - toxic atmosfere presend, room venting and room atmosphere conditioning in progress.
Well you need to sort that 3rd step in your control logic then.
You forgot:
- WARNING: short on toilet paper
- PROBLEM: out of toilet paper
Well we are not in JAPAN, here some things are done in old fashion way
Ne Spaß beiseite: Das ist ja mal eine witzige Idee. Zum Glück haben wir solche Probleme nicht auf Arbeit.