The Firefighting Windmill

Do you forget to blow out your candles when you leave the house? Forgetful roommates who don't pay for fire insurance? Our tiny windmill is the solution to your paranoia, no tealight stands a chance against its powerful 3" fan.

When a dangerous tealight is detected, the tiny windmill works quickly to alert you with both a visual (LED) and auditory (buzzer) alarm. Simultaneously, the tealight is extinguished by the tiny windmill's tiny fan.

This project was created as part of the Physical Computing course (ARC385) at the John H. Daniels Faculty of Architecture, Landscape and Design HBA in Architectural Studies program at the University of Toronto.

Team Members: Camille Jolicoeur, Line Sato-Bouziri, Matthew Straub

Components

x1 Arduino Uno

x1 mini breadboard

x1 DC fan motor

x1 3" diameter fan

x1 flame sensor

x1 active buzzer

x1 NPN transistor

x1 330Ω resistor

x1 diode

x1 LED (red)

Non-electrical Components

plywood for windmill structure

tealight

Tools and Materials

laser cutter

superglue

sand paper

ruler

Understanding the Logic

The tiny windmill works by using a flame sensor as input for control over three outputs.

1. DC Motor (fan) motion
2. Buzzer sound
3. LED light

When the flame sensor detects a flame (via IR radiation), the led light turns on, buzzer turns on for 2 secs, fan blows for 3 secs and led turns off.

We have made an effort to make the tiny windmill as compact as possible, using only a mini breadboard and minimal components for our required objective. Follow the TinkerCad Diagram to wire your circuit.

We recommend wiring and testing each sensor and actuator one by one. We also suggest opting for shorter wires to avoid bulk, except for the fan, led and flame sensor which require long wires so they can reach their set position.

A link to our lasercut file: https://drive.google.com/file/d/1eobDogYT4iHA6S-3q5CrqVkdQkj9bVB1/view?usp=sharing

You can design your tiny windmill structure however you’d like. We opted for the tiniest, most efficient, possibly the cutest, windmill possible.

This process involved modeling the windmill in Rhino 3D, according to the size of our circuit setup. The 3D model was then prepared for laser cutting and assembled with super glue. It holds the entire circuit and Arduino Uno board comfortably inside. It must be so cozy in there.

If you want to maintain access to the interior components, remember to keep one of your panels unsecured, we opted for the back panel.

Conclusion

Overall we successfully executed our concept of a mini candle extinguisher. Beyond its function, we are also satisfied with the design of its cute and miniature appearance. This project allowed us to explore sensor-actuator and the relationship of mechanisms within a circuit. We learnt the importance of keeping in mind the timing and interplay of multiple actuators for triggers to work properly with each other. While also keeping the circuit as small, efficient, and compact as possible.

Throughout the process we had to ask ourselves a lot of questions. For example,

• how far does the flame sensor have to be from the candle to detect it?
• how high/far does the fan need to be located to blow out the flame?
• how long does the fan need to run for to successfully blow out the flame?
• how to set a suitable delay between input and outputs? i.e. enough time to light the candle, length of buzzer and light sequence in relation to fan

This project was challenging as it involved a lot of troubleshooting with the code as we added more components to our machine. We learnt the importance of timing within a sequence as there were many instances in our process where adding delays eliminated bugs within our code. We often thought something was wrong with our physical wiring or breadboard, but it was a simple error overlooked within the code.

Connecting the DC motor also proved to be challenging at first. Although the code and the wiring were done properly, the fan would not spin when it was meant to. Through trial and error, we learned to not connect the motor directly to the Arduino Uno, and instead use a relay or transistor to regulate its function.

Our flame detector(s), also deteriorated during our experimentation process -- where we actively used a lighter in close proximity to the setup in order to test its function. This issue was solved by purchasing a set of new, high-quality detectors and being cautious about overuse and proximity to the flame.

Lastly, we had trouble with the buzzer component until we switched to an active buzzer. This was caused by interference between the serial read from the flame sensor and the initial passive buzzer.

Like any project, there are some aspects that could be strengthened if other iterations were to be made. If we were to construct this project again or make a second prototype, some formal and mechanical aspects would be more directly addressed: 

1) Hinges: Currently, our windmill has a removable backing which allows for easy and convenient access to the circuit should a component need troubleshooting. This is great for temporary use but if this machine was to be used more frequently, it would not be efficient. For this reason, we would incorporate hinges into the design of the back door, to allow for easy access to the mechanics instead of the door having to balance in place. 

2) Interior structure: Currently, the circuit fits perfectly in the house, with the necessary components being visible while the wiring remains concealed. Although this works well, with continual use, this setup could be problematic as the exterior mechanical components such as the flame sensor, the LED, and the fan fit perfectly in place and don’t have any structure to hold it there. This means that the more it's used, the more the components move around like the LED falling out of the chimney and the flame sensor being pulled into the house. Thankfully, this is a quick design fix that would entail the interior ledges/structural components to be designed in the house and laser cut to appropriately address structural issues. Order and structure is important for troubleshooting, comfort, and organization. The windmill is not just a house, it's a home. 

While this machine truly is useless, we brainstormed ideas for it to be used in a way that may be - a little - useful. If you want to turn this useless machine into a useful one, you just have to increase the delay in the code to the amount of time you want the candle to be on. Once the time is up, the windmill will blow out the candle at the desired time. Now, you have a windmill that will blow your candle after a comfortable hour.