Define 

As you probably already know the world is filled with problems waiting to be solved, and just that was what my class was challenged to do. As a class we were asked to find a problem no matter how big or small, find a solution to it using a circuit, and finally built that circuit. We split in groups and brainstormed different issues in the world, including ones that we have experienced. Bellow is a photo of my groups problem brainstorming sheet:

 

In the end my group ended up choosing to pursue the problem of forgetting to turn off your lights. Leaving my lights on in my room all day is a big problem of mine. I am always rushing out the door in the mornings hurrying to get to school on time and I almost always forget to turn off my bedroom light. Leading to my parents getting mad at me for leaving it on all day or lightbulbs burning out often. Leaving lights on all day is also bad for the environment and raises electricity bills.

Discover/dream

Now that we had figured out our issue, it was time for us to research pre – existing solutions and brainstorm some new solutions. One solution to this problem that already exists is an app that connects to your phone that allows you to turn off your lights from a different location. This would not work as well though if you do not want to have to get a new light switch. Also, if you forgot to turn it off when you left home you would still need to remember to turn it off from your phone.

Some ideas that we came up with included:

• A weight sensor that sensed when you walked out of a room and shut off the light for you
• An alarm that goes off when you leave a room without shutting the light
• A sensor that scans the room and counts down from 10 minutes and if it senses movement it restarts the timer, if the timer gets to 0 it shuts off the light
• And finally, a motion sensor that automatically turns off the light if someone walks past (placed in doorway so if someone walks out the door it turns off)

In the end we discussed it and thought that the weight sensor could be set off by a pet and would not be as accurate, the alarm would just notify you, it would not actually turn off the lights for you so if you are in a rush or you cant hear the alarm it would not work, the sensor that scans the room would be to difficult to code for our grade level and we also would not have the right tools for this one. This left us with the motion sensor that turns off the light when you walk out of the doorway.

Deliver/ explanation of circuit

 

Like I said above, my group chose to make a motion sensor that turns off your lights when it senses you walk past it. To create this contraption we attached a battery pack to a micro bit ( to power it), we then attached the micro bit to wires which led to a relay board (used to transfer any info we coded onto the micro bit and put it into action, its sort of like a switch to turn the lightbulb on and off) this was attached to a lightbulb and another battery ( see photo to the right).

 

 

Coding

Unfortunately our micro bit didn’t have the ability to detect motion and since we didn’t want to make our project to complicated and equal to our grade level, we decided to swap out the motion detection for light detection ( so for our model circuit, bright light = if there was motion or someone walked through the doorway, and dim light = no movement/ the motion sensor not picking up motion). Swapping this out made us able to create a real-life model of the circuit.  To the left is the code on the micro bit, it states that forever, if the light level is brighter than 100 the light will turn off and if the light level is bellow 100 (anything else) the lightbulb will turn on. Bellow is photos of us covering the light sensors and shining a light on the light sensors. When we shone the light on it, the lightbulb turned off, and when we covered it the light turned on.

 

 

 

 

 

 

 

 

Circuit components/how it works

 

The circuit we made is a series circuit since there is only one path for the current to flow. The bigger battery pack to the right of the micro bit powers the micro bit, which then gives intel to the relay board on what to do ( think of the relay board as a big switch for the lightbulb and the micro bit is your finger switching the light switch off and on). The battery in the circuit to the left of the relay board, supply’s voltage and current to the lightbulb when the switch is “flipped on”. (refer to diagram to the right)

 

Debrief

In the end our solution ended up working after many failed attempts. I think this could be a very useful solution to many homes including mine! It could help lower electricity bills and be good for global warming.  I think to make our solution better (and if it was upscaled ) we could make the motion sensor able to detect if someone was walking in or out of a room so that it would only turn off if you leave the room. Other than that I think for my groups grade skill level we created a great solution for a problem that I experience a lot of the time!