Project II – Mirobit (Electronics)

Project Aim

My aim for this project is to utilize the capabilities of the microbit and apply it to an everyday problem.

 

Objectives

• Begin by undertaking (approx.10) tutorials on the BBC microbit website to gain some base knowledge of coding.
• I will then combine the various tutorials to create something new and further develop my skills and knowledge of coding.
• Simultaneous to the previous objectives I must brainstorm specific uses for the microbit for real world application, then design the final product over the course of a week.
• Then I must begin coding/construction of the final product along with any extra parts, I estimate this to take up to 3 weeks.

 Deliverables

• A final report from start to finish displaying the entire process.
• A programmed microbit carrying out the required tasks.
• Produce a mock marketing page for the final product.

Milestones

• Finding an application for the microbit.
• Completion of the design for the final product.
• Completion of the coding of the microbit.

Introduction

In this report I will show a development of skills and explore the limitless opportunities that come with programming and coding of the BBC micro:bit. I will use this device to solve a household problem for many families across the UK. Surging fuel prices, a struggling housing market, and poverty rates – with the ever rising cost of living, mean the need for money-saving options are more paramount in today’s market than ever before. I will aim to provide a device/system that will enable families to easily and unobtrusively save money.

 

Microbit (Getting to grips with the basics)

My first steps with the microbit were simple but necessary, I began by running a program where by the micro:bit would scroll “Hello!” along the 5×5 pixel screen, the second program I ran joined what I had just learnt, programing the screen, with the use of the buttons. The microbit would at rest have a neutral face but when button “a” was pressed it would show a happy face and button “b” would then show a sad face. It was important to do these task so I could gain valuable knowledge of how to organise code and combine two features together. Below you can see the result of pressing the button “b” as an unhappy face is being displayed.

The third program I produced used the temperature sensor within the micro:bit processor along with the screen so that the device could be used as a thermometer. I do not own a thermometer therefore cannot check the results but the readings seemed accurate enough, as in the warm rooms in my house it read 24 and in a cooler place read 16. After performing these basic procedures I moved on to something slightly more complex, and programed a simple game similar to the, dodge the asteroid, games found in arcades. The code spanned over 24 lines (been trying to add a screenshot of the lines of code but the file will not upload to the website not sure as to why). The game starts with the player on the bottom row of pixels and using the “a” and “b” buttons must avoid the falling “asteroids” to survive, one the player is hit the screen will change to a sad face.

After managing to utilise both the screen and buttons features in tandem I decided to try another combination of features, I followed a step by step guide to create a ghost that appears on the screen and using the microphone the user must blow the ghost away. It was important to undertake these tutorials in order to familiarise myself with the capabilities and interface of the Microbit before progressing with this project.

 

 

Identifying the Problem

Within my house there is an ever present problem regarding our heating system, as most rooms sit at an ideal temperature, the ground floor kitchen/lounge always overheats. As a result of this we must leave our windows, in the room, open at all times except at night for safety reasons. The varying temperatures room to room also leads to havoc. With the thermostat being set at varying temperatures throughout the day. To find the specific needs of the solution I will undertake a focus group with my housemates to further identify the problem and narrow down the solution needs. Within this group session I will look at; the solutions main purpose, the products price, the products potential features and the issues I will aim to solve.

After taking on this focus group some project needs and requirements can be drawn from the valuable information gathered. From talking with my housemates about our problem, when asked what is the main problem that needs to be solved the main answer was for an ability to regulate the temperature in the ground floor radiator. This can be achieved through the installation of a radiator thermostat for a total cost of around £20 for the device but with high labour costs of around £100, which all housemates agreed would solve the issue. However after further discussions, a cheaper device that would monitor room temperature across the house in all rooms, via an app or by text, would be of equal use. This is as most tenants spend a lot of time away from home, unable to monitor room their rooms temperature often returning to a sweltering or freezing room. The members of the house would also like a way to set time trips on the heating system too cool the house during the night and provide heating through the day so as to not waste water/electricity.

Thanks to the information gathered during the focus group I am now able to draw in some concrete product needs and requirements that will satisfy my target customers.

 

Project Systems Approach

The approach I will be using for the overview and planning of this project, will be the v-model systems engineering approach. I have chosen this approach as it is simple to follow yet it covers all of the steps in the life cycle of project development.

Needs and Requirements (Concept of Operations)

The Needs

• The product must monitor the temperature of every room in the house individually.
• The want from the consumers requires that the product uses, an app, text or bluetooth link for great accessibility.
• Product is to cost no more than £50 (ideally £35).
• The device must regulate the house heating at specific times of the day/night.

Project Requirements

• To identify the temperature in celsius of the house or room, whether shown directly on device or on smartphone.
• Must use cheap materials and possess a relatively simple design as to ensure the final price of the product is below £50 but ideally around £35.
• Using a predetermined pattern, by the user, the device must adjust the thermostat to the user desired temperatures throughout the day and night.
• To save the user/users money in the long run (over 6 months), with an ideal household heating saving of at least 6%.

 

Data Collection/Background research

To concretely identify the problem using evidence, I have conducted a small data collection of the room temperature for each room in the house. The collection of this data took place between 12 – 3pm whilst the temperature outside was at a consistent 11 degrees celsius. Below you can see the floorplan of our current house with the temperatures annotated the drawing.

In light of the recent escalation of fuel prices, low income households suffering from poor insulation and dated heating technology are most devastatingly hit. Prices hikes of wholesale gases increasing by 250% since January 2021 mean that any cheap money saving product and ideas are vital at a time like this. At the time of writing the UK has seen a 6.6% rise in the CPIH rate in the last 12 months, meaning that the cost of living and housing market have shot up rapidly. The normal year on year fluctuation of this would be at most 1.6%, 0.3 – 2.6% in Jan 2016-17, (Office For National Statistics., 2022). The replacement and installation cost for new household heating systems is also very high varying from £110 for cheap manual thermostats to £400+ for ‘smart’ thermostat heating appliances.

‘Smart’ heating system are said to improve household heating efficiency by up to 12% (Blank., 2022). Programmable heating systems are also beneficial, however they do produce lower returns as they cannot be controlled remotely using a smartphone. These systems therefore rely on user planning and knowledge of their routine, for example, knowing what time they will arrive home from work so the boiler can preheat the house, however with a smart device if the user is later or earlier they can remoting change the program to suit them.

 

 

System Design – Concepts

Concept One –

For this concept I have decided to try and utilize heat that is already within the house to try and reduce energy wastage. It does this through sensors located throughout the house on windows and doors in tandem with temperature gauges in each room, these all work together alongside predetermined ideal room temperatures. The idea is to alert the homeowner when a room rapidly loses or gains heat due to a window or door left open or closed. It is indirect to the heating system however I think allowing them to communicate could result in the most effective product.

 

Concept Two –

Similar to the first concept my initial plan is to run this indirect to the heating system but provide a high intel monitoring system of air quality and temperatures.  The plan would be again to instal sensors in each desired room to monitor each room for; humidity, carbon dioxide, temperature, carbon monoxide, oxygen and pollon. As requested in the focus group the concept will be run on an app for ease of use and be presented something like what you see in the figure below. For both this concept and concept one the main challenge seems to be power, as using batteries is harmful for the environment and using a plug would be restrictive and not pleasing on the eye. To negate this I will look into wireless charging or rechargeable batteries, however the latter is prone to degradation over the years so it is important to take this into consideration.

 

Concept Three –

After looking on the internet for new thermostats I came to realise if you wanted to replace your outdated manual thermostat to one with a timer and more smart technology it can cost anywhere between £110 – £400. As many families could not afford this, I have decided to design a programmable adapter that would sit on the old manual wheel style thermostat and turn it up or down at specific times of the day/night. Incorporation of smartphone connectivity would shift the product from ‘programmable’ to ‘smart’ and create a better money saving device, however my paramount aim is to create a cheaper alternative device and I will not compromise on this. One potential limitation that I will need to conquer with this concept is ensuring that I can make it universally applicable for almost all manual thermostats.

 

Concept – Decision Matrix

For this decision matrix I weighed each need for the concepts out of 5, with 5 being absolutely critical and 1 being not needed. I then ranked the concepts ability to carry out the need by ranking it 1-3 with 3 fulfilling the need completely and 1 not covering it at all, at this stage of development.

The results of this matrix show that concept 3 is the best solution to my engineering problem as it scores best 3/5 of the tests and ranks much higher overall in the weight score section of the table.

Further Primary Research

To ensure I design a product desired by society I need to guarantee I design a product that satisfies the needs of the stakeholders (users). To make certain that I am designing something people want I have created a public anonymous questionnaire to gather valuable information that will enable me to further outline and cement my project needs and requirements. To view the questionnaire, click HERE.

Early results showed an overall need and desire for an alternative thermostat in the household heating market, as 41% of those who answered the questionnaire still own a manual thermostat, with 58% stating it too expensive or too much hassle to upgrade. When looking at the market for thermostats there is already a gap for cheap alternative programmable options, however, now I can quantitatively see a demand for such a product.

One potential drawback could be lack of information as almost half of those who answered said to have never even considered changing their thermostat. It is there imperative to get information out about the money that can be saved from using programmable devices, this will be most crucial during the marketing phase of the project. I can also see that the device needs to be sleek and visually inoffensive as 100% of those who answered the questionnaire wanted a thermostat to be inconspicuous. I will therefore use the adapter to hide the dated device it will be replacing as best I can, yet also ensuring it is neutral and unobstructive.

 

Needs and Requirements – Revisited

After choosing my concept to develop I want to revisit my needs and requirements for the project as my initial aim was vague but now I know where I want this project to end and what I want to get out it. It is important to identify the specific needs and requirements that I need to hit in order for this project to become a success.

The Needs

• Function as a programmable thermostat.
• Unit cost must be less than £50.
• Must be able to use it on at least five different manual thermostats.
• Offer bluetooth connectivity to control device.
• Inconspicuous design with no visible wires for power.

The Requirements

• Device must use a temperature controller that can be applied to work on at least five different manual thermostats.
• The device must have physical buttons for temperature/timings set up and to override, whilst also offering bluetooth with an app for set up/maintenance.
• The device must know the time to carry out specific tasks, predetermined by the user.
• The system needs to be simple to set up, suitable to be carried out by those without previous DIY experience in under 15 mins.
• The system must have memory to remember the presets from the user, ideally I would like to have three preset options that the user can create saving them time in the future.
• The device must be solar, battery or wirelessly powered to avoid an unsightly look and ensure the device is inconspicuous.

Deliverables/Milestones

• Concept Selection
• Full final design completion
• Final costings

 

Concept 3 – Development of Concept/Subsystems 

Temperature Control Axial System

For this product to succeed I must design it so the new wheel/stylis that controls the temperature can move across the x and y axis of the thermostat, this will greatly improve the universal applicability and therefore have a greater market coverage. In accordance to this I have looked into the mechanisms behind the axial movement of 3D printers. They are useful to look into as they work in the x,y and z axis so they use similar kinematics (see fig.8). There are a multitude of designs that will help to inspire progress for this project, however, I will be looking for a simplistic design focusing on function and cost efficiency. (see fig.9)

I will also need to ensure that the adapter can sit across almost all thermostats yet remain unobtrusive and subtle in a household setting. To achieve this I have researched into various popular manual thermostats finding their appropriate dimensions, from which I can specify my own necessary dimensions. I have found three popular manual thermostats, namely the; Honeywell Home T6360-1028 (84 x 84 x 37mm), ESI Controls ESRTM (117 x 100 x 49mm) and Warmup MSTAT (86 x 86 x 50mm) with varying dimensions. Knowing this, the inner edge of the device must be at least 87 x 87mm and due to a great disparity in unit depth across manual thermostats. I will aim to produce a magnetic stylus/control arm that will work within a depth range of 20mm to 50mm. This can be achieved through an adjustable stylus or through kinematics that work in the x,y and z axis, further research and development will need to be done to find the best option.

Control Arm

For the control arm, I will be using a telescopic design similar to that of an extendable pointer (see fig.10.). It will work through use of a magnetic tip and partnering magnetic strip that will enable the arm to rotate the wheel. I believe this approach to be the most effective as the magnet will not wear out and the force it would take to not slip on the dial without a magnet would be great. Enabling this to extend will mean that the kinematic system will only need to operate in a 2D plane, lowering product costs.

 

Power Supply

For this device to operate successfully it must have a constant power supply as any failure could lead to the device being out of sync and behind schedule. To achieve this it could be, solar powered, battery powered or use wireless charging, however the latter may cost too much to implement. I also want to try to stay away from batteries due to high relative maintenance costs, unless I can ensure that they will only need to be replaced every 6 months or so.

I will also look into taking the power direct from the old thermostat, however I want this product to be set up easily and this may contradict that. To find a solution for this problem I will need to calculate the power output of the device and it’s necessary power supply.

Wall Fastening

Again the device needs to be easy and quick to set up with even the least adept still able to install it, within this need the securing of the device onto a wall is important as if there is a need for a drill already many people would shy away from attempting it themselves. To combat this I want to introduce choice into the installation of this device with the option to use adhesive screw technology.

The German based company, ‘nie wieder bohren’, or ‘never drill again’ have developed drilless screw technology that utilizes adhesion to create strong securings suitable for both indoor and outdoor use. One drawback to this technology, although claiming a hold strength of 10kg per screw, a family with young children may find that the children pull on it and rip it off the wall, due to its less permanent nature. This could also lead to a potential plus side however, with the product not damaging the physical structure of the wall it could be suitable for those renting or moving house regularly.

 

Microbit

In order to allow all of the aforementioned subsystems to talk to one another I will have to use a Microbit. It must be able to record and remember information with the standard 256kB flash drive too small the storage hardware must be upgraded. It must also be coded to identify hours and minutes so that when the device is set up by the user it can keep track of time.

It must remember locations and the device works through the cycle of changing between two positions the Microbit must be able to accurately return to both locations. It should also be able to automatically deploy the stylus and using pressure sensors or perhaps just a timer, to find the partnering magnet on the old thermostat.

Design for Manufacture and Assembly – (DFMA)

Before progressing with the project it is important to explore the DFMA approach, as up to 85% of all future product costs come after the design phase (Division, 2019) it is essential to design the most cost effective and thorough product possible. It is common place to apply the DFMA approach that works through the prioritising of various standards in an attempt to reduce production costs and lead time to get the product into market. It is also used as a tool to study competitors products and also as a cost prediction tool for a guide in the negotiation with suppliers.

It practices a closer relationship between the designers and production personal to increase communication and more efficiently highlight potential drawbacks of design when going into production. This closer relationship allows for an increased understanding from the designers in the strengths and weaknesses of the production team, which can then more easily highlight potential issues.

The DFMA is split into two phases, first comes Design for Assembly which takes place after concept design. It normally aids in the simplification of the products overall design, often accompanying changes such as; the number of parts, use of standard parts, ease of assembly and multi-functional parts.

The second phase, Design for Machining focuses more on the production of the specific parts. It takes place after the final design but tries to simplify the manufacturing process and costs of the design through; avoidance of tight tolerances, avoidance of secondary operations and use capabilities of each process. The later ensuring the maximization each production technique in the hope of reducing steps in the production cycle.

Concept 3 – Material Selection

The material selection process of a project can make or break the product as it is vital that the selected materials enable the product to carry out its purpose as best it can for the user. However, it must also satisfy the needs and requirements of the project from material cost to manufacturing complexity. For this project my most crucial requirement that the success of this project hinges on is price, as I want to undercut the market to create a new sub-genre within the household heating market. I want this product to offer an alternative to the expensive and often unaffordable options that low income families/landlords cannot afford. Looking at figure 7 you can see the process for material selection.

 

I want to ensure that the unit cost and product price stays as low as possible, but would also like to ensure that the product can be made from recycled or recyclable materials wherever possible.

 

 

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