Project Development

In this blog, I will be documenting the project development for this module.

1. Our Team Chemical Device

The objective of our product is to prevent drunk driving accidents by preventing drunk people from driving. With the help of our chemical device, this will greatly reduce the number of car accidents that is related to alcohol.

Cars are common in the 21^st century, as the number of vehicles increases, accidents related to cars also increases.  A lot of these accidents occurred due to irresponsible driving behaviour, like drinking while driving, which is one of the biggest causes of car accidents.

Our device is a breathanalyzer that is installed onto the steering wheel. The device can detect alcohol from the driver’s breath and once a certain alcohol level is detected, our device will alert the driver that he is not suitable to drive through the use of LED lights, alarm, system that prevents driver from starting the vehicle and LCD screen that shows the Breath Alcohol Content (BAC) and that alcohol is detected. This is how the LCD works when the driver is in:

• Proper condition for driving: LCD shows “SAFE TO DRIVE”
• Drunk state: LCD shows “BAC = xxx mg/L” and “ALCOHOL DETECTED”

As for the alarm, it will turn on once driver is unsafe for driving. The alarm will be activated together with the red LED lights once the driver is not fit for driving. If he/she is not under alcohol influence, the LED light will be green, and alarm is not activated.

As for the system that prevents driver from starting the vehicle, when alcohol is detected before the driver starts the engine, this system will prevent driver from starting the engine. This prevents the chances of drunk driving as the driver is not allowed to drive when he is drunk.

By using this chemical device, it will solve issues of the people from drinking while driving. When the alcohol sensor detects alcohol from the driver, the car engine will stop hence prevent the driver from driving. As such, this will reduce the number of accidents on the road. This chemical device promotes road safety.

2. Team Planning, Allocation & Execution

These are my team members and their roles:

Here's the Finalized Bill of Materials (BOM):

Here's our finalized Gantt chart which is the team's plan for this project:

3. Design & Build Process

Part 1: Design and Building of Breathanalyzer (Done by Kit and Steward)

Kit was in-charge of drawing the designs for the breathanalyzer, this is the link to his blog:

https://cp5070-2021-2b01-group5-kittitat.blogspot.com/p/project-development.html

I am in-charge of designing the breathanalyzer frame on fusion360. I have key in the design parameters first, which will be used for the dimensions of the frame:

I started off with the sketch of the device, the line in the middle is to separate the front and back part for the 3D printing later on, so that it will not take too much time.

Next, I extruded the sketch and made it hollow on the inside to store the components. The photo shows a cross sectional view of the device.

Next is to use the split body tool to split the device into halve as mentioned earlier. This will allow us to print the parts separately, to save time.

The next portion is to add the hinge, so that it is easy to access the internal components to modify or switch them. I have done this for the individual 3D printing session earlier, so the steps to build the hinge on this device is quite similar. The link to the blog is here: https://cp5070-2021-2b01-group5-stewardsoh.blogspot.com/p/3d-printing.html

The next step is to use the split body tool to separate the front and back part of the device from the hinge below. The hinge will also be printed separately

The next step is to join the parts back and fillet the side edges of the device with a radius of 3mm.

The next step is to cut out the holes for our components that will be exposed. The components are: 2 LED lights, alcohol sensor and the LCD screen. With the use of the 45° angled plane, it is used to cut out the two 5mm holes for the LED lights.

Since we will be printing the parts separately, my team and I have also decided to add a snap fit design to connect the parts together after printing. The video below shows the process of designing the snap fit.

After designing one snap fit, I duplicated it onto the other 3 corners.

I have also added a snap fit at the top of the device, so it can be closed and locked in place. After arranging the snap fit parts, I have combined them to their respective parts (hinge, front and back).

Lastly, for the wire to be connected to the Arduino from the outside, we made a hole so that the wire can pass through. 

By changing the colour, and importing the components, it will help us visualize how the components will fit in the final device. If there were any adjustments required, it can be adjusted at this point. This is done so to maximise the space within the device to make it compact.

After finalizing our idea, we went on to 3D print the parts shown in the video below.

 

Due to the long duration of printing, we decided to increase the print speed and adjusted other print settings to shorten the duration. However, the trade-off is that the print quality was really bad, so the snap fit that was designed earlier did not fit at all. So, we had to improvise, and we decided to use hot glue to join the parts together.

This was the final product for our 3D printing design.

Part 2: Design & Building of Steering Wheel (Done by Kit and Nander)

Here's the link to Kit's blog:

https://cp5070-2021-2b01-group5-kittitat.blogspot.com/p/project-development.html

Part 3: Arduino Programming (Done by Steward and Nander)

Here's the link to Nander's blog:

https://cp5070-2021-2b01-group5-nander.blogspot.com/p/project-development.html

Part 4: Integration of All Parts and Electronics (Done by everyone)

For the integration of our components, we first used Fusion360 to ensure that our printed breathanalyzer frame is well thought out in terms of dimensions. After using Fusion360 to position all the components inside the frame, we assured that the frame can fit the components well.

During the integration process, we used sticky tape to ensure that the breadboard and MAKER UNO is placed firmly on the back part of the frame. After that we connected the wire and placed the MQ-3 sensor and LCD to the corresponding holes that are located on the front part of the frame. The holes are designed specifically for them so that they can fit there perfectly. We also used paper tape to help us ensure that the wires were well connected for the LEDs, because the wires are quite loose and short so paper tape is used to join the wires firmly. After which, we closed the frame after integrating all the components. Continuous servo is not included in the frame because it is just a representation of the car engine. Here's a photo of our product:

These are the components for the breathanalyzer that were imported into fusion360:

 This is the final chemical product design on fusion360:

Here's a demonstration of the breathanalyzer:

4. Problems & Solutions

5. Project Design File as Downloadable Files

Here's the link to all the downloadable files (steering wheel, breathanalyzer and Arduino Codes):

https://drive.google.com/drive/folders/16y1UlO99ExiB388gULxJICAROKm0-nkl?usp=sharing

Reflection

For this project, we did a lot of things such as designing prototype using CAD Fusion360 and printing it out using 3D printer and laser cutting the steering wheel. Not only that, but we also used what we have learnt from Arduino Programming tutorials and applied it in this project. Basically, this project tests us on all the technical skills we have learnt from ICPD and CPDD. We would say it is not easy to build a breathanalyzer in a short semester because it was our first time building a smart device and we feel puzzled from time to time as things did not work out the way we wanted. 

Nonetheless, what we could do to tackle the challenges is to go back to the lecture notes, practices, and blogs where we have documented everything we have gone through. For example, during laser cutting, we forgot what the setting is for cutting and engraving so we referred to our blog and managed to do it smoothly. As for the Arduino programming, what we learnt in tutorial is not sufficient to meet our objective so what we did was to do a lot of research and find resources and videos that could potentially help us to make our breathanalyzer works. We tried the codes on our circuit and see if it works, if not we improvise the codes so that it meets the objective. We only managed to make our Arduino Programming work after the fourth time of trying it. What we learned from this experience is that it is important to have growth mindset and perseverance because we would not have come this far without that mindset. When met with challenges, instead of giving up, we always try again and encourage one another that it can work.

When doing this project, we always try to do it face to face with minimal online meeting as we find doing face to face more efficient. As we know that the school curriculum is very tight, we treasure the time where we met in school for CPDD and practical session as this is the only time where we can really make big progress with all the facilities available. For every class or practical session, we always set a goal to finish by the end of the day so that things are going according to our plan.

In conclusion, even though we learned a lot of technical skills, we also learned a lot of soft skills such as communication. Communication is key and, in our team, we respect and listen to one another opinion so that no one is left out. During the process, we also find out about the working style of each member, so we know the strength and weakness of one another. Thus, we always try to help with one another weaknesses. For example, I am better at programming, so he takes in charge of programming. Kit is better at designing and sketching so he did the drawings and Nander help out with researching and editing videos. We are confident that our skills will help us go through the final year capstone project. Overall, it was a fun and fruitful experience that I am glad we are part of.