Project Development

1. Our team Chemical Device

The use of a CO Detection and Ventilation System is an important device which can potentially save one’s life. The CO device can detect carbon monoxide in the atmosphere which is dangerous when inhaled.

 

Problem

CO will bind to haemoglobin found in red blood cell. This decreases the amount of oxygen which haemoglobin can be binded to, thus humans will face difficulty breathing when breathed in too much CO. When CO is bind with haemoglobin, this reaction is non-reversible. Therefore, when breathe in too much CO, one may lose consciousness and die due to lack of oxygen.

CO can be produced easily, even at homes. Some common sources which produce CO are clothes dryer, water heaters, boilers, fireplace, gas stoves, ovens, motor vehicles and tobacco smoke. Furthermore, since CO has no odour, colour or taste it cannot be detected by our naked eye or by our senses. This means that dangerous concentrations of the gas can build up indoors and humans have no way to detect the problem until they become ill. When people become sick, the symptoms are similar to flu, which can cause victims to ignore the early signs of CO poisoning.

Without proper detection and ventilation, humans can easily die to CO poisoning. Thus, the CO system device is an essential and important device which can help save human life.

The CO system device helps to detect CO in the air using a gas detector. Using programming, when the concentration of CO reaches a dangerous level of 175PPM, the CO system will start ventilating CO out of the indoor environment using a fan. An alarm will also be sounded by the CO system device which will alert humans inside about the dangerous level of CO in the air. They can then also do their own measures such as covering their nose with a cloth, and to open up the doors and windows to quickly reduce the concentration of PPM in the room. This simple device can save human life.

 

How is the problem solved

The CO Detector and Ventilation System is controlled by an Arduino, and will be able to able to detect Carbon Monoxide (CO) in the atmosphere. If CO is present, and is above the set threshold value of 175PPM, the ventilation system, which consists of the motor controller and the motor with a 4 bladed fan, will start spinning to help remove CO in the enclosed area to an outdoor area.

When CO concentration in the atmosphere is below threshold value, a green LED will be lit up and serve as a visual representation for the people in the room so that they know the area is safe for them to be in.

However, when CO concentration in the atmosphere is above threshold value, a red LED will be lit up and serve as a visual representation for the people in the room so that they know the area is unsafe for them. There will also be a buzzer (audio alarm) sounding to alert everyone in the room in case the red LED cannot be seen due to external conditions such as harsh sunlight. People in the room will also be able to do the necessary actions such as opening the window to further decrease CO concentration and can also leave the room while the ventilation system is on, and helping to ventilate CO out of the room.

Design

The CO Detector will be housed in a small sliding lid box, while the Ventilation System is found outside of the box. The entire system can be attached onto the wall using a strong tape near a window so that effective ventilation can take place.

2. Team Planning, allocation, and execution

Members	Allocated Roles
Lau Jun Foong Wayne	CEO, in charge for the Design and CAD of the Chemical Device.
Rong Yiren	COO, in charge of Arduino UNO and Coding of the Chemical Device.
Wong Kea Tzer	CFO, in charge for 3D Printing and the Construction of the Chemical Device.

Bill of Materials (Final):

Project Title:		CO-Detector with Ventilating System
Team members:		Lau Jun Foong Wayne, Rong Yiren, Wong Kea Tzer
Created by:		Wong Kea Tzer
Date created:		2 December 2021
BILL OF MATERIALS (BOM)
No.	Description of item	Supplier (Include hyperlink to the item in website of seller)	quantity	quantity unit	unit price (SGD$)	Total Cost	Available at W319 Lab or FabLab? (Y/N)
1	MQ2 Smoke LPG CO Sensor Module	Lab	1	Pieces (pcs)	$2.68	$2.68	Y
2	Arduino Maker UNO Board	Lab	1	pcs	$27.54	$27.54	Y
3	DC Motor	Lab	1	pcs	-	-	Y
4	4-Bladed Fan	Lab	1	pcs	-	-	Y
5	Acrylic casing (3D-Print)	Lab	1	pcs	-	-	Y
6	Dupont Wires (Male to Male)	Lab	1	Set	-	-	Y
7	Dupoint Wires (Female to Male)	Lab	4	pcs	-	-	Y
8	Motor Controller	Lab	1	pcs	-	-
9	LEDs	Lab	2	pcs	-	-	Y
10	Breadboard	Lab	1	pcs	-	-	Y
11	Strong Double-Sided tape	Hardware store	1	row	$9.90	$9.90	N
Grand Total Cost:						SGD$40.12

 

Final Gantt Chart Link:

https://docs.google.com/spreadsheets/d/1DtHQUh9auJQDZVtcJJG4F3bv1n1ThPV7/edit?usp=sharing&ouid=107171668789834527235&rtpof=true&sd=true  

 

With the concept in mind, we now had to get into the details to make this CO Detector and Ventilation system come to fruition. The first thing that we had to do was make sure that the system worked as intended, which required us to programming and properly wire the Arduino and breadboard. Yiren, who was in charge of this portion, had modified sample code from the Arduino website so that he did not have to start from scratch. We then had to measure the dimensions of the completed Arduino setup so that we can create the housing for it in Fusion360. Wayne, was in charge of this portion. Once the 3D model with the correct dimensions was successfully created, the Fusion360, an .stl file had to be imported into CURA for 3D printing and the final product had to be assembled. Tzer was in charge of this portion.

3. Design and Build Process

Part 1. Design and Build of CAD(done by Wayne).

Link: https://cp5070-2021-2b01-group4-wayne.blogspot.com/p/project-development.html  

Part 2. Design and Build of Part B (done by Yiren)

In this part, I will document how we did our Arduino programming and wiring. Before we start writing our code, we planned out what is the logic of our CO device. As we originally had to do programming for the buzzer, CO detector, motor and LCD screen, we required a lot of time to complete our programming.

 

However, we had decided to change an LCD screen to just LEDs for visualisation. Although the LCD screen shows the concentration of CO in the air, we found it non-practical as the CO system may be placed high up where users cannot see the words of the small LCD screen, and the main point of the CO system is to alert people when the concentration of CO exceeds the threshold value. It would therefore be better for a quick visualisation to be implemented rather than needing to read the LCD screen. Thus, we had changed our LCD screen to a quick visual representation of just a green LED and a red LED.

We did not start from empty scripts as it will be very time-consuming. To ease our work, we search code from the Arduino library to help us get a kick start our programming. The example code with an explanation is below.

The website we used:REFER CODE

The wiring looks like this, with all the components are attached to the correct position. The LEDs buzzer is in working condition.

We then need to add the DC motor in. At first, we thought that we can just set the DC motor as an integer and control it the same as the LEDs and buzzer. However, when we try it, the DC motor is not working, Thus, we asked Mr Mark who is expected the Arduino. He told us that the DC motor cannot be controlled directly from the Arduino UNO. He then provided us a motor control to help us.

The motor controller is able to receive the output from the Arduino Uno and converted it to appropriate electricity to drive the motor.  We went to the website of the brand of the motor to obtain the code on how to program it.

You can download it from THIS

We then selected the parts we need in this code to add to our script as we only need to control 1 motor. So below is our final script of our CO ventilation system

The wiring is like this:

As the THINKERCAD does not have all the components, This is just stimulation of the wiring. the real picture is below 

Four wires go to the motor controller where two is connected to the voltage and ground and the other two are connected to pin5 and pin6 that we define in coding 

Connect the motor to the PIN A of the motor controller

Hence, this is our programming and wiring process. The below hero shot shows that it works well.  

Part 3. Design and Build of Part C (done by Tzer). 

Link: https://cp5070-2021-2b01-group4-tzer.blogspot.com/p/project-development.html 

4. Problems and solutions

Problem #1: Motor cannot be controlled

Solution: We consulted with Mr Mark who is very experienced with working with Arduino systems and he suggested that we use a motor controller as he had a spare one in the Makers Space. He was extremely helpful as he not only explained what was wrong, which was that the DC motor cannot be controlled using only the parts provided in the maker UNO kit as it would not allow for the DC motor to be turned off when the system is powered, but he also told us the necessary information on the new part that he gave to us which made implementing this new part into our system easier.

 

Problem #2: 3D-Printing takes too long

Solution: With the default settings in place, the printing time for the whole box was estimated to be around 12 hours. To solve this problem, we had tuned the settings for the print speed. For an Ender Creality 3D printer machine, the default speed was 50mm/s. The max speed is 200mm/s. Thus, we had increased the printer speed to three times the default value, 150mm/s. This reduces the time needed to print the whole box to around 8 hours.

 

Problem #3: DC Motor wire is loose

Solution: Since we only had 1 DC motor remaining. after long usage of the DC motor, one of the wires became loose. Our DC motor can now only be spun when is tilted to a certain direction and angle. After asking around with other groups, we have managed to find and borrow a DC motor.

 

Problem #4: 3D printed Lid is unable to be slotted inside the hole of the 3D printed Box.

Solution: Using a sandpaper and gently sand the side of the lid and the clearance to make the gap larger, the lid can be slotted into the hole of the 3D printed box.

HERO Shots!!!!

Assemble Process

Demonstration

5. Project Design Files as downloadable files

If you want to find the stl. file, coding of our design, you can download from this link: HERE