CP5070-2021-2B02-Group5-Cui Han: Project Development

Welcome to my last blog for this semester👌

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1. Our team chemical device: Breath Analyzer

The Breath Analyzer is able to detect alcohol in the driver's breathe and to sober the driver with the loud buzzer noise and cold splashing water. We aimed to reduce the number of drink and drive incidents with our chemical device.

2. Team planning, allocation, and execution

Team planning:

We first came out with the materials we needed for our chemical device.

BOM

Then we decided on how should we spread out the tasks so that we don't need to rush everything at the last minute.

link:

Initial Gantt chart template (click)

Finalized Gantt Chart Template (click)

We also listed the potential risk we might encounter during the building of prototype by using the risk assessment.

Example of risk assessment

Lastly, we came out with our first draft prototype drawing:

Draft Prototype

At first, we wanted to use the spray bottle to splash the water, however, we neglected the force of the motor is not strong enough. Moreover, we wanted to have a cushion layer as the drunk person might hold the device tightly unconsciously. The final prototype solved all the problems and it will be shown below.

Role allocation:

CEO(Chief Executive Oficer)- Kalyani

CSO(Chief Safety Officer)- Madelaine

CFO(Chief Financial Officer)- Jolyn

COO(Chief Operating Officer)- Cui Han (me)

Allocated Tasks:

Things need to prepare:

1. Body to contain all the components(Change from 3D print to laser cut to save time).

2. Spray bottle(3D Print).

3. Arduino code for MQ-3 sensor, led, buzzer, and spraying water.

4. Assemble the final chemical device.

Execution Plan:

TASK	ALLOCATION	DURATION
3D printed bottle	MADELAINE	2 hrs
Laser cutting body	JOLYN	2 hrs
Arduino program alcohol sensor,alarm and LED	CUI HAN	1 DAY
Integration of all parts and electronics	KALYANI	1 hr

3. Design and Build Process

Design and build of 3D printed bottle (done by Madelaine) click maddie

Water tank

Design and build of the body (done by Jolyn) click jol

Design and build of code and Arduino board (done by Cui Han)

1. Connect the MQ-3 sensor to the arduino board and test it with an alcohol swap.

MQ-3 sensor
Arduino board
GND
GND
VCC
5V
A0
A0

MQ-3 sensor connection

(Gas sensor is used since MQ-3 cannot be found in tinkercad)

Tinkercad

Code used to warm up the sensor:

Warming up of sensor

Initially we set the delay as 3000ms, but the sensor was not able to work well. After some research, we decided to extend the delay to 20000ms so there's enough time for the sensor to warm up properly.

2. I wanted to add in the LED to show the difference when alcohol is detected and when alcohol is absent. So I used the output signal from sensor as the input signal for the LED.

MQ-3 sensor
Arduino board
LED
(+resistor)
GND
GND
Short side
VCC
5V
Long side
A0
A0
pin13

with LED

Code added in:

int LED = 13 ;

void setup(){

pinMode(13, output);

pinMode(AlCOHOL_sensor, input);}

void loop(){

if (ALCOHOL_detected == 1)

{

Serial.println("ALCOHOL > 500");

digitalWrite(LED, HIGH); }

else

{

Serial.println("No ALCOHOL detected");

digitalWrite(LED, LOW); }

NO Alcohol sensed

Alcohol detected

Lastly, I added in the buzzer so it can produce a loud sound to sober the driver. Initially, we wanted to use a speaker, after some discussions we felt that the buzzer is good enough and it can help to reduce the cost.

MQ-3 sensor
Arduino board
LED
(+resistor)
Buzzer
GND
GND
Short side
-
VCC
5V
Long side
-
A0
A0
Pin13
pin8

Full code:

Video:

When alcohol is detected, the buzzer will ring with a jumping tone, when alcohol is absent, the tone becomes flat.

Integration of all parts and electronics(done by Kalyani) click kaya

Finalized drawing of our chemical device:

4. Problems and solutions

Key problems	Solution
The pump we were given did not have a connection that would allow us to connect it to the arduino, so we could not program it.	We operate the water system using a switch.
	We operate the water system using a switch.
We wanted to use spray bottle for our water, but could not program it so that it sprays when the alcohol is detected.	We 3D printed a hollow cylinder with a hole on the sides so the water shoots out.
We wanted to 3D print our body, but it took a lot of time.	We laser cut our body , it was easier and more efficient.

Limitations	Eliminate/ limit
Arduino boards and maker uno were given by the school, this led to our product to not be as compact as we wanted it to be.	Self-source for smaller arduino boards and maker uno.
Pump provided by the school was not able to connect to arduino .	We can source for pumps that have the ability to be connected to the arduino uno and it should not be too fragile.
The beep sound will not stop unless there is certainly no alcohol in the surrounding atmosphere .	Eliminate the sound system. Program it even further so that the sound can be eliminated after the alcohol level has lowered to a certain level.