Microcontroller Application Development Contest Report
Arduino Indoor Environment Monitor
 Group member
XU Dongqi
15111597D
YANG Xi
15111544D
ZHANG Lihuan 15111788D
 Introduction
Nowadays, people have more attention on the air quality of indoor environment
where they stay since it is highly related to their health. This indoor environment
monitor based on Arduino integrates a thermometer, a hydrometer and an air
quality monitor into one single system so that users can easily know the indoor
environment by using it. Instead of providing the exactly values of temperature,
humidity and PM2.5, this indoor environment monitor shows these information in
a better way. A tricolor LED will show different colors according to different
temperature and humidity. When the temperature is low, the LED will show blue
light. When the temperature is high, it will show red light. In addition to LED, an
old fashion but interesting way is used and that is a dial with a pointer. A servo is
used to implement this feature. Moreover, users can directly get the temperature,
humidity and air quality information on their mobile phones through e-mail. The
email is sent by the microcontroller board with built-in Ethernet and Wi-Fi
module. If the user want to read the data directly, a LCD is provided to display
the information. In the end, we have implemented most of the above functions but
we fail to implement the PM2.5 meter in the indoor environment monitor.
 Material of the Final product
1. Temperature & Humidity Sensor SHT10
The temperature sensor can transform the temperature information into voltages
so that it can be detected by the Arduino Yun. After analog to digital conversion,
the temperature information can be obtained. The humidity sensor can transform
the humidity information into voltages so that it can be detected by the Arduino
Yun. After analog to digital conversion, the humidity information can be
obtained.
2. Air Quality Sensor
The air quality sensor can detect the particle concentration in the indoor
environment and communicate with Arduino. Therefore, Arduino can obtain the
air quality information. However, we can only successfully implement this
function on the Arduino Uno but not Arduino Yun.
3. Servo
According to the temperature, humidity and air quality information obtained by
the sensors mentioned above, Arduino can control the servo (which controls the
pointer on the dial) to rotate a certain angle and point to specific location on the
dial. Therefore, users can obtain the temperature, humidity and air quality
information by reading the value on the dial.
4. Tricolor LED
The tricolor LED is controlled by Arduino so that it can display light of different
colors according to different temperature, humidity and air quality index. For
example, when the temperature is relatively low, the LED can show blue light
and when the temperature is relatively high, the LED can show red light.
5. Arduino Yun
Arduino Yun is a microcontroller board based on the ATmega32U4 and the
Atheros AR9331. The board has built-in Ethernet and Wi-Fi module, which can
communicate with mobile phones through the Internet. It can send the
temperature, humidity and air quality information to an App so that users can
read these information on their mobile phones. In addition, Arduino Yun is able
to send the temperature, humidity and air quality information by email. It can be
set as a routine to send the information regularly every day.
6. Liquid Crystal Display
The liquid crystal display is an optional approach to display the data of the
temperature, humidity and air quality information as well as the date and time.
 Cost
 Arduino Yun
HK$600
 Liquid Crystal Display
HK$20
 Temperature & Humidity sensor
HK$100
 Air quality sensor
HK$250
 Servo
HK$20
 Tricolor LED
HK$50
 Other(hardboard, resistor…)
HK$50
-------------------------------------------------------------------------------------- Total
HK$1090
 Product Demonstration
After switching off the Arduino Indoor Environment Monitor, the LCD will
show “hello world”. It will take some time to initialize it.
As it shown on the LCD, the temperature in the room is 21 degree Celsius. We
can also read it in the dial.
The Arduino indoor environment monitor can also send the information to a
mobile phone.
After implementing all functions, we designed a case for the Arduino indoor
environment detector with the use of DesignSpark Mechanical, a simple but
powerful software. Although we did not print out our design, we gained some
experience in 3D printing design. We felt DesignSpark Mechanical is so simple
to use so that we only spent few hours to make it.
 Review
Although we made a good proposal before the competition, we fail to implement
all functions in the proposal due to the following two reasons:
1. Our time management is poor: we pay our attention on the robot car and the
time we spent in implementing this product is not enough.
2. When we met some difficulties during the product implementation, rather
than asking teachers for help, we chose to implement the product by ourselves.
Eventually, we gave up reading the PM2.5 information on the Arduino Yun.