Republic of the Philippines
TECHNOLOGICAL UNIVERSITY OF THE PHILIPPINES
Western Bicutan, Km. 14 East Service Road, SS Highway, Taguig City
TUP – Taguig: Center of Excellence for Technology and Engineering Education
BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING
BASIC COMPUTER PROGRAMMING
ARDUINO-BASED
COOLING SYSTEM IN A
ROOM
Prepared by:
Victor Janette R. Red
Jannesa M. Lacanlale
BE-1A
Submitted to:
Prof. Rico Santos/Prof. Nestor Valdez
(Professor)
I.
Introduction
We all know that security is a need for every person and most of us have important things to secure like
documents and such, so we decided to come up with an Arduino-based electronic safe that can be opened
by typing the password (4 number) and scanning your fingerprint and RFID. We installed the safe a 20x4
LCD screen to view the settings you’re inputting to the system. We also programmed it to have an
interchangeable password. The project is used with an Arduino Mega as our microcontroller.
II.
Objectives
1. To be able to have a secure safe that’s electronically controlled.
2. To be able to produce a safe that can change the password thru the use of EEPROM.
3. To be able to produce a safe that has a default password in case the user forgot the current
password.
4. To be able to produce a safe that can be opened only by typing a password and;
5. Scanning your fingerprint or main RFID.
III.
Materials Used
Input:

4x4 Matrix Membrane Keypad
This 4×4 Matrix Membrane Keypad provides an easy interface for embedded systems such as an
Arduino. The 4×4 keypad has a total of 16 buttons in Matrix form, and it’s made of a thin, flexible
membrane material with an adhesive backing (just remove the paper) so you can attach it to nearly
anything.


Dimensions: 69mm x 76 mm

Cable Length: 85mm (include connector)

Weight: 8g

Operation Temperature: -20 to +40 °C
Fingerprint Sensor
This Fingerprint Sensor is user-friendly: you can control the module with embedded MCU, MCU with
serial port, MSP430, 51, AVR, PIC, STM32, ARM and FPGA, Arduino, pcDuino controllers etc. This module
is controlled by serial port control, you can also use serial port of a computer to control it.
This module includes hardware and software of optical fingerprint sensor, high-speed DSP processor,
high-performance fingerprint matching algorithm, large capacity FLASH chips etc.The fingerprint module
has stable performance, complete function of fingerprint collection, fingerprint registration, fingerprint
comparison, fingerprint search etc.

Supply voltage: DC3.6-6.0V

Operating current: 120mA max

Peak current: 150mA max

Fingerprint imaging time: <1.0 seconds


Window area: 14mm x 18mm

Signature profile: 256bytes

Template profile: 512bytes

Storage capacity: 162 templates

FAR: <0.001% (Security level 3)

FRR: <1.0% (Security level 3)

Safety ratings (1-5 low to high safety)

Search time: <1.0s

Interface: TTL Serial

Baud rate: 9600*Nbps(N=1~12, Default 6, that is 57600bps)

Work temperature: -20℃~+50℃

Work humidity: 40%RH~85%RH No condensing

Storage temperature/humidity: -40℃~+85℃; <85%RH

Dimension: 55mm x 21mm x 21.5mm

Weight: 20g
MFRC522 RFID Sensor
The MFRC522 is a highly integrated reader/writer IC for contactless communication at 13.56 MHz.

Operating frequency: 13.56MHz

Supply Voltage: 3.3V

Current: 13-26mA

Read Range: Approx 3cm with supplied card and fob

SPI Interface

Max Data Transfer Rate: 10Mbit / s

Dimensions: 60mm × 39mm
Output:

LCD 20 x 4

Text Color: White

Back light: Blue LED Backlight

Dimensions: 98mm x 60mm x 14mm

Buzzer

Relay

250VAC 10A, 28VDC 10A

Indicator LEDs

5V control voltage

Module size: 55mm x 16mm
Components:

12V Solenoid Lock
12V Solenoid lock are basically electromagnets: they are made of a big coil of copper wire with an
armature (a slug of metal) in the middle. When the coil is energized, the slug is pulled into the center of
the coil. This makes the solenoid able to pull from one end.
This solenoid lock in particular is nice and strong, and has a slug with a slanted cut and a good mounting
bracket. It’s basically an electronic lock, designed for a basic cabinet or safe or door. Normally the lock is
active so you can’t open the door because the solenoid slug is in the way. It does not use any power in
this state. When 9-12VDC is applied, the slug pulls in so it doesn’t stick out anymore and the door can be
opened.
The solenoid lock come with the slanted slug as shown above, but you can open it with the two Phillipshead screws and turn it around so its rotated 90, 180 or 270 degrees so that it matches the door you
want to use it with.

Arduino Mega
The Arduino Mega is a microcontroller board based on the ATmega2560. It has 54 digital input/output
pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16
MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains
everything needed to support the microcontroller; simply connect it to a computer with a USB cable or
power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields
designed for the Arduino Duemilanove or Diecimila.
The Mega 2560 R3 also adds SDA and SCL pins next to the AREF. In addition, there are two new pins
placed near the RESET pin. One is the IOREF that allow the shields to adapt to the voltage provided from
the board. The other is a not connected and is reserved for future purposes. The Mega 2560 R3 works
with all existing shields but can adapt to new shields which use these additional pins.

ATmega2560 microcontroller

Input voltage – 7-12V

54 Digital I/O Pins (14 PWM outputs)

16 Analog Inputs

256k Flash Memory

16Mhz Clock Speed
Connecting Wires
12V with 1A Power supply
IV.
Theories and Principles
Ohm’s Law
Ohm's Law deals with the relationship between voltage and current in an ideal conductor. This
relationship states that: The potential difference (voltage) across an ideal conductor is proportional to the
current through it. The constant of proportionality is called the "resistance", R. Ohm's Law is given by: V
= I R, where V is the potential difference between two points which include a resistance R. I is the current
flowing through the resistance. For biological work, it is often preferable to use the conductance, g = 1/R;
In this form Ohm's Law is: I = g
Faraday's law of induction
Faraday’s Law is a basic law of electromagnetism predicting how a magnetic field will interact with
an electric circuit to produce an electromotive force (EMF)—a phenomenon called electromagnetic
induction. It is the fundamental operating principle of transformers, inductors, and many types
of electrical motors, generators and solenoids.
Frequency
is the number of occurrences of a repeating event per unit of time. It is also referred to
as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency.
The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the
frequency.
Fingerprint Sensor
Used to scan for the user’s fingerprint in order to continue the function of the desired setting.
RFID Sensor (MFRC522)
Used to scan for the user’s RFID in order to open the electronic safe.
Buzzer
To indicate the buttons that is pressed, and if the input is correct or incorrect.
Keypad (4x4)
Used as the main input device that will distinguish what setting the user has to press in order to
open, change password or set the password to default.
LCD Screen (16x2)
Used to view the inputs that is pressed on the keypad.
Relay
Used for the solenoid to have a switch when you set it on or off.
Fan
Used as the main lock for the project.
LED Light
Used as an indicator.
V.
Methodologies
The operation of the E-safe requires the hardware and software designs.
For Hardware:
We have gathered the materials needed and make sure each part was verified to be working
correctly. Then, the door of the E-safe was mounted with all the parts and was assembled. We checked
for the appropriate wiring of the parts in order for the components to operate as they needed.
Then, we created a circuit that will connect the solenoid lock to the main power supply as well as
the Arduino Mega. The relay module will control the passage of current that will pass thru the solenoid in
order to operate.
For Software:
The program was designed and coded using Arduino IDE to test the components and modules.
Many libraries were used in this program in order for the modules to operate such as: MFRC522 RFID
Scanner, Fingerprint Scanner, 20 x 4 LCD, and 4 x 4 Matrix Membrane Keypad. It also includes a library
that allows the Arduino to save a certain input which is the password.
VI.
Data and Results
VII.
Circuit Diagram
Block Diagram
Schematic Diagram
VIII.
Data and Result
IX.
Observation
We experienced a problem in our power supply as the main supply produce only 1 ampere. The
Solenoid Lock requires 500mA. As soon as the Solenoid Lock operates the supply current was cut-off from
some of the modules that is powered by the Arduino, even if the Solenoid Lock powers down the supply
current does not flow throughout some of the components and modules.
We come up with a solution to automatically reset the Arduino every time the Solenoid Lock powers
down through coding.
After the current was cut-off from the Solenoid Lock 1A of currents is now free of use and the Arduino
and its connected components can use it after the Arduino resets itself.
X.
Conclusions & Recommendations
After designing, assembling, and merging all of the components, and testing the circuit, we have come
to the result that our Arduino-based electronic safe is working in a satisfactory results. This device was
also simple in design and reliable in operation. The inputs are successfully programmed using C
Language and their desired values displayed on LCD 16x2 on the outside of this project. The safe also
includes a feature to reset the password to the default password which is “0811”.
We recommend, that the project can be used in a bigger door scale given that the main
microcontroller is secured. We recommend that the safe be installed with a emergency power supply
back-up as the safe will be stuck in the locked position.
XI.
Prices