Revisi Bahasa Inggris Yang Benar

8/10/2019 Revisi Bahasa Inggris Yang Benar

1/5

1

Abstract-Temperature is a physical variable that is essential

in everyday because temperature change leads to changes in

some physical variables so that this condition requires a

control system. In this study design has been made automatic

temperature control system based on microcontroller which

aims to keep the temperature in a room is at a certain value as

desired. Temperature sensing using LM35 temperature sensor

and is managed by a microcontroller ATMega8535 to be

displayed on the LCD 2x16 characters and made the process

of controlling the room temperature setpoint by a

predetermined value. The process of temperature control was

performed on a lamp as a heater and two fans as cooler. The

control system is built by using four temperature sensors

placed on the sides of the room so that the control can be

conducted with referencing to the measurement of the four

sensors. The test results and data analysis show that the

control system has been built to run well and be able to

maintain the temperature of the system to remain on the

setpointvalue.

Keyword-Temperature control, LM35 temperature sensor,

microcontroller ATMega8535.

I.

INTRODUCTION

The temperature of a room that is not isolated to the

environment has a tendency to undergo temperature changes

when the temperature changes. This will continue to happen

until the ambient temperature and the room temperature reach

the equilibrium. In system like this, need to control the

temperature so the temperature of the room can be set and

maintained at a certain value to our liking even though the

ambient temperature changes.

Temperature control system is needed in the testing

laboratory and the industrial world. This is because some

physical quantities can change with changes in temperature,

such as the volume of a liquid, a solid length, gas pressure at

constant volume, the electrical resistance of a conductor andthe color of an object [1]. While in industry control system it

is needed among other things to ensure that a product is not

defective, ensuring that the engine produces the same

temperature in the production process, creating a suitable

environment for a product that can thrive and others.

The temperature control system is often not optimal to keep

a uniform temperature distribution. This requires a method of

controlling a well-integrated system that creates an

environment that has a uniform temperature in every part of

the room were controlled.

Performing a temperature sensing requires a sensor. The

temperature sensor is a device that functions for temperature

sensing and converts electrical signals into a form such as

custody, strong currents and voltages through several stages of

conversion. In its application, the choice of temperature

sensors depends on several things, such as the required

temperature range, linearity, accuracy, price, property, and

compatibility with electronic circuit design support [2].

LM35 temperature sensor is a temperature sensing

providing an output voltage proportional to the measured

temperature, in degrees Celsius. IC LM35 has a high level of

linearity with a sensitivity of 10mV/ 0C so that the sensor can

do the sensing temperature for every 1 0 C change in

temperature resulting changes in the voltage of 10mV. IC

LM35 has low self-heating of less than 0.5 0C, so the level of

errors in temperature readings will be low. Another advantage

of the LM35 is a small current consumption of less than 60A

[3].

Work arrangements in the sensing and temperature control

are set by a microcontroller. Microcomputer is a computer

system that all or part of its elements packaged in a single IC

chip, called single chip microcomputer [4]. Microcontroller

consists of Central Processing Unit (CPU), memory, input /

output, bus, clock, and other connected and organized internal

devices [5]. Microcontroller is resulted from the developmentof semiconductor technology which results a chip with a very

fast computation capability in a small form factor and low

prices [6]. Microcontroller ATMega8535 is an 8-bit

microcontroller AVR microcontroller family that has been

equipped with 8 channels Analog to Digital Converter (ADC),

which serves to convert analog signals into digital signals [7].

Liquid Crystal Display (LCD) is a viewer that is absolutely

necessary as a source of primary information giver and the

most widely used because it looks interesting and low power

consumption. LCD is equipped with a chip that functions as

the HD44780 LCD controller that has a Character Generator

Read Only Memory (CGROM), Character Generator Random

Access Memory (CGRAM), and Display Data RandomAccess Memory (DDRAM) [8]. Controlling the lights and fan

mechanical equipment through the relay contacts working

principle is based on the nature of the electromagnetic voltage

regulated through the provision of a microcontroller that relay

becomes ON/OF.

Design Of Automatic Temperature Control

System Based Microcontroller ATMega8535InfiantoBoimau, Endarko

Department Of Physics, Faculty Of Mathematics And Natural Science

Jl. AriefRahman Hakim, Surabaya 60111E-mail: [email protected]


2/5

2

II.

METHOD

The control temperature system space built consists of five

parts, namely the LM35 sensor as sensing element,

ATMega8535 microcontroller as the central control system

settings, the LCD as a viewer to provide information, relay

driver circuit for controlling lights and fans, and power supply

circuit to provide a voltage source for the whole set as

necessary. Sensor LM35 will perceive the room temperature

and then the results are sent to the microcontrollerATMega8535 to be managed as useful information. Before the

signals from the sensors managed by the microcontroller it

must be converted first to digital signals because the signal

shape of the sensor is in an analog signal form. The

conversion process will be carried out by the internal ADC

ATMega8535 owned by the microcontroller 10-bit wide data.

Signal conversion result is then processed by the

microcontroller to obtain the value of the room temperature

after sensing displayed on the LCD to provide information to

the user. The value of sensing sensor result will also be used

as input to evaluate the room temperature to stay at setpoint

value by controlling the fans and lights automatically through

relay driver. The design of the room temperature controlsystem built in full can be seen in Figure 1.

Figure 1.Block diagram of system design room temperature

The hardware techniques are designed separately within a

few blocks of the circuit includes power supply circuitregulated +5 VDC, VDV +9, and +12 VDC, sensor LM35,

2x16 character LCD, ATMega8535 minimum system

microcontroller and relay driver circuit. Each block is tested

and then proceed with the testing of the overall system. Circuit

in each block can be seen in Figure 2. Besides, the software

design is also divided into several separate procedures so

much easier to do testing and checking the error of the

program. Temperature control program flow diagram is shown

in Figure 3.

The measurement techniques conducted on the direct

measurement of the variables to be measured are temperature

and voltage measurements on each block of the circuit and

indirect measurement including the sensitivity and linearity ofthe sensor. Data analysis technique used consists of a

graphical method and error analysis. Plot data is done using

the Microsoft Excel program. With the graphical method, the

relationship between two variables obtained from the

measurements, the shape equation approach, and the slope of

the initial value will be determined. Meanwhile, by using the

error analysis, it will determine percentage of deviation

between the results of measurements and calculations.

Figure 2.Each block circuit temperature control system

Start

End

Initialization I/O ports,

variable and constanta

Take temperature of the

LM35

LM35 value conversion to

digital signals

Calculate the temperature of

the LM35

Show the value of the

temperature on the LDC

Whether the

temperature sensor

1>=30C?

Lamp OFF

Fan ON

Whether the

temperature sensor

2>=30C?

Whether the

temperature sensor

3>=30C?

Whether the

temperature sensor

4>=30C?

Whether the

temperature sensor

1


3/5

3

III.

RESULTS AND DISCUSSION

The system for run optimally will require testing of

individual circuit blocks and test consistency of the whole

system. Testing of the system includes hardware testing and

system performance testing designed by the function 4.87 V

8.95 V and 11.89 V are obtained in testing of the power

supply, at the output of each ofLM7805, LM7809 and

LM7812 regulator series of power supplies which are built.

Tests on the LCD and the microcontroller are done by certainposts on the LCD display. Meanwhile, testing the relay driver

built is done with the ON/OFF relay through regulation by the

microcontroller. The results of system design built can be seen

in Figure 4.

Figure 4. The control system design

Tests on several blocks of the system and the results of

performance testing of prototype designs include:

1.LM35 temperature sensor calibration

LM35 Sensor tests carried out to obtain which sensor that

has the same measurements with a standard thermometer. In

this study, the four sensors used do not have the same

detection compare with analog thermometer (mercury

thermometer) so we need calibration. Testing is done by

placing the four sensors and analog thermometer at the same

point for sensing the temperature at that point while the

temperature of the place is changed. Sensor calibration

performed on the water has a temperature ranging from 15 C

to 60 C. The results of the four sensor calibration are shown

in Figure 5.

Figure 5.Sensor calibration graph

Each calibration result from the four sensors has a linear

regression of 0.999 and the linear equations obtained are usedas a correction to calculate the temperature of LM3. From

linear equations of each sensor, it can be seen that the variable

y is the temperature measured by a thermometer analog

whereas x is the temperature measured by the sensor LM35.

Thus, we get four equation corrections to the LM35 sensor

readings.

2.

ADC testing

To determine the relationship between the ADC conversion

data to enter the ADC voltage can be determined by providing

a voltage across the potentiometer to the ADC input. Plot

ADC test results can be seen in Figure 6.

Figure 6.ADC test result charts

From Figure 6 above, it shows that the amount of voltage

conversion input factors to become digital data by ADC is

equal to 50.84 times with offsets of 1.125.3.

Testing control response

Responses to run the prototype in process control are a

benchmark for the performance and effectiveness of the

prototype in the process control. Tests on the response of the

control in response to changes in temperature to keep the room

temperature remains atsetpointvalue are shown in Figure 7.


4/5

4

Figure 7. Prototype response graph

Testing is done with a value of 30 C and the setpoint of

the graph can be seen that each sensor has a different

optimization response. This is due to poor air circulation in the

system so every corner of the room has no similar temperature

distribution. According to the four graphs above, an average

deviation from the setpointvalue of each sensor was obtained

at 0.533 C, 0.238 C, 0.266 C, and 0.616 C.

4.

Testing the entire systemTesting of the entire system is intended to determine the

performance of the prototype that was built in temperature

control chamber. Control is done by referring to the results of

the four sensing sensors placed on each side of the room so as

to create a temperature spread fairly evenly on each sides of

the room. The results of testing the control system can be seen

in Table 1.

Table 1.The results of testing the control system

The test results of the prototype show that, the temperature

in every side of the space are in the hold fixed setpoint based

on the determined value. In the table above, it can be observed

that when the temperature measured by the four sensors under

the setpointvalue, the light will be ON while the fan will be

OFF. Meanwhile, when the temperature measured by the four

sensors is above the setpointvalue, the light will go OFF and

the fan will go ON. In this condition, when one of the sensors

that perceive the temperature has a value below the setpoint

value light will be ON and the fan will be OFF, this conditionwill be maintained until the temperature of the four sensors

shows a value above the setpoint then the light will go OFF

and back ON the fan. This system will be maintained

continuously until there is another treatment of the user.

IV.

CONCLUSION

Based on the results of testing and data analysis, then some

conclusions are obtained as follows:

1)

Internal ADC ATMega8535 owned by the microcontroller

has good linearity to be used as a digital signal converter.

2)

LM35 temperature sensor can perceive the exact

temperature after calibration with an analog thermometer.

3)

The control system built has pretty good control response

with an average error of each sensor owned by 0.533 C,

0.238 C, 0.266 C, and 0.616 C of the setpointvalue

(30).

4)

The control system built as a whole is able to work well in

controlling the room temperature.


5/5

5

REFERENCES

[1] Serway. R. A and Jewet. J. W, Physics for Scientist and

Engineers, Thomson Brooks/Cole, vol. 6, 2004.

[2] Lacanette. K, Temperature Sensor Handbook. National

Semoconduktor Corporation, 1997.

[3] Asrizal, Analisis Hubungan Besaran Fisika Pada Sistem

Kotrol Temperatur Dengan Sensor PTAT Tipe IC LM35

Berbasis Mikrokontroler AT89S51,Jurnal Eksata, vol.

1, 2010.[4] Wahyudin, D,Belajar Mudah Mikrokontroler AT89S52

Dengan Bahasa Basic Menggunakan BASCOM-8051.

Yogykarta: Andi Offset, 2007.

[5] Winoto, A,Mikrokontroler AVR ATMega8/32/16/8535

Dan Pemrogramannya Dengan Bahasa C Pada WinAVR.

Bandung: Informatika, 2008.

[6] Putra, A. E,Belajar Mikrokontroler AT89C51/52/55.

Yogyakarta: Gava Media, 2002.

[7] Bejo, A,Rahasia Kemdhan Bahas C Dalam

Mikrokontroler ATMega8535. Yogyakarta: Graha Ilmu,

2008.

[8] Heryanto, M. A and Andi, P. W,Program Bahasa C

Untuk Mikrokontroler ATMega8535. Yogyakarta: Andi,2008.

Documents

Revisi Bahasa Inggris Yang Benar