8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

Development of Temperature Control Monitoring System for Server Racks 1Bamigboye,

O. O.; 2Ehiagwina, F. O.; 3Onawola, H. J., 4Seluwa, E. O.

1, 2, 4

Department of Electrical/Electronics Engineering Federal Polytechnic, Offa, Kwara State

3

Department of Computer Technology Engineering Federal Polytechnic, Offa, Kwara State

Abstract The aim of the paper was to automate and control temperature for a server room. The system is allowed entry of a desired room temperature within a prescribed range and to exhibit overshoot and steady-state temperature error of less than 1 degree displaying the value in real time. It can be applied in industries, auditoriums, green house buildings, server rooms and nuclear facilities. It is shown that the solution requires broad knowledge drawn from several engineering disciplines including electrical, mechanical, and control systems engineering. A temperature sensor has been used to measure the temperature of the server room using. The simulation of the system has been done on Proteus Professional Software v 8.3 and the graphs showing relationship between server room temperature and the digital value from the sensor to validate the accuracy of the system. Hardware implementation has been also done. The results of the research and Output waveforms have been investigated. Various design criteria, performance characteristics, comparison with different parameters Keywords: Controlling, microcontroller, monitoring, sensor, server, temperature.

1 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

1.0 Introduction Heating and ventilation systems play a vital role in providing a comfortable, practical and healthy environment in our workplaces and homes. The provision of adequate heating and ventilation is becoming increasingly important in industry, particularly in office buildings with high employee densities. This is not only a key issue in providing work conditions that ensure employee satisfaction and hence increased productivity. Subsequently, fire, health and safety regulations are provided. In tropical area such as Nigeria, temperature control is critical in a server room, hence, air ventilation systems are usually implemented for maintaining satisfactory comfort conditions by keeping the temperature of the server within a certain range. The energy consumption as well as indoor comfort aspects of ventilated systems is highly dependent on the design, performance and control of the system and equipment (Fulford, et al, 2014). To accurately control process temperature without

extensive

operator

involvement, a temperature control system relies upon a controller, which accepts a temperature sensor such as a thermocouple as input. It compares the actual temperature to the desired control temperature, or set point, and provides an output to a control element (Ismail, 2006). Temperature control will reduce the equipment damage for computer devices as a result of excessive temperature. Due to the process of sending and receiving data there must be a transmitter and receiver to complete the task. Besides that, an 8051 is used to store and process the data then command the LCD to display the data at the receiver. A presentation of related works and component description of the system is presented next. Kwakyea, (2007) reported the implementation of automated temperature tracking system in operation theaters, Intensive Critical Care Unit (ICCU), and Neonatal Intensive Care Unit 2 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

(NICU) in an hospital. Maintaining them manually is labor intensive and error detection process for maintenance. The paper provided custom software to simultaneously monitor room temperature in several locations throughout the hospital using iButton temperature sensors and Tiny Internet Interface (TINI) networked microcontrollers.

1.1

Speech Synthesized Temperature Sensor

Speech Synthesized Temperature Sensor is the device that informs the user via a verbal message of the current environmental temperature. The warning message can be programmed to execute repeatedly to really get the drivers attention. Also, the device could be used as an aid to the visually impaired. 1.2

X-10 Based Remote Temperature Monitoring System

X-10 based remote temperature monitoring system is made up of two separate components, the temperature sensing transmitter (TST) and the central receiver. Each time the receiver receives a new temperature reading the microcontroller page is updated to display the current temperature (Luo, 2010). 2.0

Materials and Method

The system, shown in figure 1 is divided into three main parts: the sensor circuit, the micro controlling unit, and the display circuit. The sensor circuit contains the IC temperature sensor. The analogue outputs from these sensors are analyzed and converted into digital signal which encompasses a microcontroller.

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8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

Figure 1: The Block diagram of temperature monitoring The microcontroller, 8051, is the heart of the system. It accepts inputs from a semiconductor type temperature sensor, LM35 which allows for the measurement of the current room temperature, and it is then displayed using LCD. All these input and outputs are accommodated by parallel ports on the microcontroller. Finally, a pulse-width modulation (PWM) output on the microcontroller is used to drive the server. 2.1

Design of the Power Supply

Five volts power supply with respect to ground is needed for the operation of the microcontroller. Figure 2 shows the schematic of the power supply used by the microcontroller. The power supply consists of a step down transformer which is used to convert 230 V, 50 Hz AC voltage to 12 V AC, 50 Hz. This 12 V AC voltage is given to the bridge rectifier, which converts it into 12 V dc. A voltage regulator 7805 is used to convert the 12 V dc into 5 V dc which is needed by the microcontroller. Capacitors are used for smoothening the output voltage. This five volts dc thus produced is given to the microcontroller for its operation

4 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

Figure 2: Power supply circuit

Figure 3: Temperature sensor description Source: Panagopoulos, 2015

2.2

The Sensor Circuit

The temperature sensor is LM35, shown in figure 3 has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. It also does not require any additional calibration or trimming in order to get typical accuracy. It draws only 60μA from its supply, it has very low self-heating, less than 0.1°C in still air. The LM35 is rated to operate over a 55°to+150°C temperature range, while the LM35C is rated for a -40°to+110°C range(-10° with improved accuracy).

5 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

XClk

Divided by 12

Divided by 32

Divided by X Baud Rate

UART

Figure 4: Baud rate block diagram

2.3

Baud Rate Calculation: Internal timer stages are as fallows

Divided by X box can be replaced with T1 timer so that by changing the value of timer we can obtain the required baud rate. Let the clocking rate of the X box, X clk = Baud Rate

=

11.0592 MHz

( X clk / 12 / 16 / 2 / X)

For attaining 9600 baud Rate, X can be calculated as =

11.0592 x 106 / 12 / 16 / 2 / 9600 =

3 So set the 2’s Complement of 3 in Timer 1 so that we can achieve 9600 baud rates. 6 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

Figure 5: Circuit Diagram for the Server Monitoring 3.0

Implementation of the Server Room Circuit

The construction started with mounting of the components on a paper-board (Breadboard). The paper board circuit arrangement was done stage by stage. The components for the temperature measurement stage, ramp generator comparator and ac power control components consisting of the opto-coupler and power triac were connected together with jumper wires. The temperature level control and power switch were put in place and eventually the power supply was connected finally to power the circuit. The analog to digital converter stage was also set up including the liquid crystal display to display the temperature value. The complete circuit was tested on paper 7 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

board. After the test and proper adjustments of component values, the components were transferred to Vero-board for permanent soldering. The soldering too was done stage by stage to ensure proper connection of parts, components and wiring. During the soldering work, the power supply stage was first of all soldered as it is needed to power subsequent stages. This was followed by the ramp generator, error amplifier or comparator, optocoupler and the power triac stages and the ADC stage. Each stage was tested at the end of the soldering in order to detect any problem on time before the circuit soldering is completed. The complete circuit was soldered eventually accordingly according to the circuit diagram.

3.0 Result and Discussion The testing was done stage by stage as each stage construction was completed. This approach is best as it enables one to quickly identify stages that are not working properly and those to be corrected. The power supply was connected first of all and tested to ensure proper supply voltages. The temperature sensor output was measured also followed by the ADC, and microcontroller. The test carried out was heating up of the sensor and observing the cooling of the server room. The test result recorded was that for the temperature readout value and the digital measurement from sensor. The result is as shown in Table 1. Table 1: Temperature Controller Test Result S/No Temperature readout oC measurement with sensor (Digital) 1 30 30 2 40 40 3 50 49 8 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

4 5 6 7 8

55 60 65 70 75

56 60 66 70 74

The test results shows that the controller has a direct control relationship as it is controlling the server as the temperature of the sensor was increasing until it got to its final speed level and vice-versa. This work also shows how the proportional band temperature controller works compared to on and off switching control. It is better suited to applications that require varying levels of control of the ac power to a load.

Figure 6: Digital voltage with temperature Measurement From figure 6, as the temperature of the server room is increasing, the digital voltage also increases. This cool the server room once the temperature reaches a particular threshold value, instead of the server room to be overheating; the control system will switch on the fan to cool it.

9 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

8TH INTERNATIONAL CONFERENCE OF THE SCHOOL OF ENGINEERING AND ENVIRONMENTAL, FEDERAL POLYTECHNIC, EDE, 18-20 JULY, 2016

Fig. 7: Developed server monitoring system The microcontroller was programme using assembly language. The developed hexadecimal file was hardwire inside the 8052 chips using a universal programmer. The circuit of figure 7 was designed on printed circuit board. All the components used were inserted into the appropriate place on the printed circuit board and the result was tested with different series of temperature to ensure the control system can adapt and control different temperature of the server room. 4.0

Conclusion and Recommendation

The paper work was a success as the aims and objectives enumerated earlier were achieved. The paper work which is about the design and construction of a temperature monitoring system for controlling the server room. The circuit consists of a temperature sensor that measures the temperature of the surroundings and a ramp generator for creating a pulse-width modulated waveform in conjunction with the comparator. The comparator compares the sensor voltage level with the ramp waveform to generate a waveform to control the firing of the power triac. The simulation of the system is working properly and the design is appropriate according to the modern needs and technology. 10 THEME: SCIENCE & TECHNOLOGY FOR ECONOMIC & SECURITY SUSTAINABILITY

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This design can be further extended in terms of area and power at layout and characteristic level by using Advanced VLSI applications. Moreover, parameters like humidity, light can monitored and controlled. In additional, a means of transmitting server condition data, wirelessly or via the internet can be included in the design. Reference Fulford., J, Gu., Y, & Welsh., M. (2014). "A portable, low power, wireless two-lead EKG system," Proceedings of the 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. Vol. 1(2), pp. 2141-2144. Ismail., B,

Taib.(2006) "Development of a Single Phase SPWM Microcontroller-Based

Inverter", Proceedings of the Annual International Conference of the PECon, November Vol. 3(4), pp. 437-440. Kwakyea., S. and Baeumner., A (2007). “An embedded system for portable electrochemical detection", Sens. Actuat. B, vol. 123(1), pp.336 -343. Luo., X, Zhao., M, and Xu., J. (2010). "A new hybrid elevator group control system scheduling strategy based on particle swarm simulated annealing optimization algorithm", Intelligent Control and Automation (WCICA), Vol. 9, pp. 5121-5124. Md., M, Islam., F & Md., R, Mitul., W, and Ahmad., G.(2012) "Development of a noninvasive continuous blood pressure measurement and monitoring system", Proceedings of the International conference on ICIEV, pp. 1085-1090.

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Panagopoulos., C,

Pavlatos., M, and Papakonstantinou., G. (2015) "An Embedded

Microprocessor for Intelligent Control," Journal of Intelligent and Robotic Systems, vol. 42, pp. 179-211. Richard., O.(2008). ”Remote control system using infrared technology based on 8052 microcontroller", Electron. Technol., vol. 45(10), pp.68 -70. Savanya., M, Pamela., D.(2012). “A real time IMC tuned PID controller for a DC motor”, International Journal of recent technology and engineering (IJRTE), Vol. 1(1), April 2012, pp. 65 - 70. Vaibhav., B. and Pawan., W. (2013). “A secured dual tone multifrequency based smart elevator control system," International Journal of Research in Engineering and Advanced Technology, Vol. 1(4), Issue 4. pp. 34-46. Xiaodong Xia.(2011). “Based on single chip microcomputer remote wireless control system design”. Coal Mine Machinery, vol. 32 (8), pp. 202-204.

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