Development Of A Data Logging System - Lab Report Example

TITLE: DEVELOPMENT OF A DATA LOGGING SYSTEM Introduction The process of gathering information for the future application is known as logging. A data logger can be defined as a system that holds records over a given period about the sensor's environment. Any data acquisition system is meant for gathering information from a sensor, storing and analyzing it to ensure the environment of the sensor is maintained as per the given set points in the control system. This allows the user of the system to be able to view the information in real time. The three main components of a data loggers are a sensor, a storage device and finally a microcontroller (Rosiek et al. 2008). The data loggers are designed in such a way that they have a large inbuilt memory that allows them to hold data for a considerable long period. This memory may be in the form of flash memory or static which usually has its own backup. Real time clocks are inbuilt in data loggers that enable them to be able to show the actual time through which data was recorded. Type of information that is gathered by a data logger is usually determined by the user. Some of their advantages include the ability to operate without computers as well as being available in different sizes depending on the preference of the user (Rosiek et al. 2008). Temperature is a constantly changing parameter that can be measured by use of different types of sensors. All of the sensors deduce the change in temperature through variation in some physical characteristics in the environment. During measurements however one should ensure the thermocouples temperature is equal to that of the environment. However is some situations the measuring instrument may lead to the development of a temperature gradient which leads to different readings of the actual system and the device temperature. In such a scenario the temperature measured varies with the heat properties of the surrounding (Rosiek et al. 2008). The main objective of this research work is to develop a data logger that can be used to store temperature measurements records. To be able to meet our primary objectives we have to design a small portable, viable and reliable data logger. The design is a microcontroller based data logger capable of taking different temperature readings from the input channels. The design receives data from an external sensor and stores it in the SD card as its external memory. An integrated liquid crystal display may or may not be used with the data logger for the purpose of real-time data display. In this work, the temperature readings given by the different channels of the data logger were compared to readings of a standard clinical thermometer. This helps in analyzing the most accurate channel of the data logger (Zhang et al. 2009). Equipment used Temperature sensor This was an essential equipment as it was useful in measuring the temperature changes in the environment and transferring the data to the data logger with the help of data cables. In our design, the type of temperature sensor that was utilized was the RTD thermocouple sensors. The tip sensitive isolated spring loaded RTD was used in the design. The design has high sensitivity due to the characteristics of its sensitive elements that include platinum, copper and nickel components. The sensor has the following specifications temperature range of -50 degrees to-260 degrees. It made of the probe, Holder, and the connection head. These components are mainly made of steel material. The sensor has a time constant of 0.2 seconds (Soloman, 2009). Fig 1: Illustration of the type of temperature sensor to be used USB cable This refers to the equipment that will be used to transfer signals from the sensor to the data logger. For this design, the cable required was a reversible type that had higher data transmission rates. This will ensure that the signals from the sensors are conveyed to the data logger within the shortest time possible (Benghanem 2009). Fig 2: Illustration of the USB cable used in our design that provided the required connection to the data logger as well as the SD card reader. Micro SD card This provided the storage media for all the required codes and collected information. It was essential in keeping a backup of the data recorded by the data logger. The data was recorded in a text file format (Benghanem 2009). Fig 3: micro SD disk Microcontroller The type of microcontroller which is responsible for the analysis of the data signals from the temperature sensor in our design.. the type of microcontroller chosen for this design is the OLIMEX Pinguino OTG PIC32 Microcontroller. This was the preferred type due to some of its unique features described below. It has a lower power consumption compared to the other available designs in the market. Has a special type of connector allowing the use of many modules that are currently existing. It also has mini cable USB connector that comes along with it when purchased (Malinowski et al. 2011). Fig 3: Illustration of the type of microcontroller used in the design. Method In this step, the first thing was to access the UECIDE programming language and open it. It was the application to help us in developing a code that will help the microcontroller to collect the temperature signals from the temperature sensor and analyze them. Since we had not installed it, we followed the required steps to install the program successfully. The program was instructed on how to locate the library as well as the sketches necessary for the experiment. Program code to guide the microcontroller to execute the signal processing from the temperature sensor was then developed (Benghanem 2010). We took some class tutorials on programming before doing the final code for the microcontroller. The general outline of our code is as shown below Function Void setup ( ) { // sensor type, serial node, sd card and microcontroller } // and avoid loop ( )} // the code to rerun continuously was put here. } Results The following tables show the experimental results. The temperatures from the three channels were compared to that taken by a clinical thermometer. Time (Minutes) Standard Temperature (0C) Ch1 0C Ch2 0C Ch3 0C 8:05 37.9 36 00 00 8:10 37.9 36 00 00 8:15 37.9 36 38 00 8:20 37.9 36 38 00 8:25 37.9 36 38 00 8:30 37.9 36 38 37 8:35 37.9 37 38 37 8:40 37.9 37 38 37 8:45 37.9 37 39 37 Table 1: readings taken at room temperatures. Time in minutes Standard temperatures in oC Channel 1 oC Channel 2 oC Channel 3 oC 8:00 37 00 8:30 37 34 35 35 9:00 37 35 36 36 9:30 37 34 35 35 10:00 37 34 35 36 10:30 37 35 36 36 11:00 37 36 37 36 11:30 37 36 37 36 12:00 37 36 36 37 Table 2: readings taken at environmental temperatures From the results, the accuracy of t individual channels were analyzed. Accuracy can be defined as the extent to which a measured value is close to the correct value. Channel 2 was found to be more close to the accurate standard values with a slight deviation of only 0.1%. The error in channel 1 was 1.9% while that of channel 3 was 0.9%. From the table, we can see that the second channel is more stable in its readings as compared to the others. Therefore after the full design of our data logging system, we found that the second channel was the most accurate in the recording of temperature signals as its values had the least deviation from the standard values in the given environment (Kumar et al. 2011). Block diagram of the data logger Data acquisition: this refers to the temperature sensors that will get signals from the environment that will be sent to the data logger. Online analysis: this refers to the process through which the data is pre-analyzed before being storage. Logging: the analyzed data is stored including all the required formats Offline analysis refers to the post-storage analysis that is done to the data. Fig 5: summarized block diagram of the data logging system ( note the display unit is optional) Advantages The designed data logger has several advantages which include the following: its operation will not interfere in any way with the user performing their respective tasks. This design can operate on its own without the help of a computer however one can also decide to use the computer. It is a multichannel type of data logger (Soloman, 2009). Conclusion At the end of the study, a multi-channeled data logger has been developed at a cheaper cost and a smaller size. The data logger was able to present real-time results of the temperature readings detected by an RTD temperature sensor. With only three channels the designs a simple one to use as compared to loggers with more than eight channels. The required step by step procedure for development of microcontroller based system that can be used to measure temperatures. Correct analysis of the component of the system as well as its design has been accomplished. The results have shown that the system has the good level of accuracy with channel 2 of the data logger being the most preferred regarding precision, accuracy and reliability of its readings. Having the data logger exposed to different conditions proved that the design can effectively work in any environmental conditions. REFERENCE Rosiek, S. and Bates, F.J., 2008. A microcontroller-based data-acquisition system for meteorological station monitoring. Energy Conversion and Management, 49(12), pp.3746-3754. Zhang, J.Z. and Chen, J.C., 2008. Tool condition monitoring in an end-milling operation based on the vibration signal collected through a microcontroller-based data acquisition system. The International Journal of Advanced Manufacturing Technology, 39(1), pp.118-128. Benghanem, M., 2009. Measurement of meteorological data based on the wireless data acquisition system monitoring. Applied Energy, 86(12), pp.2651-2660. Malinowski, A. and Yu, H., 2011. Comparison of embedded system design for industrial applications. IEEE transactions on industrial informatics, 7(2), pp.244-254. Benghanem, M., 2010. RETRACTED: A low-cost wireless data acquisition system for weather station monitoring. Renewable Energy, 35(4), pp.862-872. Soloman, S., 2009. Sensors Handbook. McGraw-Hill, Inc. Kumar, N.S., Saravanan, M. and Jeevananthan, S., 2011. Microprocessors and Microcontrollers. Oxford University Press, Inc. Read More

gn is a microcontroller based data logger capable of taking different temperature readings from the input channels. The design receives data from an external sensor and stores it in the SD card as its external memory. An integrated liquid crystal display may or may not be used with the data logger for the purpose of real-time data display. In this work, the temperature readings given by the different channels of the data logger were compared to readings of a standard clinical thermometer. This helps in analyzing the most accurate channel of the data logger (Zhang et al. 2009). Equipment used Temperature sensor This was an essential equipment as it was useful in measuring the temperature changes in the environment and transferring the data to the data logger with the help of data cables.

In our design, the type of temperature sensor that was utilized was the RTD thermocouple sensors. The tip sensitive isolated spring loaded RTD was used in the design. The design has high sensitivity due to the characteristics of its sensitive elements that include platinum, copper and nickel components. The sensor has the following specifications temperature range of -50 degrees to-260 degrees. It made of the probe, Holder, and the connection head. These components are mainly made of steel material.

The sensor has a time constant of 0.2 seconds (Soloman, 2009). Fig 1: Illustration of the type of temperature sensor to be used USB cable This refers to the equipment that will be used to transfer signals from the sensor to the data logger. For this design, the cable required was a reversible type that had higher data transmission rates. This will ensure that the signals from the sensors are conveyed to the data logger within the shortest time possible (Benghanem 2009). Fig 2: Illustration of the USB cable used in our design that provided the required connection to the data logger as well as the SD card reader.

Micro SD card This provided the storage media for all the required codes and collected information. It was essential in keeping a backup of the data recorded by the data logger. The data was recorded in a text file format (Benghanem 2009). Fig 3: micro SD disk Microcontroller The type of microcontroller which is responsible for the analysis of the data signals from the temperature sensor in our design.. the type of microcontroller chosen for this design is the OLIMEX Pinguino OTG PIC32 Microcontroller.

This was the preferred type due to some of its unique features described below. It has a lower power consumption compared to the other available designs in the market. Has a special type of connector allowing the use of many modules that are currently existing. It also has mini cable USB connector that comes along with it when purchased (Malinowski et al. 2011). Fig 3: Illustration of the type of microcontroller used in the design. Method In this step, the first thing was to access the UECIDE programming language and open it.

It was the application to help us in developing a code that will help the microcontroller to collect the temperature signals from the temperature sensor and analyze them. Since we had not installed it, we followed the required steps to install the program successfully. The program was instructed on how to locate the library as well as the sketches necessary for the experiment. Program code to guide the microcontroller to execute the signal processing from the temperature sensor was then developed (Benghanem 2010).

We took some class tutorials on programming before doing the final code for the microcontroller. The general outline of our code is as shown below Function Void setup ( ) { // sensor type, serial node, sd card and microcontroller } // and avoid loop ( )} // the code to rerun continuously was put here. } Results The following tables show the experimental results. The temperatures from the three channels were compared to that taken by a clinical thermometer. Time (Minutes) Standard Temperature (0C) Ch1 0C Ch2 0C Ch3 0C 8:05 37.

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