VIRTUAL LAB KIT GUDASALAMANI

Transcription

1 VIRTUAL LAB KIT 1 ROHINI HONGAL, 2 SANDEEP PATIL, 3 SURAJ PAWAR, 4 JYOTI PATIL, 5 RAJAT BAPURI, 6 SANTOSH KULKARNI, 7 SOURABH ALAGUNDAGI, 8 SANTOSH BAMMIGATTI, 9 SHREYA GUDASALAMANI Dept. of Electronics and Communication Engineering, B.V. Bhoomaraddi College of Engineering and Technology, Hubli- 31, India Abstract Technology has eased human life. Students who are responsible for many technological advents can also make use of this boon. Laboratory is a place where we gain practical knowledge. Students face a problem wherein they are not able to conduct the experiments at their homes due to unavailability of Oscilloscope, Audio Frequency Oscillator (AFO) and other electronic equipment. Also, due to the limited number of electronic equipment at laboratory, students are forced to conduct the experiments in a group. This paper which presents the idea virtual lab kit solves this problem as it includes all the necessary equipment like Oscilloscope, AFO, Digital Multi-meter (DMM), DC power supply and IC tester. The paper includes both hardware and software components. Hardware components consist of an Arduino board, a Bluetooth module and other components. Software components consist of an android app that controls the hardware kit. In this paper, we develop the software code for the desired functioning of the Arduino UNO and the Android application. We also define the circuit models to be constructed to perform the desired functions. Finally, we evaluate the result from the model circuit, which tests how well our application can overcome the existing problem. The tests were conducted and the results were compared with standard equipment which desired results (Deviation of ±5%). The Virtual lab kit a cost-effective, user friendly and an all-in-one kit. Keywords ammeter, Android, Arduino, Bluetooth, continuity, diode, ohmmeter, oscilloscope, transistor, voltmeter. I. INTRODUCTION Consider a scenario in the near future where a person sitting in his room is able to construct a simple communication system using a hardware kit and an Android device. He can tweak the frequency of the carrier signal, simultaneously analyze the output, check the voltages/currents at any point in the circuit, test the ICs used, all by using the Virtual lab kit and the Android application. In the present laboratory condition, students work with bulky equipment that are expensive. However, imagine in the near future, when simple commands given to the commonly used Android devices help them to perform any electronics based experiment anywhere. The Android device transmits commands to the Arduino board via Bluetooth. The Arduino board receives commands via Bluetooth module. The board then compares the obtained command with the standard pre-stored commands and does the necessary function. The result is then displayed on the Android device. This kit is a boon for students who can t afford to buy the Oscilloscope/AFO. Fig1. Block diagram of Virtual lab kit along with Android device II. HARDWARE A. Arduino UNO The Arduino UNO is a microcontroller board based on the ATmega328. It contains everything needed to support the microcontroller; when connected to a USB cable or powered with an AC to DC adapter or battery. It has 14 digital input/output pins, 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. The UNO does not use the FTDI USBto-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB to serial converter. [1] Can such an integrated kit be created? Key considerations lies in answering the questions regarding the integration of hardware and software used. 126 Fig2. Arduino Board

2 B. Features 1. Microcontroller ATmega Operating Voltage 5V 3. Voltage (recommended) 7-12V 4. Input Voltage 6-20V 5. Digital I/O Pins Analog Input Pin 6 7. DC Current per I/O Pin 40 ma 8. DC Current for 3.3V Pin 50 ma 9. Flash Memory 32 KB 10. SRAM 2 KB 11. EEPROM 1 KB 12. Clock Speed 16 MHz C. Bluetooth module HC-06 Bluetooth is a wireless technology standard for exchanging data over short distances from fixed and mobile devices, and building personal area networks. It uses shortwavelength UHF radio waves in the frequency band from 2.4 to GHz. Bluetooth is managed by the Bluetooth Special Interest Group (SIG) and was standardized as IEEE [2] F. Eclipse IDE Eclipse is an integrated development environment (IDE). It contains a base workspace and an extensible plug-in system for customizing the environment. Written mostly in Java, Eclipse can be used to develop applications. Eclipse SDK is free and open source software. [5] IV. METHODOLOGY G. Hardware The following are the logic used to implement the functional blocks- 1) Ohmmeter Two resistors are used as standard (whose resistance is known) to measure the test resistance. A simple voltage divider circuit is used to find the voltage across standard resistor. This voltage is sent to Arduino analog pin that gives the corresponding digital value. This value is used to find the value of test resistance. [6] Fig4. Ohmmeter Fig3. Bluetooth module HC-06 D. Software features 1. Default Baud rate: 38400, Data bits: 8, Stop bit: 1, Parity: No parity, Data control: has Supported baud rate: 9600, 19200, 38400, 57600, , and Given a rising pulse in PIO0, device will be disconnected. 3. Status instruction port PIO1: lowdisconnected, high-connected; 4. Auto-connect to the last device on power as default. 5. Permit pairing device to connect as default. 6. Auto-pairing PINCODE: 0000 as default.[3] Fig5. VLK ohmmeter v/s conventional DMM Reference resistor 2.2K III. SOFTWARE E. Arduino IDE The Arduino Integrated Development Environment (IDE) is a cross-platform application written in Java, and derives from the IDE for the Processing programming language and the Wiring projects. [4] The programs to perform desired functions are written in the Arduino software. Fig6. VLK ohmmeter v/s conventional DMM Reference resistor 100K 127

3 2) Diode tester Two digital pins D1 and D2 of Arduino are used to test the diode. Initially D1 is made HIGH, D2 is read then D2 is made HIGH and D is read. If the readings are 1 and 0, or 0 and 1, the diode is good. [7] 5) Led tester Logic of LED tester is very simple, just connect the positive terminal of the LED to the Vcc and negative terminal to the ground if LED is healthy it glows, if it is dead it doesn t glow. To protect LED we have provided the 220 Ωm resistance which is connected to Vcc. Fig7. Diode tester 3) Continuity tester Two digital pins D1 and D2 of Arduino are used to test the continuity. Initially D1 is made HIGH, D2 is read. If D2 is HIGH then the circuit completes. Fig 11. Led tester Fig8. Continuity tester 4) Voltmeter Arduino only supports reading from 0v to 5v maximum. But a typical DMM must measure at least from -20V to +20V. Therefore we have used differential Amplifier to convert -20V - (+20) V to - 5V- (+5) V and OpAmp 2 to convert -5V- (+5) V to 0V - 5V as shown in the circuit diagram below. The voltage is given to Arduino that measures it. [8] 6) Ammeter To measure the current an Op-amp is used to convert the current into equivalent voltage. Then this voltage is given to Arduino where it is processed and current is calculated. [9] Fig12. Ammeter 7) Transistor Beta value calculator To test the transistor a constant current I b is given to its base. Then the corresponding collector current is measured using Arduino and it is processed to calculate h fe as I c /I b. [10] Fig9. Voltmeter Fig10. VLK voltmeter v/s conventional DMM Fig13. Transistor Beta value calculator 128

4 TABLE 1 Testing of different transistors V. HARDWARE SOFTWARE INTERFACE PNP Transistor V ce (V) I b (ua) I c (ma) H fe 2N BC NPN Transistor V ce (V) I b (ua) I c (ma) H fe 2N2222A BC107B BC547B BC Considering R base = 430kΩ H. Software The software module consists of an Android Java and XML code that helps in integrating the hardware kit with the Android device. The code tries to establish a connection with the Bluetooth module in the initial stage. Further, based on the users options, the respective commands are sent to the hardware kit and the corresponding functional blocks are triggered. The Algorithm is as follows- 1. Create the required package. 2. Import the various classes. 3. Create declaration of the layout for the app such as buttons. 4. For each of the buttons a new activity is created. 5. Based on the feature selected, which is identified by click listener various operations are done. 6. Assume Oscilloscope is selected. 7. If user clicks on Bluetooth connect, set your Bluetooth device on and Scan for other Bluetooth devices. 8. Query the local Bluetooth adapter for paired Bluetooth devices. 9. Connect to other devices through service discovery. 10. Transfer data to and from other devices. 11. Plot the graph on the android phone based on the values received from the kit. 12. On selection of stop stream, stop the plotting of graph on the screen. Similar procedure is followed for other features like AFO, DMM, and IC Tester etc. In this paper the hardware kit is interfaced with the android device via Bluetooth. The data is wirelessly exchanged between the android device and Arduino. In order to interface with Arduino board Bluetooth module is required. The application framework provides access to the Bluetooth functionality through the Android Bluetooth APIs. The application is connected wirelessly to other Bluetooth devices with the help of API. VI. WORKING The command given to the Android application is transmitted via Bluetooth. The HC- 06 Bluetooth module connected to the Arduino Uno board receives the command. The Arduino Uno board compares the received command with the pre-stored commands and performs the desired operation. The corresponding output/waveform is displayed on the android device. VII. MOBILE LAYOUT Fig14. App first look Fig15. Oscilloscope output on app VIII. SIMULATION AND RESULTS I. Simulation Simulation of Virtual lab kit is done using software PROTEUS ISIS. The functioning of each equipment are tested and verified. 129 Fig16. Simulation of the circuit

5 measuring equipment. To conclude, Virtual lab kit is a cost-effective, user friendly and an all-in one kit. FUTURE SCOPE Fig 17. App simulation J. Breadboard implementation We implemented the Virtual lab kit circuit on the breadboard and tested all operations of equipment using the application. In the near future, the Virtual lab kit, because of its cost-effectiveness, easy to use, precise and all-in-one nature will been seen in each and every laboratory which once had the bulky, complicated and discrete equipment. Also, due to its affordable pricing, Virtual lab kit will be commonly seen with students and with each and every person who performs electronics-based experiments. The Virtual lab kit can also be customized for specific applications. The Virtual lab kit can be further developed to increase its accuracy for the medical applications so that the medical services become affordable to all. ACKNOWLEDGMENT Fig 18. Bread board implementation of the circuit It is a great pleasure to express our deep sense of gratitude and indebtedness to the institute B.V.Bhoomaraddi College of Engineering and Technology, Hubli, our HOD Dr. Uma Mudengudi and our guide Prof. Rohini Hongal for their support. REFERENCES Fig19. App implementation on android device CONCLUSION We successfully constructed and implemented functions of the Virtual lab kit like IC Tester, DMM etc. The DMM features were implemented and tested except Ammeter. Voltmeter measurement ranges from -20V to +20V, while resistance measurement ranges from 1Ω to 1 MΩ. The Ammeter will be designed to measure the range 1mA to 1A. Testing of the complete kit is done by comparing it with the existing equipment (DT830D digital multimeter). The results obtained deviates by 5% of that of the results obtained by standard [1] Arduino Uno[Online]. Available: [2] Bluetooth[Online]. Available: [3] Wireless[Online]. Available: [4] Arduino[Online]. Available: [5] Eclipe[Online]. Available: [6] Milen. Digital multimeter shield for Arduino[Online]. Available: [7] R-B. (1995, Oct. 10). Microcontroller based Diode and Bipolar Junction Transistor (BJT) tester[online]. Available: [8] Ramakant A. Gayakwad, Op-Apms and Linear Integrated Circuits, Fourth edition, pp [9] Milen. Digital multimeter shield for Arduino[Online]. Available: [10] Mike Cook. Transistor tester[online]. Available: html 130