Design of Portable Data Logger for Water Department

Transcription

1 Design of Portable Data Logger for Water Department Suresh Gohane, 2 Pranjali Jaumle, 3 Jayshree Dhore, 4 Rushi Longadge 1,2,3 Assistant Professor, Department of Electronics and Telecommunication Rajiv Gandhi College of Engg. & Research, Nagpur 4 Assistant Professor, Department of Computer Science and Engg G. H. Raisoni Academy of Engineering Abstract - Water Department is a firm which takes care and manages overall water supply system throughout the city. The firm is undergoing some problems regarding enormous complaints from customers about the water supply like high amount of dissolved salts, improper flow of water, improper pressure of water etc. such complaints in reality were found to be fake. Such complaints indirectly puts question mark on service providing capability of the firm. So to check whether such complaints are real and if so, than taking necessary steps so as to improve their service providing capability,the firm needs such a system that can record the parameters of water supply system day wise like amount of water flowing, amount of dissolved salts, start and stop time of water supply. Keywords Flow Sensor, Pressure Switch, TDS Sensor, Logging. 1. Introduction Customers usually make complaints regarding water supply system for ex. Improper flow, low or improper water pressure, displaying more units compared to actual etc. such complaints are registered with a tendency to avoid the payment of bills which creates a huge loss to department. Such complaints when actually analyzed were found to be false. These complaints not only put question mark on service providing capability but also may harm the reputation. Water Department which will be able to maintain log of water supply system parameters like 1. Start and stop time water supply. 2. Maximum and minimum flow. 3. Maximum and minimum TDS (Total dissolved solids) 4. Amount of water supplied a day. This data logger will automate the system and will reduce error, also will make the process simpler, cost effective and reliable. The data logger which we designed is microcontroller based and for determining parameter values sensors will be used. These sensors will be interfaced with microcontroller and suitable software is developed which takes signals from sensors and further process it. 2. System Block Diagram The conventional methods which are being used by Water department to analyze performance of water supply system were found inefficient, the instruments which are being used are heavy, costly and requires manual operation also log is maintained manually so there may be chances of errors. By using such method not only time but also money is wasted. To make the overall process efficient we came to idea of designing and implementing portable data logger for Fig 2.1 System block diagram

2 416 System consists of consists of: 2.1 Pressure Switch These are the simple electro- mechanical devices. Widely used to start or stop the motors, these switches are available in number of dimensions and sizes to choose from. It operates on the following basic principle: When a change occurs in pressure on low pressure side of an elastic diaphragm, it moves transmitting a force to a pre calibrated snap switch. Diaphragm motion is resisted by a calibrated spring inbuilt in the micro switch that determines the range of the switch. 2.3 TDS Sensor TDS stands for Total Dissolved Solid. This sensor will analyze the conductivity of water. The conductivity of the water depends upon the number of ions (salts/solutes). By determining the conductivity of water, the amount of dissolved salts can be predicted. The TDS sensor consists of three major sections: 1) Oscillator Block 2) Amplifier Block 3) AC to DC converter Oscillator Block Wein bridge circuit is used in for Oscillator for TDS sensor. Oscillator is used for providing sustained oscillations. The oscillating frequency is around 25 KHz. And its amplitude is limited to 5.6 volts. The output of Oscillator is given to gain loop section. This signal will act test signal Amplifier Block 2.2 Flow Sensor Fig. 2.2 Pressure Switch It is a Hall Effect magnetic sensor whose output is a pulse signal. It consists of a plastic valve body, a water rotor & a Hall Effect sensor. This sensor sits in line with your water line and uses a pinwheel sensor to measure how much liquid has moved through it. The pinwheel has a little magnet attached, & there s a Hall Effect magnetic sensor on the other side of plastic tube that can measure how many spins the pinwheel has made through the plastic wall. Two probes are drawn which will be placed in water and which will detect the conductivity of Water. These probes are given to the gain loop section of amplifier which is having the gain Rf/R1 and R1 depends upon the conductivity of water. Hence the AC signal is amplified according to gain decided by R1 which is the function of conductivity of Water AC/DC Converter The signals of Amplifier block will be AC signal. As microcontroller is digital device, it will detect digital signals only. Hence it is important to convert this AC signal into relevant DC level. This is done by this section. The main component of this section constitutes a Bridge Rectifier and filter circuit. Bridge rectifier is used as it is the most efficient among the rectifier circuits. Characteristics of Bridge rectifier are: Low PIV rating Most efficient among rectifiers with 81.2% efficiency Ripple factor is Fig.2.3 Flow Sensor Filter used is RC type filter. It is used for reducing the AC or ripple contents at the output of the rectifier.the microcontroller Atmega16 has inbuilt Analog to Digital

3 417 converter at port A. The filtered output will be directly given to one of the pin of port A. 2.5 Display In our system we are using liquid crystal display (LCD) which is basically a 16 X 2 LCD display. The display will show the value of all the three parameter i.e. amount of water flowed and amount of dissolved impurities, with start and stop time. Fig.2.4 Schematic of TDS Sensor 2.4 Microcontroller ATmega16 The ATmega16 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega16 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. It is the core element of system with following features: 1. It is 8 bit microcontroller K SRAM MHz clock frequency. 3. Flow Chart Fig.2.6 Liquid Crystal Display The actual working of the system can be understood by using the flow chart shown further. When the logger is fixed to consumer end we just have to set the date and time and that s all. As soon as the pressure switch sense the pressure it gives a signal to microcontroller and microcontroller starts reading the values of different sensors and starts logging maximum and minimum value of respective sensor. Fig.2.5 Pin Diagram of µc ATmega16

4 418 Fig.3.1 Flow Chart 4. Results The parameter value is stored in inbuilt memory of microcontroller. The log is maintained on daily basis throughout the week. These values will be available on LCD screen by pressing push button. 5. Conclusion Fig.4.1 Result By designing this data logger we will be able to keep a log of parameter values according to date and time of water supply system on weekly basis. This log can be used to study and analyze the overall performance of water supply system. This log will be

5 419 useful to Water Dept to take necessary steps to improve water supply system and thus will increase the service providing capability, also help in maintaining trust amongst its customers. References [1] Sakhi S.,Khettat A. Hanks M. Belhocine, M. designing of microcontroller based data logger published in Adaptive Science & Technology, ICAST nd International Conference dated Jan [2] Goulao V., Paulo R., Salvado J.,Martins G. presenting new data logger system to monitor the parameters of processes of industrial cooling system published in EUROCON - International Conference on Computer as a Tool (EUROCON), 2011 IEEE dated 2-4 April [3] Book Atmel AVR Microcontroller Primer: Programming and Interfacing by Steven F. Barrett (University of Wyoming) & Daniel J. Pack (United States Air Force Academy). Synthesis lectures on digital circuits & system. [4] Tutorial videos of programming & interfacing of Atmega16 from newbiehack.com. [5] Study material on Hall Effect Sensing & Application from sensing.honeywell.com [6] Data sheet of Hall effect based water flow sensor from hitectlogics.com. [7] Study material of low pressure switch from [8] Study of TDS sensor of projects from [9] Data sheet of ATmega16 from Atmel Corporation.