IJECT Vol. 3, Issue 4, Oct - Dec 2012 ISSN : 2230-7109 (Online) | ISSN : 2230-9543 (Print)

Monitor-and-control System Design for Supermarket Fresh Area Based on ZigBee1Nagarjuna Badigunchala, 2R. Giri Prasad

1VLSI & ES Branch, Prakasam Engineering College, Kandukur

2Dept. of ECE, Prakasam Engineering College, Kandukur

Abstract

This paper describes system for monitoring and controlling super market fresh area based on ZigBee. By observing different supermarkets, Supermarkets can’t monitor the temperature and humidity around food of fresh area in our country effectively. This thesis designs a hierarchical topology central monitoring systembased on ZigBee wireless sensor network (WSN). In this system surveyed area temperature and humidity can be automatically monitored and controlled. The monitoring nodes, with the Xbeepro, can collect and upload temperature and humidity data to the Management Centre, management Centre displays and processes the data, through the central node and the RS -232 interface. Monitoring nodes automatically starts the alarm system and the regulating system, If the collected data exceeds the threshold. Regulating system could be automatically shut down, while the data is lower than the standard value. Nodes work in the regular query power saving mode. Power is obtained from button cells conversion through MAX 232. The results reveal that due to its lowcost, low power and flexible networking construction WSN system has the potential for field applications and flexible networking construction WSN system has the potential for field applications.

Also the store room data also we can get by RFID mechanism, the item added to store

or item deducted from store is done by maintaining RFID data in system. Each and every product here is attached with RFID details so adding item and removing can done easily by RFID technology in this project.

Keywords

ZigBee, Supermarket Fresh Area, Monitoring, Wireless Sensor

Network

I. Introduction

Generally, in super markets fresh food (Meat, seafood, vegetables, fruit, etc) are put on thesale desk by spreading through air conditioningat the end of the counter or capping with ice cluster on the counter. These approaches may cause fresh food heated at top side while cold on the bottom side, because temperature and humidity uneven. Due to uneven temperature and humidity, food goes bad easily and causes economic losses. To avoid this super market staff has to add air conditioning or replace ice cluster or spray mist from time to time. Adding air conditioning or spraying mist is

manipulated by the staff with experience, Because of the lack of effective monitoring system. Temperature and humidity parameters of fresh food are tested by hand-hold instrumentation regularly. This technique has low efficiency, and is more difficult to achieve a real-time automatic detection and intelligent control.

This increases difficulties of preservation for fresh food and difficultyof the staff’s work.

ZigBee technology is a two-way wireless network technology. ZigBee is short distance, low complexity, low power and low-cost. It is developed based on IEEE 802.15.4 wireless standards. ZigBee nodes expansion range is 65536. ZigBee consumes less power because it works in energy saving mode the two batteries supply energy up to 1 year and a half or so.

The system is made up of node modules which are based on high performance single chip CC2430 that integrates ZigBee wireless network technology, and the modern management center. The Management Center canmonitor temperature and humidity of nodes located in different parts of the fresh foodarea by the implementation of platform of Software and hardware. The proposed system has an automatic alarm and regulation system. The host displays warning information on the screen, immediately sendsa warning instruction to the corresponding node to drive the warning module to alarm toalert market staff, If the detected data information exceeds the set threshold (for avariety of preservation condition, the threshold may be set separately to differentfresh food. In the system, the threshold of temperature of fresh meat is set as 4ºC. It starts the regulation module and opens the solenoid valve to automatically adjust temperature and humidity around the food through air conditioning or water mist. The management center sends stop regulating instruction to the corresponding node to

close regulation module, While the temperature or humidity reaches the preset standard value (in the system, the temperature standard value of the meat is set to 0 ºC. so that it achieves the purposeof automatic detection and intelligent control.

II. Hardware Configuration

Fresh food distribution, characteristics of ZigBee technology system uses tree topology structure; Figure 1 is the structure diagramof the monitoring system. It contains monitoring nodes, router nodes, the control center node and the Management Center (PC). All these nodes are based on the CC2430 thatis a standards compliant SOC ZigBee chip based on IEEE802.15.4.Leaf nodes of the network are monitoring nodes. Monitoring nodes mainly responsible to collection data,sound and light alarm and the temperature and humidity adjustment. Network management and data forwarding is the responsibility ofrouter node. Router node can guarantee connectivity and robust for a larger network. Responsibility of central node is coordination of ZigBee network. Central nodeis equivalent to the trunk node in the network. Central node is responsible to management node, processing data and external interfaces. System’s central controller is PC host. PC host is connected to the central node through the RS-232interface, responsible to analysis, processing and conditioning control data.

Fig. 1: Structure Diagram of Supermarket Fresh Area Monitor

System

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ISSN : 2230-7109 (Online) | ISSN : 2230-9543 (Print) IJECT Vol. 3, Issue 4, Oct - Dec 2012

Supermarket fresh food areas generally are divided into several small sale units. Theseareas are close to each other and the numberis big, which requires more sensor nodes. Miniaturization and low-power are required for nodes to facilitate the arrangement and save consumption. For proper working sensor nodes are placed in a humid environment a higher reliability of the hardware is required. Supermarket fresh area monitor system the management center has a graphic warning function. Monitoring nodes are equipped with alarm module and regulation module, to increase the field alarm and automatic control.

A. Monitoring Node Design

Wireless transceiver module (including themain chip CC2430, the clock unit and the RF antenna unit), the sensor module, alarmmodule, regulation module and power supplymodule are parts of Monitoring nodes. Figure2 represents schematic. Core of the hardware module is CC2430. CC2430 is manufactured by TI. CC2430 is an enhanced 8051MCU integrated with RF transceiver. Itis working in 2.4GHz band, low-voltage power supply (2.0 ~ 3.6v), low power consumption (receiving data is 27mA, sending data is 25mA), and the maximum transfer rate of 250KB/s. CC2430 clock unit has two working modes. One working mode is 32MHz to provide normal power modefrequency. Other working mode is 32.768MHzfor low-power operating frequency. Antennafeeder circuit and impedance matching circuit are the parts of Antenna module. Antenna module maximum transmission distance is up to 100m.

Fig. 2: Schematic of Monitoring Node

Here we are using Sensor module for getting temperature and humidity, signal conversion and processing. SHT11 sensor isproduced by the Sensirion of Swiss, with I2C bus interface and full digital

calibration of the relative temperature and humidity considering following factorslike accurate dew point measurement, ultra-fast response

Time(less than 4s), ultra-small size (7.5*5*2), the sensor can simultaneously measure the relative humidity and temperature; and can be completely submergedin water. The parts of power module are two 3V button batteries, MAX 232 chip, transistor bc547 and

other components. Two 3V coin cell batteriesare collected to give 6V reference Voltage. This 6V reference voltage is transformed to gain 3.3v operating voltage by MAX 232.FZT749 PNP transistor is used to expand the flow of current, with the maximum outputcurrent up to 1A. By the above process the node module could meet the demand of electricity supply. For saving energy if theoutput voltage is less than 2.96V, MAX 232 can automatically cut off the output voltage.

CC2430’s P1_0 pin is externally collected a buzzer to form alarm module. If the sensor node detects a alarm instruction, fed back from PC, P1_0 could generate a switching signal to trigger the alarm buzzer.

Opt coupler TLP521, driver transistor 2N5551, Relay DZ-122 and solenoid valve are parts of regulating module If P0_1 receives low trigger signal, the opt coupler starts to work, NPN transistor is in a conduction state, a current flows through the relay, then the solenoid valves starts to work. Temperature or humidity is adjusts by Air conditioning or water flows through the open valve. AC

220V supplies solenoid valve power. Relay and opt coupler are

12V and 5V, which are gained by 220V transformer, rectifier, filter, regulator.

B. Central Node and Routing Node Design

The wireless communication module of the twonodes is same as the monitoring node. Wireless communication module consisting of the wireless transceiver module and the external circuit. Difference between monitoring node and wireless communication node is that in wireless communication module main chip CC2430 connects with a serial communication interface RS-232 through which Management Center communicates.

MAX3232 chip is selected; the working voltage is 3.3V which can achieve TTL level converter with two-way RS-232 level.Router nodes hardware module is same as the sensor node.

Fig. 3: Structure Diagram of Center Node

III. Software Design

Modular design is used for software design. The main module is divided into upper and lower machine module. Management center module is the Upper machine module. ZigBee node module is the lower machine module. ZigBee node module includes the sensor module, the central node module, and routingnode module. The whole system works in timing query mode in normal conditions of temperature and humidity. Monitoring nodes upload the collected data only when receive

a query command. Other most of the time theywill be in energy saving state.

A. Software Design of PC Module

System management center is PC. To wake the nodes from the close state the host sends wake-up instructions to each node via RS-232 bus after the system is powered. Each node sends a response message to the management center through the center

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IJECT Vol. 3, Issue 4, Oct - Dec 2012 ISSN : 2230-7109 (Online) | ISSN : 2230-9543 (Print)

node in success condition. Management Centrewill send a query instruction to each node every 1 minute after confirming that the nodes have been waked up. This checks whether the node works normally. And at the same time, PC sends a read data instruction to the node to read the node data. Management center automatically records and displays data from monitoring nodes, also compares with the threshold after receiving the data. Corresponding display bar of node appears warning message, If a monitoring node data are greater than the threshold. Also PC will send a warning instruction to the node. Then it will receive real-time data from the node. It ceaselessly compare with the set standard value. PC will send a stop regulating instruction to the corresponding node to automatically turn offregulator module, if the data is less than the standard value.

B. Software Design of Monitoring Node Module

Terminal node of the network is monitoring node. If monitoring node is wake up. it willautomatically initialize hardware and be self-organized into ZigBee networks, and then read the instructions from the central node. Monitoring node will collect the data and send it and its address to the host through the central node if it reads the query instruction. it will immediately startthe alarm module to remind staff, start the regulation module, and start air or water valves to automatically adjust the temperature and humidity around the food through the relay to open the solenoid valve, If it receives the alarm instruction.The alarm module will be shut down, after successfully

Fig. 4: Flow Chart of the Management Center

Starting regulating module. Every 10 seconds it will send the data information to the control center. it will immediatelyclose the regulator module If it receives the stop regulating instruction. Other time Nodes are in energy saving sleep state.

Fig. 5: Flow Chart of Monitoring Nodes

C. Software Design of Central Node Module and Routing Node Module

Fig. 6: Flow Chart of Center Nod

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ISSN : 2230-7109 (Online) | ISSN : 2230-9543 (Print) IJECT Vol. 3, Issue 4, Oct - Dec 2012

Connection point between the ZigBee network and the management center, playing Gateway roleis Central node. Node is waiting to receive information, after the node wake-up Initialization. This may be instructions from the management center or also may be data in other nodes. If a instruction, the central node will parse the command information, and then instruction is sent to the designated node, when receiving the data information from other nodes, central node will send them to management center. Enhancing network monitoringcoverage and stability is the responsibility of routing node module

IV. Conclusions

The arrangement of 12 monitoring nodes, two routing nodes, a central node and a central host in a local supermarket’s fresh meat sale counter will give the implementation of simulation tests. By Field testing, super-fresh meat sale counter’s temperature is 3.5ºC orso, humidity 78% or so, the communication distance of the monitoring node and routing node is 23m or so. Within the 15m range, even when there is interference of people walking around the supermarket, communication system, alarm system and regulation system still workcorrectly. As more points can be monitored, with more flexibility node layout, lower cost and with a real-time display and automatic alarm, adjustment function, the system can achieve reliable and efficient wireless intelligent monitoring for supermarket fresh food, which creates a certain condition for modern management of the supermarket.

V. Acknowledgments

We wish to thank professors and Associate professor of the department of VLSI & ES, ECEBRANCH of Prakasam Engineering College for their encouragement and support on our project.

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JiangYujian, Zhou Xiaoping,"Study on Shelf Life of MAP Packaged Pork under RefrigeratedCondition Food and Fermentation Industries 2003 (Chinese).

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DatasheetforSHT11(v2.0), 2003, [Online] Available: http:// www.sensirion.com

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