Final Project Report_Kartik Gandhi_2008A3PS150P Anupam Maurya_2007B2A3499P

Wireless Driver Cabin Display for Trailers

A

Report

ON

WIRELESS DRIVER CABIN DISPLAY

FOR TRAILERS USING ZIGBEE

By

Name of the Students ID No.

Kartik Gandhi 2008A3PS150P Anupam Maurya 2007B2A3499P

AT

Ingersoll Rand Engineering & Technology Centre, Bangalore

A Practice School-II Station of

Wireless Driver Cabin Display for Trailers using ZigBee

BIRLA INSTITUTE OF TECHNOLOGY & SCIENCE, PILANI

(December, 2011)


A

Report

ON

WIRELESS DRIVER CABIN DISPLAY

FOR TRAILERS USING ZIGBEE

By

Name of the Students ID No.

Kartik Gandhi 2008A3PS150P Anupam Maurya 2007B2A3499P

Prepared in partial fulfillment of the course

BITS C412/BITS C413 - Practice School II

AT

Ingersoll Rand Engineering & Technology Centre, Bangalore

A Practice School-II Station of

BIRLA INSTITUTE OF TECHNOLOGY & SCIENCE, PILANI


(December, 2011)

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ACKNOWLEDGEMENTS

We are grateful to Mr. K.S Ravichandran, Head – Advance Engineering Division India and Mr. Naveen Sankeshwar, Engineering Leader-Global controls & Enterprise Services, Bangalore for giving us this opportunity to work at Ingersoll Rand Engineering and Technology Centre, Bangalore. We are also extremely thankful to Mr. Nagaraj C.L. (Senior Software engineer – Enterprise Services) and Mr. Rishi (Technology Lead – Enterprise Services) for guiding and mentoring us. We had invaluable contribution from Mr. Rohit Acharya (Senior Software Engineer-Enterprise Services) who was directly involved in the project development. Mr. Raghu M.B. (Software Engineer-Enterprise Services) was instrumental with his constant guidance and support. We would like to extend our heartiest thanks to the entire Climate Solutions team for their warmth and for making us feel an integral part of the Ingersoll Rand, Bangalore family within no time

We are also grateful to Prof. G. Sundar, Deputy Director-cum-Dean (Practice School Division) for finding us eligible to enroll for the Practice School Program and for giving us the opportunity to work at Ingersoll Rand, Bangalore.

We are also thankful to Prof. Niranjan Swain, Dean, Practice School Division.

We also wish to express our deepest gratitude to Mr. Madhukar M.V. our Faculty-in-charge, who taught us everything about the program as well as for encouraging us to work our level best and make this program a success.

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BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE PILANI (RAJASTHAN)

Practice School Division

Station: Ingersoll Rand Engineering & Technology Centre Centre: Bangalore

Duration: 5.5 months

Date of Start: July 4, 2011

Date of Submission: December 5, 2011

Title of the Project: Wireless Driver’s Cabin Display using ZigBee

Student ID Student Name Student Discipline

2007B2A3499P Anupam Maurya B.E.(Hons.) Electrical & Electronics and M.Sc. Chemistry

2008A3PS150P Kartik Gandhi B.E. (Hons.) Electrical & Electronics

Name & Designation Mr. Nagaraj CL, Senior Software Engineer – Enterprise of the Expert: Service

Mr. Rishi, Tech Lead-Enterprise Service

PS Faculty: Mr Madhukar M.V.

Key Words: ThermoKing, BeeKit , ZigBee, UART, DATAPAC protocol

Project Area: Embedded Systems

Abstract: The ThermoKing, cold refrigeration trucks and trailers, a product of Ingersoll

Rand, has a controller in the trailer unit which is interfaced with many sensors receives

temperature and alarm information. The alarms are indicated through the status light

which a driver sees it in his rear view mirror and has to stop the vehicle and get down to

clear the alarm. This is inconvenient during rains, snow and storms and also time

consuming. To avoid this we intend to display the temperature and alarm notifications

in Driver’s cabin on an existing HMI called TSD currently employed in all ThermoKing

trucks and trailers. Temperature can be set and Alarms cleared by pressing buttons on

TSD. This we propose to do wirelessly using ZigBee wireless 802.15.4 standard.

Signature of Student Signature of PS Faculty

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Signature of Student DateBIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE

PILANI (RAJASTHAN)

PRACTICE SCHOOL DIVISION

Response Option Sheet

Station: Ingersoll Rand Engineering & Technology Centre Center: Bangalore

ID No. & Name(s): Anupam Maurya – 2007B2A3499P Kartik Gandhi – 2007A3PS150P Title of the Project: Wireless Driver’s Cabin Display for Trailers using ZigBee

Usefulness of the project to the on-campus courses of study in various disciplines. Project should be scrutinized keeping in view the following response options. Write Course No. and Course Name against the option under which the project comes.

Code No. Response Option Course No.(s) & Name1. A new course can be designed out of this

project.N.A.

2. The project can help modification of the course content of some of the existing Courses

N.A.

3. The project can be used directly in some of the existing Compulsory Discipline Courses (CDC)/ Discipline Courses Other than Compulsory (DCOC)/ Emerging Area (EA), etc. Courses

Applicable. EA

4. The project can be used in preparatory courses like Analysis and Application Oriented Courses (AAOC)/ Engineering Science (ES)/ Technical Art (TA) and Core Courses.

N.A.

5. This project cannot come under any of the above mentioned options as it relates to the professional work of the host organization.

Applicable

_________________ ________________ Signature of Student Signature of Faculty

_________________ Date: Signature of Student

_________________

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Signature of StudentDate:

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TABLE OF CONTENTS

S.No ContentsPage No.

1. INTRODUCTION 2

2. ABOUT ZIGBEE 4

2.1 Application 4

2.2 Basic Software Architecture 5

2.3 Reliability Measures offered by ZigBee 7

2.4 Security Measures offered by ZigBee 8

3. PRESENT TECHNOLOGY 9

4. PROJECT DESCRIPTION 10

4.1 UART Communication 10

4.2 Over the Air Communication 11

5. HARDWARE AND SOFTWARE TOOLS USED 12

5.1 Hardware 12

5.1.1 Freescale ZigBee Network Node: 13

5.1.2 Freescale ZigBee Sensor Node: 13

5.1.3 Freescale ZigBee Low Power Node: 14

5.2 Software 14

6. CONCLUSION 15

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7. FUTURE IMPROVEMENT IN THE PROJECT 16

8. REFERENCES 17

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1. INTRODUCTION

The objective of the project is ‘To set up a Wireless In-cabin display for the Trailer’s

Driver using ZigBee, to display Trailer’s Temperature and Alarm Notification.’

A brief about ZigBee, ZigBee is a specification for a suite of high level communication

protocols using small, low-power digital radios based on an IEEE 802 standard for

personal area networks. The technology defined by the ZigBee specification is intended

to be simpler and less expensive than other WPANs, such as Bluetooth. ZigBee is

targeted at radio-frequency (RF) applications that require a low data rate, long battery

life, and secure networking. ZigBee has a defined rate of 250 kbps best suited for

periodic or intermittent data or a single signal transmission from a sensor or input

device. The name ZigBee refers to the waggle dance of honey bees after their return to

the beehive.

ZigBee operates in the industrial, scientific and medical (ISM) radio bands; 868 MHz in

Europe, 915 MHz in the USA and Australia, and 2.4 GHz in most jurisdictions worldwide.

Data transmission rates vary from 20 to 250 kilobits/second.

The ZigBee network layer natively supports both star and tree typical networks, and

generic mesh networks. Every network must have one coordinator device, tasked with

its creation, the control of its parameters and basic maintenance. Within star networks,

the coordinator must be the central node. Both trees and meshes allow the use of ZigBee

routers to extend communication at the network level.

About the project, The Trailer units equipped with the Transport Temperature Control

Systems manufactured by Thermo King Corporation have a Human Machine Interface

(HMI) placed within them. This HMI is used to display many parameters of the

Refrigeration system. This project will wirelessly extend the Display of the Current

Trailer’s Temperature from the Controller in the Trailer to the Display in Driver’s Cabin.

Apart from this, refrigerator is also monitored continuously and if there is any abnormal

behaviour then this is intimated through displaying alarms. This wireless system will

intimate the type of alarm occurred. Which can be then cleared by the driver through

his TSD by pressing buttons. The Alarms will be cleared individually. We will also

provide the capability to set the Set Point temperature from the TSD. The value entered

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through TSD will be relayed down to Controller through ZigBee framework and set by

the controller.

An important parameter in HVAC systems is the Return Air temperature. This

parameter can’t be changed by the user. It can only be read. We will display the this

important parameter on the TSD.

The advantages of this feature would be:

Unfavourable weather conditions such as Heavy Rain, Snowfall, Storms will not

prevent the driver from assessing the Alarm status, thereby increasing the

Driver’s comfort

The driver will be intimated of the Alarm in the cabin itself and hence can carry

out rectification steps quickly.

Driver will no longer be disturbed as he will not have to look out for the Status

Light which starts blinking when an alarm occurs.

Wired communication between the In-cabin HMI and Trailer’s Controller can be

avoided using wireless ZigBee Communication.

This added feature will be add on the services provided and will increase user

interaction with the system. The project makes use of the prevalent technology

already in place and hence the original setup need not be modified.

Also the many more functionalities can be added in a similar manner which will

make the system more complete.

Figure1: A Block Diagram of Product implemented on Thermo King Trailer

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1.1 Business benefits

• No similar technology exists in the market.

• This feature can be implemented both in trucks and trailers

• No new product or protocol needs to be created for the implementation.

• Apart from that the feature will add value for customers and hence benefit the

business.

1.2 Why the final concept was selected over others?

ZigBee is a new technology

• Simple to implement,

• Less expensive

• Low power requirements over Bluetooth and WiFi

• Various Profiles for Home Automation, Health Care, Smart Energy have been

created in ZigBee but there is no dedicated profile for transportation/

automobiles.

• By slightly modification in the profiles, a custom profile can be easily created.

This saves a lot of ground work.

1.3 Project Validation and Status

Checked for handling the errors that might occur due to wrong UART

transmission.

• Over the air messages have been checked by Freescale Sniffer and were found to

be complying ZigBee protocol.

• The system involves interfacing ZigBee modules to TSD and Trailer Controller.

• The interface to TSD has be successfully implemented and thoroughly checked

for proper functioning.

• The system, however, has not been validated on an actual trailer and driver

cabin.

• The main limitation in implementing on trailer & driver cabin is interference

from the metal walls between them.

The product as defined in the scope is ready for implementation. It is

successfully able to display and control few parameters.

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2. ABOUT ZIGBEE

ZigBee is a worldwide open standard for wireless radio networks in the monitoring and

control fields. The standard was developed by the ZigBee Alliance (an association of

international companies) to meet the following principal needs:

low cost

ultra-low power consumption

use of unlicensed radio bands

cheap and easy installation

flexible and extendable networks

integrated intelligence for network set-up and message routing

Some of the above requirements are related - for example, the need for extremely low

power consumption is motivated by the use of battery-powered nodes which can be

installed cheaply and easily, without any power cabling, in difficult locations.

2.1 Application

Application areas that are suitable for ZigBee networks are likely to have the following

characteristics or requirements:

low data rates (less than 250kbps)

nodes which are idle (not transmitting/receiving) for long periods

node locations where cables would be difficult or expensive to install

a need to modify the network (add, remove or move nodes) while in service

The following are typical application areas in which ZigBee provides a low-cost solution

(this is not an exhaustive list):

Commercial Building and Home Automation: Electronic control within a

building or home can be implemented through wireless networks - example

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applications are HVAC (heating, ventilation and air-conditioning), lighting,

curtains/blinds, doors, locks and home entertainment systems.

Security: Another important application within commercial buildings and the

home is security – both intruder and fire detection.

Healthcare: This field employs sensors and diagnostic devices that can be

networked by means of a wireless network. Applications include monitoring

during healthcare programs such as fitness training, in addition to medical

applications such as patient monitoring.

Vehicle Monitoring: Vehicles usually contain many sensors and diagnostic

devices, and provide ideal applications for wireless networks. A prime example

is the use of pressure sensors in tyres, which cannot be connected by cables.

Agriculture: Wireless networks can help farmers monitor land and

environmental conditions in order to optimize their crop yields. Such networks

may require wide geographical coverage, but ZigBee addresses this issue by

offering network topologies that allow the relaying of messages from node to

node across the network.

2.2 Basic Software Architecture

ZigBee offers high-level functionality concerned with network structure, message

routing and security. This functionality is provided by the ZigBee software layer.

Figure 2: ZigBee Software Architecture

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This layer sits above another layer concerned with low-level network operation such as

addressing and message transmission/reception – this is referred to as the

Physical/Data Link level. The application is the highest level software, sitting above the

ZigBee layer.

The Physical/Data Link level is based on the IEEE 802.15.4 wireless network standard,

described below.

IEEE 802.15.4 Foundation

As indicated above, the ZigBee software sits on top of the Physical/Data Link level,

which is provided by the IEEE 802.15.4 standard. This standard brings many of the

fundamental principles of ZigBee networks, including:

Ultra-low power consumption

Use of unlicensed radio bands

Easy installation

Low cost

ZigBee builds on the IEEE 802.15.4 functionality by adding capabilities for more flexible

network topologies, intelligent message routing and enhanced security measures.

The Physical/Data Link level comprises two IEEE 802.15.4 layers:

MAC (Media Access Control) sub-layer – Layer concerned with the interface to

the physical transmission medium (radio, in this case). It exchanges data bits

with this medium, as well as exchanging data bits with the layer above.

PHY (Physical) layer – Layer responsible for addressing i) for outgoing data it

determines where the data is going; ii) for incoming data it determines where

the data has come from. It is also responsible for assembling data packets or

frames to be transmitted and for decomposing received frames.

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The Network Layer handles addressing and routing by invoking actions in the MAC

layer. Its tasks include:

Starting the network

Accessing the Network Address

Adding devices to and removing them from the network

Routing messages to their intended destinations

Applying security to outgoing messages

Implementing route discovery in Mesh Topologies and storing routing table

implementation

The ZDO Management Plane

This plane spans the APS and NWK, and allows the ZDO to communicate with these

layers when performing its internal tasks. It also allows the ZDO to deal with requests

from applications for network access and security functions using ZDP messages.

Application Support Sub-layer (APS)

The APS is responsible for communication with the relevant application for example,

when a message arrives to illuminate LED, the APS layer relays this information to the

responsible application using the endpoint information in the message. The message is

passed through the Service Access Point which exists between the APS layer and each

application (endpoint).

Application Objects

Up to 240 application are supported on a single ZigBee node. Each application object is

an endpoint and is numbered between 1 and 240. The ZigBee Device Objects (ZDO) has

number of initialization and communication roles.

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2.3 Reliability Measures offered by ZigBee

ZigBee offers a range of techniques to ensure reliable communications. These are

described below.

Listen Before Send

The transmission scheme used in ZigBee avoids transmitting data when there is activity

on the chosen channel – this is known as Carrier Sense, Multiple Access with Collision

Avoidance (CSMA-CA).

Put simply, this means that before beginning a transmission, a node listens on the

channel to check whether it is clear. If activity is detected on the channel, the node

delays the transmission for a random amount of time and listens again. If the channel is

now clear, the transmission can begin, otherwise the delay-and-listen cycle is repeated.

Acknowledgements

An acknowledgement mechanism is built into ZigBee to ensure that messages reach

their destinations.

When a message arrives at its destination, the receiving device sends an

acknowledgement to say the message has been received. If the sending device does not

receive an acknowledgement within a certain time interval, it resends the original

message (it can resend the message several times until the message has been

acknowledged).

Alternative Routes

In a Mesh topology, the network has built-in intelligence to ensure that messages reach

their destinations. If the default route to the destination node is down, due to a failed

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intermediate node or link, the network can “discover” and implement alternative routes

for message delivery.

2.4 Security Measures offered by ZigBee

ZigBee networks are highly secure. They incorporate measures to prevent intrusion

from potentially hostile parties and from neighboring ZigBee networks. To this end, a

“Security Toolbox” is included with ZigBee, offering the following features:

AES-based Encryption

A very high-security, key-based encryption system is used to prevent external agents

from interpreting ZigBee network data. Data is encrypted at the source and decrypted at

the destination using the same key - only devices with the correct key can decrypt the

encrypted data.

A 128-bit encryption system is employed based on the AES (Advanced Encryption

Standard) algorithm.

Message Timeout

This feature allows timed-out messages to be rejected, preventing message replay

attacks on the network.

A frame counter is added to a message, which helps a device determine how old a

received message is - the appended value is compared with a value stored in the device

(which is the frame counter value of the last message received). This value only

indicates the order of messages and does not contain time/date information. This

allows protection against replay attacks in which old messages are later re-sent to a

device.

An example of a replay attack would be a malicious individual recording the open

command for a garage door opener, and then later replaying it to gain entry to the

property.

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Access Control Lists

A provision of the underlying IEEE 802.15.4 standard is that a node is able to select the

other network nodes with which it is prepared to communicate. This is achieved using

an Access Control List (ACL), maintained in the device, which contains the MAC

addresses of nodes with which communication is allowed.

The source node of an incoming message is compared against this list, and the result is

passed to the higher layers which decide whether to accept or reject the message.

However, note that if messages are not encrypted, the alleged source of a message could

be falsified.

3. PRESENT TECHNOLOGY

At present the HMI on the Trailer displays the temperature of the Trailer. It also allows

changing the Set Temperature. In order to check the Trailer Temperature, the driver has

to see the Trailer HMI. In case any alarm occurs, the Trailer controller will display a

status light along with HMI displaying the alarm. Driver of the truck will recognize the

same by seeing this in the Rear View mirror. The driver needs to stop the vehicle and

need to walk to the end of the trailer to check HMI. And only after browsing through the

screens of HMI, he can recognize which alarm has occurred, the priority and the severity

of the Alarm decide the actions required. This entire process is inefficient as it

consumes time and can be inconvenient during rains and snowfall.

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4. PROJECT DESCRIPTION

The project involves 2 protocols of communication

UART Communication – to communicate to Trailer Microcontroller and to send

information to Truck Standard Display

Over the Air Transmission – to send the information from one ZigBee device to the

other ZigBee device

4.1 UART Communication

UART stands for Universal Asynchronous Receiver and Transmitter which translates data

between parallel and serial forms. UART is usually used in conjunction with

communication standards like RS232, RS422 or RS485.

The Universal Asynchronous Receiver/Transmitter (UART) takes bytes of data and

transmits the individual bits in a sequential fashion. At the destination, a second UART

re-assembles the bits into complete bytes. Each UART contains a shift register which is

the fundamental method of conversion between serial and parallel forms. Serial

transmission of digital information (bits) through a single wire or other medium is

much more cost effective than parallel transmission through multiple wires.

In our project we have two ZigBee devices; one in the trailer and the other in Driver’s

cabin. These devices talk to the Controller in Trailer and TSD (Truck Standard Display)

in Driver cabin through UART.

The commands are wrapped in DATAPAC protocol and it is in this format they are

received and issued to get the response from the Controller and TSD. TSD is

programmed to understand this protocol. The commands sent from TSD are processed

in the Cabin ZigBee Device and decoded to understand which command has been

issued. Upon completion of this step the ZigBee Device then sends over the air messages

or requests at 25O kbps which is received by the trailer ZigBee Device.

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In the trailer ZigBee Device a 13 second timer updates Alarms and Return Air

temperature in two respective variables. These variables are accessed and the value in

them is sent over the air when a request is acknowledged from Cabin ZigBee device by

trailer ZigBee device.

In the case of Clear Individual Alarms and set Set Point temperature alarm and Set Point

value is sent over the air along with a request. Upon successful acknowledgement by

Trailer ZigBee device the Alarm is cleared or the Set point temperature is set to the

specified value in the TSD.

4.1.1 UART communication on controller side:

The controller board is SR3 board and it has a serial port employing RS232 standard.

The ZigBee device has UART pins through which can receive data. The ZigBee board

works on CMOS logic 3.3V and RS232 standard generated voltages between -12V to

12V. In order to handshake these two standards we employ an IC called MAX3232

which converts CMOS logic to RS232 standard.

Once this interface is ready when the ZigBee device sends the commands in DATAPAC

protocol (standard employed in SR3 board and TSD (Cabin HMI) ) at the default baud

rate of 1200 the controller will reply back with information as requested by the specific

command sent from ZigBee device. This information is then processed and sent over the

Figure3: MAX 3232 IC

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air to the ZigBee device in the Driver Cabin. The two commands used are GDT (Global

Data Table) read and Alarm Queue read.

4.1.2 UART communication on TSD side

The ZigBee device in cabin now has the temperature and Alarm information which

when requested by the TSD is sent to the TSD through UART. For this purpose the TSD

sends the commands to ZigBee device and it is programmed such that it can reply back

with the data it now has packaged in DATAPAC format for TSD to understand and

display for the Driver to view.

So far we are using SR3 communicator tool, a user interface tool which simulates TSD.

Here we use UART integrated virtual com port for communication between PC and

ZigBee device.

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4.1.3 UART Messages and Commands

DATAPAC commands used in the Cabin & Trailer Device

For Reading Temperature: Return Air Temperature: 0x16, 0x16, 0x56, 0x01, 0xBD, 0x00, 0x00, 0x00, 0x00,

0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x63, 0x51

Return Air Temperature Read Response: 0x16, 0x16, 0xD6, 0x01, 0xBD, Value low, Value high, 0x84, 0x31, 0x50, 0x52, 0x52, 0x41, 0x20, 0x00, 0x00, 0x00, CRC, CRC

For Reading Alarms Queue: 0x16, 0x16, 0x41, 0x01, 0x00, 0x00, 0x00, 0x3D, 0xF3

Alarm Read Response: 0x16, 0x16, 0xC1, 0x01, 0x00, 0x0D, 0x00, 0x04, 0x0D, 0x0A, 0xFF, 0x84, 0x01, 0x5C, 0x00, 0x81, 0x01, 0x2A, 0xFF, 0x81, 0x05, 0x25, 0xFF, 0x84, 0x05, 0x05, 0xFF, 0x82, 0x01, 0x03, 0x00, 0x82, 0x41, 0x04, 0x00, 0x82, 0x41, 0xCB, 0x00, 0x82, 0x41, 0xCC, 0x00, 0x82, 0x41, 0x0C, 0x00, 0x84, 0x01, 0x02, 0x00, 0x82, 0x01, 0x06, 0xFF, 0x84, 0x01, 0x34, 0x00 , 0x82, 0x11, 0xD0, 0x30

For Writing Temperature GDT:

Set Point Temperature: 0x16, 0x16, 0x36, 0x07, 0x02, value lo, value hi, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, CRC, CRC

Set Point Temperature Write Response: 0x16, 0x16, 0xB6, 0x07, 0x02, value low, value high, 0x4C, 0x3B, 0x53, 0x45, 0x54, 0x50, 0x54, 0x01, 0x00, 0x00, CRC, CRC

LEGEND

Commands Send by TSD to ZigBee device (or Controller)

Response Send by ZigBee device (or Controller) to TSD

CRC Bytes

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For Clearing Alarms:

0x16, 0x16, 0x52, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0xC0, 0xF9

Clear Alarm Response: 0x16, 0x16, 0xD2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x98, 0xE1

4.2 Over the Air Transmission

The data obtained from the Micro Controller follows DATAPAC protocol which has its

own header, footer, payload and other auxiliary information. So in order to send the

required parameters i.e. Temperature and Alarm, they need to be extracted from the

data response obtained from the Microcontroller. So the ZigBee device interfaced to

Micro Controller extracts the necessary data and stores it in a buffer in its memory.

In order to successfully communicate to the other ZigBee device, this device has to

follow the ZigBee protocol and transmit the data Over the Air. The ZigBee protocol has

its own various Headers, Footer and Payload information. It becomes the task of the

device to formulate a command, which follows the protocol, uses the data obtained

earlier as a payload, and appends required Header information. This command is

encrypted and transmitted over the air.

The other ZigBee device sitting in the Driver Cabin always senses for information from

the air medium. So as soon as it receives information that follows ZigBee protocol, it

stores the command in its buffer. Then it processes (decrypts) the command to extract

the payload and store the information in its memory. This information becomes

Payload for the command that will be sent to the Truck Standard Display, which again

follows the DATAPAC protocol.

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Over the Air Messages

Read Return Air

61 88 30 11 11 00 00 6F 79 48 00 00 00 6F 79 0A 15 00 08 02 04 04 01 08 B8 00 53 00 04 00 00 00

Read Return Air response

61 88 BA 11 11 6F 79 00 00 48 00 6F 79 00 00 0A 14 00 08 02 04 04 01 08 1E 18 53 01 04 00 00 29 00 F0 00 00

Write Set Point

61 88 88 11 11 00 00 6F 79 48 00 00 00 6F 79 0A 16 00 08 02 04 04 01 08 7E 00 52 02 05 00 29 04 12 00 00

Write Set Point Response

61 88 97 11 11 6F 79 00 00 48 00 6F 79 00 00 0A 16 00 08 02 04 04 01 08 7C 18 52 04 00 04 12 00 00

Read Alarm

61 88 0B 11 11 00 00 6F 79 48 00 00 00 6F 79 0A 11 00 08 00 00 04 01 08 11 10 00 00 13 00 00 00

LEGEND:

MAC Header NWK Header

APS Header ZCL Header

ZCL Payload MAC Footer

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Read Alarm Response

61 88 94 11 11 6F 79 00 00 48 00 6F 79 00 00 0A 13 00 08 00 00 04 01 08 C1 18 00 01 13 00 00 20 16 16 C1 01 00 0D 00 04 0D 0A FF 84 01 05 FF 82 01 03 00 82 41 04 00 82 41 CB 00 82 41 CC 00 82 41 5C 00 81 01 2A FF 81 05 0C 00 84 01 25 FF 84 05 02 00 82 01 06 FF 84 01 34 00 82 11 D0 30 00 00

Clear Alarm

61 88 88 11 11 00 00 6F 79 48 00 00 00 6F 79 0A 16 00 08 02 04 04 01 08 7E 10 00 02 13 00 00 00 00 00

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4.3 Project Software Architecture

The design of the embedded software code in the project can be understood from the

FFD (Functional Flow Diagram) and User Case Diagram.

FFD

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User Case Diagram

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4.4 Description of the Set Up

In the current set up there are two ZigBee devices one in the Driver’s Cabin and other in Trailer. Let us name the ZigBee device in Cabin as Device 1 and the ZigBee device in the trailer as Device 2.

Device 1 is interfaced with the TSD and Device 2 with SR2 or SR3 controller board in Trailer. The SR2/ SR3 board is interfaced with various sensors through which various parameters like Return Air temperature, Set Point temperature, Discharge Air temperature; Alarms etc. are relayed and controlled.

We aim to display Return Air temperature and Alarm queue raised on TSD. Any number of alarms can be raised. The current POC is designed to handle 0 to 15 Alarms. We also control the Set Point temperature from the TSD and enable the TSD to clear individual alarms.

As mentioned previously the commands and replies from the Controller are in the DATAPAC protocol format.

Device 1 in Cabin is the router and Device 2 in Trailer is the coordinator. As soon as the two devices are turned on the Device 2 forms a network and Device 1 joins it. Then the Device 1 then sends a binding request to the coordinator which it acknowledges back and thus the two devices get bonded to each other and are ready for over the air communication.

Device 1 is interfaced with TSD through UART pins. After 10 seconds the TSD is programmed to issue one command after another. The commands are for reading the Return Air temperature, Write Set Point temperature and read Alarms Queue. Hence each command is sent after 30 sec cycle. The Set Point is set in the TSD through button press. Return Air cannot be changed and hence is only read commands for it are generated from TSD.

Whenever a command is issued the ZigBee Device 1 processes it and based on the Byte 3 of the sequence it determines which command is issued. This part is handled through the IR_ReadCommandFromTSD function in the Cabin ZigBee device. Based on Byte 3 now various functions are called which are IR_ReadTemperatureRequest, IR_ReadAlarmRequest and IR_WriteAttribute as shown in the Functional Flow Diagram.

These functions then send over the air request for read or write parameters which is then received and acknowledged by the Device 1 in the trailer. In case of Return Air temperature read and Alarm Queue Read just a request is generated, different for both. On reception of this request on the other end, the value/status of the Return Air temperature or Alarms is read respectively from the two variables on Device 2. Variable for Return Air temperature is a 16 bit unsigned integer and for Alarms Queue is an array of size 64. The value/information in them is then sent over the air to Device 1 in Cabin which are then displayed on the TSD as soon they are received along with the success acknowledgement.

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The two variables are updated by through a 20 Second timer which generates commands in the DATAPAC format to read the Return Air temperature and Alarms Queue from the Controller ( SR2/SR3).

In the Set Point write the value fed in the TSD through button press is sent over the air to Device 2 to be written through the controller. Similar is the case with individual Alarm Clear.

Figure4: Freescale MC1322x Network Node

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5. HARDWARE AND SOFTWARE TOOLS USED

We have used the following hardware in our project.

5.1 Hardware

Freescale ZigBee Network Node based on ARM7 TDI processor with MC1322V

Micro Controller Unit (MCU)

Freescale ZigBee Sensor Node based on ARM7 TDI processor with MC1322V

MCU

Freescale ZigBee Low Power Node based on ARM7 TDI processor with MC1322V

MCU

CEL developed ZigBee Evaluation Board based on ARM 7 processor employing

MC13324V controller.

MAX3232 CMOS logic to RS232 converter

IAR JLink POD

SR3 Microcontroller installed in ThermoKing Trailer

Oscilloscope

Description of ZigBee Evaluation Boards:

5.1.1 Freescale ZigBee Network Node: It has the capability to

be all the possible three types of node

viz: Coordinator, Router and End

Device. The 1322x Network Node (NN)

is an IEEE 802.15.4 compliant

evaluation board based on the

Freescale MC1322x device. The heart of

the 1322x Network Node is Freescale’s

MC1322x 99-pin LGA Platform-in-

Package (PiP) solution that can be used

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for wireless applications ranging from simple proprietary point-to-point connectivity to

complete ZigBee mesh networking. The MC1322x is designed to provide a highly

integrated, total solution, with premier processing capabilities and very low power

consumption. The 1322x Network Node provides a platform to evaluate the MC1322x

device, develop software and applications, and demonstrate IEEE 802.15.4 and ZigBee

networking capabilities. The Network Node surrounds the core device with capabilities

that provide a complete 802.15.4 radio, user interface, debugging capabilities,

connection to personal computers (PCs) and other devices, and portability.

5.1.2 Freescale ZigBee Sensor Node:

The 1322x Sensor Node is an IEEE 802.15.4 compliant evaluation board based on the

Freescale MC1322X device. The heart of the 1322x Sensor Node is Freescale’s MC1322x

99-pin LGA Platform-in-Package (PiP)

solution that can be used for wireless

applications ranging from simple

proprietary point-to-point connectivity to

complete ZigBee mesh networking. The

MC1322x is designed to provide a highly

integrated, total solution, with premier

processing capabilities and very low power consumption. The 1322x Sensor Node

provides a platform to evaluate the MC1322x device, develop software and applications,

and demonstrate IEEE 802.15.4 and ZigBee networking capabilities. The Sensor Node

surrounds the core device with capabilities that provide a complete 802.15.4 radio, user

interface, debugging capabilities, connection to personal computers (PCs) and other

devices, sensors, and portability.

5.1.3 Freescale ZigBee Network Node:

The 1322x-LPN is an IEEE 802.15.4 compliant wireless node based on the Freescale

MC1322x device. The heart of the 1322x-LPN

is Freescale’s MC1322x 99-pin LGA Platform-

in-Package (PiP) solution that can be used for

wireless applications ranging from simple

proprietary point-to-point connectivity to

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complete ZigBee mesh networking. The MC1322x is designed to provide a highly

integrated, total solution, with premier processing capabilities and very low power

consumption. The 1322x-LPN provides a platform to evaluate the MC1322x device,

develop software and applications, demonstrate IEEE 802.15.4 and ZigBee networking

capabilities and implement low power operation. The small form factor illustrates a

small footprint, 2-layer printed circuit board (PCB) layout with integrated printed-wire

F-antenna. The LPB provides a GPIO connector to interface with application devices, a

separate second unbuffered UART connector, and a full JTAG debug port connector.

5.2 Softwares Used

Freescale Beekit Graphical User Interface

IAR Embedded Workbench 5.0 IDE

SR2/SR3 communicator UI

Docklight

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6. CONCLUSION

So far we have achieved the primary objective to display the temperature and alarm

notification. The trailer device generates temperature and alarm parameters internally.

It passes the parameters over the air. The Cabin device receives the parameters, frames

the parameters as per the DATAPAC protocol. It sends it to Truck Standard Display via

UART.

From here on, we’ll be working on

• To interface the Trailer device to the Trailer Microcontroller, receive the data via

UART

• Besides just displaying the parameters in the driver cabin, this wireless

technology can also be used to allow the driver to control these parameters from

the Cabin itself. With this feature, the driver will not only be able to see the alarm

but can clear the alarm as well.

• This project using ZigBee devices can be used to allow the driver to control the

refrigerator parameters and other parameters like air discharge rate, air inflow

rate, pressure, humidity, pre-sets etc. from his cabin.

• Existing system in trucks can be made wireless too giving them all the

advantages of a wireless system.

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7. FUTURE IMPROVEMENT IN THE PROJECT

In the proposed project, the ZigBee network established will only transmit Current

Temperature and Alarms from Trailer Controller to the TSD. The same concept can be

extended to transmitting other necessary parameters to the Driver Cabin like air

discharge rate, air inflow rate, pressure, humidity, presets etc.

Also existing system in trucks can be made wireless too giving them all the advantages

of a wireless system.

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8. REFERENCES

The following are the references we used for the report.

1. The Freescale website and Technical Support

2. ZigBee Alliance Documents

3. ZigBee Specification 2007

4. BeeStack Application Development Guide for ZigBee 2007

5. BeeStack Software Reference Manual for ZigBee 2007

6. Reference Manuals for Development Boards

7. Freescale Wireless Connectivity Toolkit User’s Guide

8. Freescale Platform Reference Manual for ZigBee 2007

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