wireless system of actuation and supervision in pneumatic
ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
WIRELESS SYSTEM OF ACTUATION AND SUPERVISION IN
PNEUMATIC ACTUATORS THROUGH ZIGBEE PROTOCOL AND
ARDUINO
Adauto Granja
Marcelo Henrique de Almeida Orlandin
Lucas Emanuel Soeira
Universidade Paulista UNIP – Av: Carlos Consoni, 10 – Jardim Canadá – Ribeirão Preto - SP
[email protected]
[email protected]
[email protected]
Abstract. This paper presents an actuation and supervision system of pneumatic actuators through ZigBee protocol
that enables wireless communication by radiofrequency between these actuators and the microcontroller Arduino. The
graphical interface of actuation and supervision is programed in Visual Basic Language, and is responsible for
sending commands via serial port to a module called ZigBee Coordinator. This module transmits the information to the
Arduino, and monitors the sensor connected to it via ZigBee modules called end devices. Arduino receives information
from the ZigBee coordinator, interpreting them according to its program, developed in its platform, and acting on the
actuators and other instruments that may be incorporated into the system, such as sensors and transmitters. Twentyfour volt digital sensors with three wires, containing 50-mm optical sensitivity and 5-mm capacitive sensitivity, are
used. The use of wireless communication was opted along with Arduino because of various advantages offered by this
system, such as: economy of signal cabling, ease of maintenance and energy savings. Besides these factors, it is
important to emphasize that this system operates on an open platform, allowing the creation of low-cost sensor
devices, thus providing a wide variety of instruments connected to the same network.
Keywords: Arduino, ZigBee, Pneumatic actuators, supervision, radiofrequency
1. INTRODUCTION
The increasing need for efficient and autonomous systems, coupled with the advancing technologies of control and
communication solutions, makes low cost microcontroller accessibility and network trustworthiness necessary. This
tendency is increasingly more common in automated systems applications (Severino, 2008).
In this scenario, wireless network communication is growing rapidly due to the advantages offered by them, such as
economy of signal cabling, low cost installation, and ease in planning and installation (Lee et al., 2007).
Within this technology of wireless communication, there is ZigBee protocol, from ZigBee Alliance. ZigBee, which
is still under development, is based on IEEE 802.15.4 standard protocol, and allows operation in the following
frequency bands: 2.4 GHz, 915 MHz and 868 MHz. These are free and do not require a license for users, which is
making ZigBee a comprehensive global protocol.
Observing this tendency, this work aims to integrate this protocol into the Arduino microcontroller, through a
supervision system, and operates the electronic actuators. Every process can be followed in a graphical user interface
developed using Visual Basic, which will display status information from the sensors and buttons to drive the operating
process.
The Visual Basic program is responsible for sending commands, via serial port, to a module called ZigBee
coordinator. This module transmits the information to Arduino, and monitors the sensor connected to it, via ZigBee
modules called end devices. Arduino receives information from the ZigBee coordinator, interpreting them according to
its program, developed in its platform, and acting on actuators.
2. MATERIALS AND METHODS
2.1 Arduino
The electronic board, called Arduino, was created in 2005 by a team of Italians with the intention to create a micro
controller with open source hardware and software, and that was affordable to the majority of people (Arduino, 2013a).
Because it is an open platform, Arduino brings a great advantage to users: a commitment that volunteers take to
work to improve software and hardware. In addition, there is interaction between several companies that are selling kits
for Arduino (Info. Brazil, 2009).
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Thus, this work platform has grown a lot since its creation, becoming applicable to various types of situations. The
Modelix Company, a manufacturer of robotic kits, has been incorporating this control board into its products, such as
application control lift (Leomar, 2013). Other examples of applications are haptic glove (Pfleger, 2012.) robotic arms,
speed meter (Nunez, 2012).
The Arduino board is able to work in various types of automation that is necessary to program outputs according to
the variation of the input signals. Importantly, this adapter also works with communication protocols such as Bluetooth,
Internet, ZigBee and Modbus. Figure 1 illustrates an Arduino Mega 2560 plate.
Figure 1 – Arduino ATMega 2560 board
2.1.1
Arduino’s Hardware
The first board created by Arduino's team was Arduino Uno, but over the years, this model has undergone many
changes, and today Arduino has several different models: Arduino Due, Arduino Explore, Arduino Mega ADK,
Arduino BT (Arduino, 2013b).
Table 1 compares some of the microprocessors that compose an Arduino board and its properties (ATmega, 2006).
16 bits de
Micro processor FLASH
EEPROM
RAM
I/O
resolution
Serial UARTs
Channel ADC
Atmega640
64KB
4KB
8KB
86
12
4
16
ATmega1280
128KB
4KB
8KB
86
12
4
16
Atmega1281
128KB
4KB
8KB
54
6
2
8
Atmega2560
256KB
4KB
8KB
86
12
4
16
Atmega2561
256KB
4KB
8KB
54
6
2
8
Table 1 – Arduino board and its properties
The signboard used in this work will be the Arduino Mega, with a microprocessor based on ATmega 2560. It has 54
digital input / output pins, 16 analog inputs, 4 UARTs (hardware serial ports), a crystal oscillator of 16 MHz, a USB
connection, an input power, an ICSP connection, and a reset button (Arduino, 2013c).
2.1.2
Arduino’s Software
The developmental environment is a multiplatform application, developed in Java, with an open source code, which
runs on Windows, Linux and Mac (Werneck, 2009). Thanks to the input by multiple users, libraries with more functions
are being incorporated into the software, which makes development projects more dynamic and broad.
The function of this IDE is beyond providing a simple programming environment; it compiles the code and
downloads this file into the microcontroller via a USB cable. Besides being a programming environment and compiler,
it also has a communication box able to send and receive serial information. Figure 2 portrays the variable process
declaration; it also illustrates how output driving is made from a serial port reading. (Gibb, 2010).
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Figure 2 – Arduino IDE
2.1.3
Arduino Shields
Several different manufacturers make the shields for Arduino boards, whose service is to add extra functions to the
Arduino. Examples: Ethernet, ZigBee, Bluetooth, Wi-Fi, EasyVr, among others (Labdegaragem, 2013). The study of
ZigBee shield will be specified here, which will be the subject of study in this work. Figure 3 illustrates an Arduino
board coupled to three shields, the last one being, ZigBee.
Figure 3 – Arduino board coupled to three shields
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
2.2 Zigbee Protocol
ZigBee is a communication protocol based on wireless technology that has been developed and perfected by Xbee
Alliance. An alliance with large automation companies: Phillips, Schneider Electric, Texas Instruments, Legrand,
among others (Zigbee, 2013a).
The ZigBee standard is based on IEEE 802.15.4 protocol and operates in the global 2.4 GHz frequency. It can also
operate on frequencies of 915 Mhz in the Americas and 868 MHz in Europe. A great advantage it has in relation to
other wireless technologies is that it is not necessary to acquire a license to use it.
Only ten years on the market, the ZigBee standard today is widely used in building and residential automation.
Although it has many advantages, this protocol is still debilitated as to the amount of data that can be transmitted
through it, compared to other protocols already established in the industry, such as Fieldbus and Profibus (Lopes, 2012).
Compared to these same protocols, ZigBee has the following advantages: low energy consumption, reduction of
electromagnetic interference (since it is not necessary to use cabling), and the possibility to connect a much larger
amount of equipment on the same network.
According to ZigBee Alliance, over 600 certified products currently use the ZigBee standard (Zigbee, 2013b). In
order to develop this project, XBee radio frequency (RF) modules are used.
2.2.1
RF Xbee Module
The RF XBee module is currently manufactured by Digi and designed to meet the IEEE 802.15.4 standard,
operating in the global frequency of 2.4 GHz (Xbee, 2013a). The RF XBee modules also come with digital inputs and
outputs, analog inputs and PWM outputs (Xbee, 2013b). These inputs and outputs can be individually accessed through
specific commands, called AT Commands.
Table 2 shows the general characteristics of the module used in this work. Table 3 shows the pin functions of the
module. Figure 4 shows a dimensional drawing of the module. Figure 5 illustrates the structure of AT Commands
(Xbee, 2013c).
Figure 4 – X-bee Mechanical Drawing
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Specification
Performance
Indoor/Urban range
Outdoor RF line-of-sight Range
Transmit Power Output (software selectable)
RF data rate
Serial Interface Data Rate
Receiver Sensitivity
Power Requirements
Supply Voltage
Transmit Current (typical)
Idle/Receive Current
Power-down Current
General
Operating Frequency
Dimensions
Operating Temperature
Antenna Options
Part I - International Congress
Section VI - Hydraulics & Pneumatics
XBee
Up to 100 ft (30m)
Up to 300 ft (90m)
1mW (0 dBm)
250Kbps
1200bps - 250Kbps (non-standard baud rates also
supported
-92 dBm (1% packet error rate)
2.8V - 3.4V
45mA (@3.3V)
50mA (@3.3V)
<10µA
ISM 2.4Ghz
0.960" x 1.087" (2.438cm x 2.761cm)
-40 to 85° C (Industrial)
Integrated Whip Antenna, Embedded PCB
Antenna U.FL Connector, RPSMA connector
Networking & Security
Supported Network Topologies
Number of Channels
(Software selectable)
Addressing Options
Agency Approvals
United States (FCC Part 15.247)
Industry Canada (IC)
Europe (CE)
Japan
Australia
Point-to-point, Point-to-multipoint & Peer-topeer
16 Direct Sequence Channels
PAN ID, Channel and Addresses
OUR-XBEE
4214A XBEE
ETSI
R201WW07215214
C-Tick
Table 2 - General characteristics of the module
Table 3 – Pin Assignments for the Xbee and Xbee-PRO Modules
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Figure 5 - Structure of AT Commands
Another way to make communication is through direct access to the module pins that are on the network. Thus, digital
or analog output of a module is directly related to the input of another one. This is the approach used in this work.
The Xbee programmer is used to configure the network that communicates serially with the computer. This programmer
sends AT commands through a program called X-CTU to the modules, configuring them. Table 4 illustrates the AT
commands used for the creation of the network.
AT Commands
+++
Enables programming
Defines an ID for modules network communication
(PAN ID). All modules of the network must have the
same one.
ATID
PAN ID
ATMY
My Address
ATDn
I/O pin configuration
Sets the module address on the network
Defines the settings of I/O pins. “n” is the number of
digital input or output.
ATIA
I/O input address
Defines the address of the transmitter module.
ATDL
Destination address low
Defines the address of the receiver module.
ATIR
Sample Rate
ATPR
Pull-up-Resistors
Sets the monitoring frequency of digital gates.
Disables internal pull up resistors of digital input pins.
ATWR
Write
Saves changed settings
Table 4 - AT commands and their definitions
Two modules are used for communication: transmitter and receiver. Table 5 shows settings of the transmitter module.
Table 6 portrays receiver settings.
Radio Transmitter
Reset
PAN ID
MY Address
ATRE N/A
ATDID 3001
resets the radio to its factory settings
any address from 0 to FFFE will do
ATMY 1
Destination address high
ATDH 0
indicates a 16-bit address
Destination address low
ATDL 2
the address of the receiving radio
PIN 0 I/O configuration
ATD0 3
ATPR 0
digital input
20ms, 14 in hexadecimal = 20 in
decimal
disables internal pull-up resistor on
all pins
ATWR N/A
saves the settings to flash memory
Sample rate
Pull-up resistors
Write to memory
ATIR 14
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Table 5 - Transmitter Module Settings
Radio Receptor
Reset
ATRE N/A
resets the radio to its factory settings
PAN ID
ATID 3001
any address from 0 to FFFE will do
MY Address
ATMY 2
Pin 0 I/O configuration
ATD0 5
digital output, HIGH on startup
I/O Input Address
ATIA 1
address of the transmitting radio
Write to Memory
ATWR N/A
saves the settings to flash memory
Table 6 - Receiver module settings
Figure 6 illustrates electronic diagram transmission signal, which is triggered by a digital output from Arduino. Figure 7
shows a diagram of signal receiving.
Figure 6 - Diagram of a sending signal from a Xbee Module
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Figure 7 - Sensor signal reception
2.3 Visual Basic
Visual Basic is a programming language developed by the Microsoft Company, initially designed to start people in
programming. At first, the language was simpler, named only Basic, but a succession of changes and improvements
made this language become Visual Basic, as we know it today (Roman et al., 2002; Cornel and Morrison, 2002).
Visual Basic is a tool for object-oriented programming that allows the creation of graphical user interfaces, database
access, serial communication, etc. Visual Basic was chosen as the platform for this work because it has simple
programming language, a dynamic graphical interface, and has features that facilitate communication through the serial
port between the program developed and Arduino.
2.4 Simulation
This work will drive two pneumatic cylinders that simulate the rejection, or not, of a piece according to its size. The
system rejection, which due to the didactical plant of the Festo Company, provided by the Paulista University, not using
a treadmill, will be tested on a workbench. A support for the inductive sensor is manually placed so that the piece will
pass through it. If the piece is the right size, nothing happens. However, if the piece triggers the sensor, this will initiate
a pre-programmed sequence of activation in pneumatic cylinders located in the Festo plant. Figure 8 shows pneumatic
diagram of the system. Figure 9 illustrates electronic actuation diagram of the valves. Figures 10 is a portrait of the
pneumatic circuit mounted on the lab at Paulista University.
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Figure 8 – Pneumatic Diagram
Figure 9
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Figure 10 – Pneumatic Plant
3. RESULTS
For purposes of tests, 200 consecutive activations were conducted under the following conditions:
First condition: Less than ninety meters without physical barriers or signs of other frequencies.
Second condition: Less than ninety meters without physical barriers but with signals from other frequencies
(frequency up to 1 MHz).
Third condition: More than ninety meters without physical barriers or signs of other frequencies.
Results:
First condition: the system presented an efficiency around 95%
Second condition: Even with signs of other frequencies, the system showed the same performance
Third condition: The system displays unsatisfactory performance
Observed during the workbench test of this system a satisfactory answer was shown as to ease programming and
configuration of hardware and software involved. With regard to the response time of the commands, the system met
expectations. The software used to develop the interface was efficient in sending commands, however, demonstrated
limitations in the supervision.
4. CONCLUSION
XBee communication modules demonstrate some advantages, such as ease of installation and implementation,
saving cabling and low power consumption of the RF modules. Allied to these advantages are the ease of programming,
the large number of analog and digital inputs and outputs and variety of devices with which Arduino can work, make
this system able to deploy in various types of application.
The software used to develop the GUI, although it worked, showed limitations in supervision, due to not being
suitable for the development of supervisor interfaces. Thus, in future applications the use of a specific software
development supervisor is suggested; such as Indusoft, iFix and ellipse because these, like the Arduino, have modbus
communication drivers.
5. ACKNOWLEDGEMENTS
This project is supported by Paulista University.
6. REFERENCES
Arduino, 27 May. 2013a <http://arduino.cc/en/>
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ABCM Symposium Series in Mechatronics - Vol. 6
Copyright © 2014 by ABCM
Part I - International Congress
Section VI - Hydraulics & Pneumatics
Arduino, 27 May. 2013b <http://arduino.cc/en/Main/Products?from=Main.Hardware>
Arduino, 27 May. 2013c < http://arduino.cc/en/Main/ArduinoBoardMega2560>
ATmega, Microcontroller with 640/1280/1281/2560/2561 Bytes In-System Programmable Flash, 2006
Cornell, Gary. and Morrison, Jonathan., 2002. “Programming VB.NET: A guide for Experienced Programmers”
Gibb, Alícia M. 2010. “New Media Art, Design, and the Arduino Microcontroller: A malleable tool”. Feb. 2010
Info. abril, 2009. “O hardware em código aberto”. 9 Mar. 2009
<http://info.abril.com.br/professional/tendencias/hardware-livre-leve-e-solto.shtml>
Labdegaragem, 27 May. 2013
<http://www.labdegaragem.org/loja/index.php/catalogsearch/result/?q=shield+arduino&x=-1115&y=-193>
Lee, J.S., Su, Y.W., Shen, C.C., 2007. A comparative Study of Wireless Protocols: Bluetooth, UWB, ZigBee and Wi-fi
Leomar, 27 May. 2013
<http://www.leomar.com.br/modelix/index.php?option=com_content&view=article&id=278%3A2108-2009&catid=101%3Atv-modelix&Itemid=126&lang=pt >
Lopes, A.P., Nascimento, D.B., Lima, M.M.L. S., 2012. “Projeto de aplicação zigbee em rede de automação industrial”.
Pfleger, S.G., 2012. “Plataforma Robótica Genérica Baseada em Arduino”. 03 Mar. 2012
<http://www.das.ufsc.br/~raffo/SeminariosRobotica_DAS/11.Seminario_22.03.2012_S.G.Pfleger/Arduino%20e%2
0aplicacoes.pdf>.
Nunez, A.F., 2012. “Uma introdução ao Arduino e suas aplicações na robótica”. 29 May. 2012
<http://pet.inf.ufpel.edu.br/sacomp/2012/palestras/SACOMP2012-29_05-4.Arduino.pdf>.
Roman, S., Petrusha, R., Lomax, P., 2002. “VB.Net Language, In a Nutshell . A desktop quick reference”.
Severino, R.A.R.S., 2008. On the use of 802.15.4/ZigBee for Time-Sensitive Wireless Sensor Network Application,
Instituo Superior de engenharia do porto, Oct. 2008
Werneck, P., 2009. “Introdução ao Arduino”. 22 Jun.. 2009 < http://www.sabereletronica.com.br/secoes/leitura/1307>
Xbee, Product Manual, 13 Feb. 2013a “v1.xEx - 802.15.4 Protocol For RF Module Part Numbers: XB24-A...-001,
XBP24-A...-001” pg.05
Xbee, Product Manual, 13 Feb. 2013b “v1.xEx - 802.15.4 Protocol For RF Module Part Numbers: XB24-A...-001,
XBP24-A...-001” pg. 7
Xbee, Product Manual, 13 Feb. 2013c “v1.xEx - 802.15.4 Protocol For RF Module Part Numbers: XB24-A...-001,
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Zigbee, 27 May. 2013a <www.zigbee.org/About/OurMembers.aspx>
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7. RESPONSIBILITY NOTICE
The authors are the only responsible for the printed material included in this paper.
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