On the Design of a Bluetooth Data Acquisition Card for the

On the Design of a Bluetooth Data Acquisition Card for the

On the Design of a Bluetooth Data Acquisition Card for the Control
of Manipulator Robots
A. Donado, J. Castañeda-Camacho F. Reyes, G. Mino and G. Muñoz-Hernández.
Facultad de Electrónica de la Benemérita Universidad Autónoma de Puebla.
Puebla, Puebla, 72000, México.

ABSTRACT
A simple and successful design of a Bluetooth data acquisition
card for the control of manipulator robots is presented. The
integration of software through a program in Visual C#
language and the use of a microcontroller PIC18F4550
embedded with a bluetooth module, give rise to a wireless data
acquisition card with digital and analog inputs and outputs.
This embedded system is applied to the control of a
manipulator robot with three degrees of freedom.
Keywords: Data acquisition card, manipulator robots and
bluetooth.
1. INTRODUCTION
Bluetooth wireless communication is a wireless LAN
technology designed to operate in an environment of many
users to connect devices with different functions such as
telephones, computers, cameras, printers, etc [1]. A Bluetooth
LAN is an ad hoc network that is formed spontaneously and
provides support for three general application areas using short
rage wireless connectivity.
Data and voice access points. Bluetooth facilitates real-time
voice and data transmissions by providing effortless wireless
connection of portable and stationary communications devices.
Cable replacement. Bluetooth eliminates the need for
numerous, often proprietary, cable attachments for connection
of practically and kind of communication device. Connections
are instant and are maintained even when devices are not
within line of sight. The range of each radio is approximately
10 m, but can be extended to 100 m with an optional amplifier.
Ad hoc networking. A device equipped with a Bluetooth
radio can establish instant connection to another Bluetooth
radio as soon as it comes into range.
The Bluetooth technology regulated by the protocol IEEE
802.15 is defined as a layered protocol architecture consisting
of core protocols, cable replacement and telephony control
protocols, and adopted protocols [1, 2]. The Bluetooth core
protocols form a five-layer stack consisting of the following
elements as it is shown in Fig. 1.
The authors would like to thank the PROMEP project 103.5/08/3343 and
anonymous reviewers for their valuable comments and suggestions that
enhanced the quality of this work.
Fig. 1. Bluetooth Stack
Radio. Specifies details of the air interface, including
frequency, the use of frequency hopping, modulation scheme,
and transmit power.
Baseband. Concerned with connection establishment within a
piconet, addressing, packet format, timing and power control.
Link manager protocol (LMP). Responsible for link setup
between Bluetooth devices and ongoing link management.
This includes security aspects such as authentication and
encryption, plus the control and negotiation of baseband
packet sizes.
Logical link control and adaptation protocol (L2CAP).
Adapts upper-layer protocols to the baseband layer. L2CAP
provides both connectionless and connection-oriented services.
Service discovery protocol (SDP). Device information,
services and the characteristics of the services can be queried
to enable the establishment of a connection between two or
more Bluetooth devices.
RFCOMM is the cable replacement protocol included in the
Bluetooth specification. RFCOMM provides binary data
transport and emulates EIA-232 control signals over the
Bluetooth baseband layer. EIA-232 (formerly known as RS232) is a widely used serial port interface standard.
In this work we design of a Bluetooth data acquisition card for
the control of manipulator robots, concentrating on the
RFCOMM protocol which is a radio frequency emulator
oriented to a computer COM port, and the AT commands
which are used for configuring Bluetooth devices [1- 3].
2. DESIGN OF DATA ACQUISITION CARD (DAQ)
The data acquisition card is designed through the module Parani
ESD 1000 with 8 digital inputs, 8 digital outputs, 6 analog inputs
and 2 analog outputs for pulse-width modulation (PWM). This
includes USB interface, Bluetooth interface and dedicated lines for
USB PIC boot loader, in circuit serial programming (ISCP).
As we can see in Fig. 2, the core of the card is the PIC18F4550
microcontroller [4-6].
Fig. 2. Block Diagram of the DAQ
This family of devices offers the advantages of all PIC18F24550
microcontrollers namely, high computational performance at an
economical price with the addition of high endurance, enhanced
flash program memory [7]. In addition to these features, the
PIC18F24550 family introduces design enhancements that make
these microcontrollers a logical choice for many highperformance, power sensitive applications. All of the devices in the
PIC18F4550 family incorporate a range of features that can
significantly reduce power consumption during operation. Devices
in the PIC18F4550 family incorporate a fully featured Universal
Serial Bus communications module that is compliant with the USB
Specification Revision 2.0. The module supports both low-speed
and full-speed communication for all supported data transfer types.
It also incorporates its own on-chip transceiver and 3.3V regulator
and supports the use of external transceivers and voltage
regulators. All of the devices in this family offer twelve different
oscillator options, allowing users a wide range of choices in
developing application hardware.
Asynchronous dual clock operation, allowing the USB module to
run from a high-frequency oscillator while the rest of the
microcontroller is clocked from an internal low-power oscillator.
Besides its availability as a clock source, the internal oscillator
block provides a stable reference source that gives the family
additional features for robust operation:
• Fail-Safe Clock Monitor: This option constantly monitors the
main clock source against a reference signal provided by the
internal oscillator. If a clock failure occurs, the controller is
switched to the internal oscillator block, allowing for continued
low-speed operation or a safe application shutdown.
• Two-Speed Start-up: This option allows the internal oscillator to
serve as the clock source from Power-on Reset, or wake-up from
Sleep mode, until the primary clock source is available.
Other Special Features
• Memory Endurance: The Enhanced Flash cells for both program
memory and data EEPROM are rated to last for many thousands
of erase/write cycles – up to 100,000 for program memory and
1,000,000 for EEPROM. Data retention without refresh is
conservatively estimated to be greater than 40 years.
• Self-Programmability: These devices can write to their own
program memory spaces under internal software control. By using
a bootloader routine, located in the protected Boot Block at the top
of program memory, it becomes possible to create an application
that can update itself in the field.
• Extended Instruction Set: The PIC18F24550 family introduces
an optional extension to the PIC18 instruction set, which adds 8
new instructions and an Indexed Literal Offset Addressing mode.
This extension, enabled as a device configuration option, has
been specifically designed to optimize re-entrant application code
originally developed in high-level languages such as C.
• Enhanced CCP Module: In PWM mode, this module provides 1,
2 or 4 modulated outputs for controlling half-bridge and fullbridge drivers. Other features include auto-shutdown for disabling
PWM outputs on interrupt or other select conditions and autorestart to reactivate outputs once the condition has cleared.
• Enhanced Addressable USART: This serial communication
module is capable of standard RS-232 operation and provides
support for the LIN bus protocol. Other enhancements include
Automatic Baud Rate Detection and a 16-bit Baud Rate Generator
for improved resolution. When the microcontroller is using the
internal oscillator block, the EUSART provides stable operation
for applications that talk to the outside world without using an
external crystal (or its accompanying power requirement).
• 10-Bit A/D Converter: This module incorporates programmable
acquisition time, allowing for a channel to be selected and a
conversion to be initiated, without waiting for a sampling period
and thus, reducing code overhead.
• Dedicated ICD/ICSP Port: These devices introduce the use of
debugger and programming pins that are not multiplexed with
other microcontroller features. Offered as an option in select
packages, this feature allows users to develop I/O intensive
applications while retaining the ability to program and debug in the
circuit.
Configuration and Data Transmission of the DAQ.
The DAQ can be configured to be connected with other bluetooth
device knowing the Media Access Control (MAC) address. Fig. 3
shows a schematic of the card. This device can operate in two
different modes DAQ Bluetooth and DAQ USB – Bluetooth.
1) DAQ Bluetooth: Receives and transmits information on the
card. The Bluetooth module configuration is made directly by
reading a dedicated input pin for this purpose.
2) DAQ USB – Bluetooth: The card is connected via USB to the
computer as a data acquisition card USB, sending and receiving
the information to another Bluetooth device.
Fig. 3. Bluetooth DAQ Schematic
The programming of the firmware is developed in C, using the PIC
C compiler for the recognition of the card in USB mode through
drives of Microchip mchpusb.cat, mchpusb.sys, mchpusb64.sys,
and mchpusb.inf. The configuration and ad hoc connection with
another Bluetooth device is designed via AT commands, either
stored in the microcontroller or transmitted through the user
interface working in USB mode [8]. All the information needed in
the Bluetooth DAQ mode is stored in the ROM of the PIC which
is activated through the sensing PIN C0. The DAQ in any of two
modes of operation works as the master who initiates the
connection. Others Bluetooth devices in a computer can be used as
slaves. The algorithm of the microcontroller has four important
steps. It is shown in Fig. 4.
1.
2.
3.
4.
Configuration of the Bluetooth module, through the
detection of the C0 PIN, which executes the code stored
in the CIP for this purpose.
Connection or disconnection of the module, with another
Bluetooth device.
Configuration and mapping in the microcontroller, for
the analog and digital inputs.
Configuration and mapping in the microcontroller, for
the analog outputs - PWM and digital outputs.
3. SOFTWARE
User interface for controlling the card is held under the
programming language Visual C. This consists of three parts
Initialization and recognition of the card, Data Acquisition and
Robot Control [9-13].
Initialization and recognition of the card
As we can see in Fig. 5, on this step, the card recognizes possible
failures and connects the configuration via USB or via Bluetooth
COM port. In USB mode it works as a Communications Device
Class. When the card is installed and recognized by Windows, the
Bluetooth module can be configured to transmit and acquiring data
[9].
Fig. 4. Firmware algorithm
Fig. 5. Initialization and connection
Data Acquisition
The data acquisition window is depicted in Fig. 6. This stage is
focused on acquiring and transmitting data in the Bluetooth
data acquisition mode or as data acquisition USB-Bluetooth.
The outputs are selected and the distance where the card is
located is displayed using LEDs. Digital inputs are read from
the card but only one analog channel can be read by sweeping
6 possible analog inputs. The analog outputs are transmitted
through pulse width modulation.
Robot Control
In this step the card sends the paths, positions and commands
to run the robot. For example, the position of the shoulder,
elbow and wrist. Control and address data, are transmitted as a
floating, detached by nibble, so that the robot can interpret
them. Fig. 7 depicts a specific routine to control a robot.
Fig. 9. Experimental Robot
Fig. 6. Data Acquisition in C #
P
T
1
1
C
C
7
2
6
2
4
1
2
D
N
G
D
N
G
9
E
O
C
C
1
3
0
5
1
0
A
3
1
6
7
8
1
3
A
5
A
5
2
A
1
1
A
4
0
A
2
6
9
1
7
0
8
2
9
2
2
1
5
A
2
3
1
1
3
4
2
1
25
Connector
D
N
D
2
A
5
2
3
1
1
A
2
A
0
SN74LS245N
G
The control of an arm is a training platform for robot
manipulators. This has theoretical and practical interest for
experimental validation of new controller designs. An arm has
been manufactured and built in the “Facultad de Ciencias de la
Electrónica” of the “Benemérita Universidad Autónoma de
Puebla”. The robot has a drive with three degrees of freedom
[13, 14]. In the Fig. 8 we can observe the communication
system.
1
0
D
N
G
0
1
10
Header
4. APPLICATION
1
9
2
8
A
9
7
A
7
8
8
6
A
6
7
5
A
5
6
4
A
4
5
3
A
3
4
2
A
2
3
1
A
1
8
B
7
B
6
B
5
B
1
B
3
2
1
C
C
V
D
N
8
G
B
1
1
B
1
5
6
7
B
Fig. 7. Robot control
4
4
1
3
1
2
1
1
1
8
P
DIR
1
BLUETOOTH
DAQ
V
2
U
DIGITAL
OUT
V
J
L
In addition, the control of the robot needs a digital signal
conditioning step. The circuit connected to the digital output
port of the card is shown in Fig. 10.
Fig. 11 shows the complete Bluetooth DAQ.
Fig. 10. Digital signal conditioning
Fig. 8. Communication System
The control algorithm, programming in Borland C, is loaded in
the robot console. It receives external data through the parallel
port. In Fig. 9 we can observe the experimental robot.
Figura 11. Bluetooth DAQ
5. CONCLUSIONS
This paper has shown a simple but successful design of a
Bluetooth data acquisition card for the control of manipulator
robots. Industrial applications involving this system can
benefit from the use of wireless communication technologies.
The localization and tracking of components, the coordination
of autonomous transport vehicles and mobile robots, as well as
applications involving distributed control are all areas in which
wireless technologies could be used in an industrial
environment.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
W. Stallings, Wireless Communications and Networking. Prentice Hall.
IEEE Computer Society. Part 15.1: Wireless medium access control
(MAC) and physical layer (PHY) specifications for wireless personal
area networks (WPANs). IEEE Std 802.15.1 , New York, 14 June 2005.
Bluetooth SIG, Inc. BLUETOOTH SPECIFICATION Version 2.1 +
EDR [vol 0]. The United State, 26 de July de 2007.
Bluetooth SIG, Inc. RFCOMM with TS 07.10 Serial Port Emulation,
The United State, March 2003.
Amar Palacherla, Microchip Technology Inc. Using PWM to Generate
Analog Output, U.S.A, 2002, pp. 1-4.
Ross M. Fosler and Rodger Richey, Microchip Technology Inc. A
FLASH Bootloader for PIC16 and PIC18 Devices, U.S.A, 2002, pp. 138.
Microchip. PIC18F2455/2550/4455/4550 Data Sheet, 28/40/44-Pin,
High Performance, Enhanced Flash, USB Microcontrollers with nano
Watt Technology.
Sena Technologies, Inc. User Guide for the Parani-ESD1000, Korea,
November 2009.
Custom Computer Services, Inc, PCD C Compiler Reference Manual,
U.S.A, February 2010.
Rawin Rojvanit Microchip Technology Inc. Migrating Applications to
USB from RS-232 UART with Minimal Impact on PC Software,
U.S.A, 2004, pp. 1-16.
Axelson, J. USB Complete: The Developer’s Guide. United States of
America: Distributed by Independent Publishers Group, 2009.
Kelly R & Santibáñez V. Control de Moviminento de Robots
Manipuladores. Madrid España: Person Educación, 2003.
Craig, J.J. Introducction to robotics: Mechanics and control. AddisonWesley, Reading, MA. 1989.
Arturo Corona, Jorge Moctezuma, Fernando Reyes, Roberto Campos,
“Nueva plataforma de Entrenamiento para Robots Manipuladores”, El
HOMBRE Y LA MAQUINA numero 28, Colombia, enero-junio 2007,
pp. 108-115.