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Mobile Robot Controlled by a Phone

Amit K SinghSudip Pathak

Advisor: Dr. Tarek M. SobhTechnical Advisors: Professor S. Grodzinsky, Professor L. Hmurcik

Computer Science and EngineeringUniversity of Bridgeport

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Table of Contents:

1. Abstract ------------------------------------------------------- 22. Objective ------------------------------------------------------- 3

3. Introduction and Background Search ----------------------------- 3

4. Design Ideas -------------------------------------------------------- 7

a) Build a robot with a phone chip --------------------------- 7

b) Using the Internet telephony server --------------------- 8

c) A combination of the Phone and the Internet -------- 9

5. Methodology and Justification ---------------------------------- 12

6. Hardware/software and test equipment required ------------- 12

7. Implementation -------------------------------------------------------- 13A) Ring Detect and Phone Line Connection ------------- 15

i) Relay Switch -------------------------------------------- 16

B) DTMF Decoder --------------------------------------------- 18

C) FPGA Control --------------------------------------------- 20

i) Clock Division Module ---------------------------------- 21

ii) Ring Detect Module ---------------------------------- 23

iii) Robot Control Module ---------------------------------- 25

iv) Motor Control module ---------------------------------- 32

D) Assembling various parts and combining thedifferent modules --------------------------------------------- 35

8. Economic Analysis ---------------------------------------------------- 35

9. Safety Concern ------------------------------------------------------- 36

10. Conclusions and Future Directions ------------------------------ - 37

11. Appendices

A) VHDL Source Code for Clock Division Module ----------- 39

B) VHDL Source Code for Ring Detect Module ----------- 42

C) VHDL Source Code for Robot Control Module ----------- 43

D) VHDL Source Code for MotorControl Module ----------- 49

E) Combine all the VHDL modules -------------------------------- 51

12. Bibliography ------------------------------------------------------- 52

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Abstract:

Mobile Robots have numerous applications: unmanned exploration, land mine removal,

energy plants and manufacturing factories. Robotics as a field has a long history since 1801

when Joseph Jacquard invented a textile machine, which operated by punch cards. Today

over 100,000 robots are in use in the United States, compared with millions of computers and

cell phones. Robotics, as an area, has undergone a significant change in the last two

decades. Dramatic improvements in optimization, profound changes in costs and vast

increases in applications have made it possible for us to consider a design of a personal

robot.

We introduce a cost-effective robot that may be used in our everyday life. The idea is simple

and has been the focus of many researchers, namely using a remote controller to request a

robot to perform a specific job just as a remote controller is used for a TV to change

channels. Our focus is on reducing the costs and making the robot controllable by a device

that almost every person in the United States owns a phone. With the introduction of video

cell phones it will be possible for the user to see the robotic movement in real-time. Examples

include calling the robot on the way home from work and have it do various jobs like

vacuum the room and sprinkle the garden. This could also be done by logging on to the web

server via an internet connected device and sending signals to the robot, or directly sending

specific commands to the robot through cellular phones to a wireless server at home (with or

without a web connection).

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Objective:

The objective of this project is to introduce an idea of controlling a personal robot via phone line

for practical applications in our daily life. This project is divided into two sections:

i) Conduct research on various applications of robotic systems and their feasibility.

ii) Focusing on the design and actual implementation of a control mechanism of the

robot over the existing phone lines, more precisely analog copper wires.

Introduction and Background Search:

A robot is a re-programmable multifunctional manipulator designed to move material, parts, tools,

or specialized devices through variable programmed motions for the performance of a variety of

tasks1.

Today, with the dawn of the new millennium, we are perusing a new technology. It would have

been hard to imagine how microprocessor-based computers could evolve in the 20 th century. It

may be the same with the personal robots, the only difference being that we can imagine and

visualize robots working in our homes for us. We consider personal robots to be at the same

stage that personal computers were in the 1970s. However, with the advancement in computer

technology, it might take only 10 to15 more years for the personal robots to be ubiquitous.

In the early days, robots were built to replace human workers, especially, in the automotive

industry. The first industrial robot saw service in 1962 in a car factory run by General Motors in

Trenton, New Jersey. The robot lifted hot pieces of metal from a die-casting machine and stacked

them. The idea that robots would be universal machines, capable of rapid reprogramming for a

1 The definition developed by the Robot Institute of America (RIA), a group within Society of

Manufacturing Engineers (SME)

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wide variety of tasks, motivated the development of the PUMA (Programmable Universal Machine

for Assembly) by Unimation in 1978.

In practice, early robots were hard to reprogram and failed to compete with humans. Spraying

and welding were some of the few applications carried out by robots. SCARA (Selectively

Compliant Articulated Robot Arm) robots developed were for the assembly tasks in Japan, i.e. for

mounting components on printed circuit boards for the electronics industry.

The ideas about robots were then limited to consider those tasks that a human could not perform.

These include:

1) Working in hazardous environments, for example land mines, offshore oil or nuclear

industry.

2) Working in a place inaccessible to humans, for example outer space or on the seabed.

3) Work on larger scale that humans find difficult, for example a large assembly plant or

handling tasks, and to manipulate objects at the microscopic scale.

The early robots were more expensive and developing them required the expenditure of millions

of dollars in research. For example, Manny2, an anthropomorphic manikin developed at Battelle's

Pacific Northwest Laboratories in Richand, Washington, took 12 researchers 3 years and $2

million to build.

2 Manny has 42 degrees of freedom and was delivered to the US Army's Dugway Proving Ground in Utah in 1989.

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Why are we considering this project?

In the last 30 years we have seen technology and technology application grow dramatically. With

the introduction of personal computers in 1970s and wireless communications around the same

time, technology has advanced from the industrial age to the information age. Dramatic

improvements in optimization, profound changes in costs and vast increases in applications have

made it possible for us to consider the design of a personal robot. In fact some personal robots

are already out in the market for limited applications.

Sony Corporation has introduced Aibo, the intelligent pet. On May 12, 1999, Designed for home

or office, a new smart and affordable personal robot was launched by Probotics, Inc. called Cye,

The compact personal robot can do a wide variety of tasks such as carry dishes, deliver mail,

lead guests to a conference room and vacuum the carpet. Using wireless communications

technology, Cye is controlled by Map-N-Zap, a highly intuitive graphical user interface (GUI)

loaded on any PC with a 133 MHz Chip or higher.

Figure 1:

Cye in Living RoomPhotograph by: Neoforma Design

Figure 2:

"Orange Cye-sr with Cordless Vac"Photograph by: Neoforma Design

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A prototype robot named R100 developed at NEC's Central Research Laboratories is capable of

visual recognition, voice recognition, mechatronics and Internet communication technologies, the

robot can recognize individual faces, understand verbal commands, and move smoothly around

the home, avoiding such obstacles as tables and chairs (NEC).

Computers may be indispensable today, but they are not that friendly for many of us. NEC is

conducting research on a personal robot to break through the barrier between people and

computers. Their aim is to develop a robot companion who will become like a family member -

dependable, kind, considerate but at times maybe a little cranky and just human like the rest of

us (NEC).

From our background search we conclude that controlling a robot over the existing telephone

lines has not yet been implemented. To implement a control mechanism for controlling any robot

over a telephone line appears challenging. Hence the idea of controlling a mobile robot via phone

sounds fascinating to pursue for our senior year project.

Figure 3:R100 personal robot designed by NEC. Thisrobot communicates by talking, listening,responding and acting which is different from

the ones that communicate via keyboard, dialand buttons.

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Design Ideas:

Based on our research, we came up with these three different methods to implement our idea of

controlling a robot over the phone.

a. Build a robot with a phone chip.

b. Using the Internet Telephony Server.

c. A combination of the Phone and Internet for robot control

a) Build a robot with a phone chip

One way to communicate with the robot could be to build a robot with a phone chip (similar to

Lucent Technologies phone on a chip). Various types of phones exist in the market. Initially, we

thought of using the Personal Communications Services (PCS). The radio spectrum in the 1.8 -

2GHz range is typically used for this mode of digital cellular transmission that competes with

analog and digital services in the 800Mhz and 900MHz bands. There are several advantages of

using digital transmission. A digital signal can pass through an arbitrary number of regenerators

with no loss in signal and thus travel long distances with no information loss. Voice, data, music

and images can be interspersed to make efficient use of circuits and equipment. Much higher

data rates are possible using existing lines. Compared to analog transmission, it is much cheaper

than analog transmission as we only need to distinguish between 0 and 1.

An example of this system is calling the robot on the way home and requesting the robot to

vacuum the room or take a coke can out of the refrigerator.

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b)Using the Internet Telephony Server

Another approach to the same design problem could be through using the Internet to

communicate with the robot using the same PCS wireless technique. An Internet telephony

server links phone lines to the Internet. With the Internet, we can connect to the web server using

ASP or CGI programs. The web server then generates the easily decodable touch-tone. Then the

same techniques would be used on the receiving end of the robot as described earlier. One of the

added features of using the internet and the telephony server would be the ability to display a

simulation of the robotic movements at the remote location or a real time video feedback system

can be implemented.

Figure 4: An application of Robot with a phonechip

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Figure 5: Example of using Internet Telephony Server

c) A combination of the Phone and Internet for robot control

A third possibility for personal robot control is to merge both of the above mentioned approaches

and use both direct dialing system and access through the Internet. Figure 6 shows the flexibility

of using an alternate system when the other system is unavailable or more expensive. For

example, if we are in some third world country and need to access the robot in our apartment in

California, then using the internet will be more economic than using a phone system. Similarly,

when we are driving on I-95 and need to access the robot to clean up our apartment before we

get back, then using a phone will definitely be the only option.

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Figure 6:

Flowchart showing the combination of the two design methods:

Call receiving unit

FPGA chip with decoderand kinematics logic

Robotmotors/sensors

Telephone unit placing acall directly to the Robot

Internet controlled telephonyserver used to communicate withthe receiving unit

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Another application Personal Robots may be used for is grocery shopping. The existing online

grocery shopping do home delivery at certain times. Optimistically, we can do grocery shopping

online and at the same time we can request our Phonebot to open the door, carry the delivery

and put it in the refrigerator. We know that the experiments with the robot in the field of surgery

are already being done, where a doctor can remotely monitor a patient and operate on him/her.

This idea can be further implemented by designing robots for the ambulances. This helps the

doctors to provide immediate care to the critical patients.

Figure 7: Combining the two design methods

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Methodology and Justification:

Considering the fast paced modern technology the new generation of engineers need to look a

step ahead. From the beginning of this project we focused primarily on communication with a

robot. Our main objective was, and is, to make the robots more user friendly and be able to

communicate with them as we can communicate with other people around the globe. Thus we

decided to design a simple prototype of a robot that can be controlled via phone - Phonebot. To

keep it simple, we will start with a design similar to the one described under design idea (a).

Hardware/Software and Test Equipment Required

Hardware Requirements:

Flex 10K70 ChipsetTalrik II Robot (including the Servo motors and Sensors)TelePhone SetTeltone's M-8870-01 ChipSPST 90-2323, 5V relay switch from RadioShack3.58MHz Crystal Oscillators (Part # )Variable Power SupplyResistors, Capacitors and Diodes

Software Requirements:

Altera's MaxPlus IIOrCADHTMLCGI/ASPJavaMatlab

Test Equipment:

OscilloscopeLogic AnalyzerMultimetersNerd-Kit

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Implementation

As mentioned above, our primary objective is to communicate and control the Phonebot over the

analog phone system. First a call is placed to the Phonebot using either Plain Old Telephony

System (POTS) or a Personal Communication System (PCS), or by using the telephony server

via Internet. Once the Phonebot receives the ring, a ring detector circuit detects it and the call is

complete by establishing a connection between the phone chip and the FPGA chip.

The project was implemented using a top-down process. We started by defining various modules.

Initially we broke down the project into two parts sending a signal through the phone line and

robot control with the FPGA device. However, during the implementation we found out that

receiving and decoding signal coming through the phone line required a lot of work. This part was

further broken down into two modules and we divided the work as shown (the description of each

module follows the basic block diagram of Phonebot and VHDL programming section is described

separately under FPGA control):

A) Ring Detect and connect phone line Sudip Pathak

B) DTMF decoder Amit Singh

The robot control part also required a new module for the controlling the motors. Hence this part

was renamed as FPGA control and divided into two parts and the lead person on each part is as

follows:

C) FPGA Control

i) Clock Division (VHDL program)- Amit Singh

ii) Ring Detect (VHDL program) Sudip Pathak

iii) Motor Control (VHDL program) Sudip Pathak

iv) Robot Control (VHDL program) Amit Singh

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In the end we worked together to:

D) Assembling various parts of Phonebot and combining the different VHDL modules.

However, we had to consult more often and work very closely in order to synchronize the different

modules.

Figure 8: PHONEBOT Basic Block Diagram

PHONEBOT

PHONE ROBOT

RingDetect

And LineConnect

DTMFDecoder

+

Phone

line

FPGA (FLEX 10K20/10K70)

Robot

Control

Motor /

SensorControl

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A)Ring Detect and Phone Line Connection

When the phone rings, the telephone company is sending a ringing signal, which is an AC

waveform. The common frequency used in the United States is 20 HZ and in Europe is typically

25 Hz and it can be any frequency between 15 and 68 Hz. Most of the world uses frequencies

between 20 and 40 Hz. The voltage at the subscribers end depends upon loop length and

number of ringers attached to the line; it could be between 40 and 150 Volts. There are various

types of ring detectors available in the market. We found the following circuit for the ring detector

very easy and inexpensive to design. It is very important that we connect the diodes the right

way.

C1 .1 ufCR1,CR2,CR3 1N914

C2 10 uFR1,R3 100KR2 10K

Figure 9: Phone detect circuit3

3Ring detect circuit obtained from the website,

http://www.ee.washington.edu/circuit_archive/circuits/F_ASCII_Schem_Tel.html

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The telephone line mostly has only DC (-48V) and/or small signal AC (audio). In the circuit shown

in Figure 9, capacitor C1 blocks the DC and the voltage divider circuit obtained from R3 and R2

resistors prevent the low level AC from having any effect on the circuit. Now when the telephone

rings, it brings about 90V RMS of AC at 20Hz. When the telephone rings, the capacitor C2 is

charged. Diodes CR1 and CR2 guarantee that the output (ring detect logic) does not exceed the

power supply levels and prevent any damages to other circuits driven from its output. Since C2

and R1 have the time constants of 1s, the output goes low for 1second after the ring stops. This

pulse is to be detected and used for connecting the telephone circuit by the FPGA chip.

The circuit worked exactly as expected and we had no major problem wiring the circuit and

testing it. Unfortunately, while debugging the circuit at a later stage we almost damaged the

bread-board by connecting the VCC and GND the opposite way. This provided enough voltage

for the diode to be reverse biased and the heat produced was sufficient to almost melt the board.

i) Relay switch for establishing phone line connection

After detecting the circuit the next step was to establish the phone line connection. First we tried

to use a BJT switch but this complicated the problem even more as the signal we needed to pass

was negative 48 DC. Instead, using an electromagnetic switch was a lot easier approach. Using

the idea of electromagnetism, an armature can be attracted by the electromagnet, a spring and a

set of electrical contacts. The circuit is depicted in Figure 10.

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Figure 10: Schematic capture of the relay circuit used for the connection.

We noticed that a relay switch was listed in the OrCAD library and this made us think that it

should be available in the market. Hence we found several kinds of these in the RadioShack web-

site. We bought the SPST 90-2323, 5V relay switch from RadioShack. In Figure 10 when a

current flows around the electromagnet, a magnetic field is created around the electromagnet

resulting different polarities at the ends of the electromagnet. Thus, the electromagnet attracts the

top metal leaf to close the upper circuit. When the electromagnet is not activated, the spring pulls

the switch open. In our project, once the ring signal is detected we activate the switch by sending

0V signal from the Altera board to close the telephone path, which completes the telephone

circuit. This is equivalent to picking up the phone to establish a connection. We were originally

thinking of sending 5V from the Altera board and grounding the other end of the coil of wire.

However this did not work and we assume that it could be because not enough current was

flowing out of the Alteras output pins. Thus we switched them around and with VCC and output

pin 0V there was sufficient current flowing through the wire to charge the electromagnet in the

relay switch.

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B) DTMF Decoder

Dual Tone Multi Frequency (DTMF) signals are used for speed dialing and replace the

conventional rotary dialing system. These signals correspond to the digits on the dial pad of any

modern touch-tone phones. Each of those touch-tones is constructed with the combination of two

different frequencies. This information can be utilized to find out which button was pressed on the

keypad and can be used for various applications. The construction of the signals according to

different frequencies is shown in table as:

High Frequency Values (Hz)

1209 1336 1477 1633

697 1 2 3 A

Low Frequency 770 4 5 6 B

Values (Hz) 852 7 8 9 C

941 * 0 # D

Table 1: Signals related to different frequencis

These frequencies can be decoded using precise filters and then we can decode which digit was

pressed depending upon these decoded frequencies. We used the M-8870-01 DTMF decoder

chip to decode this information. The chip uses a series of low pass and high pass filters to

decode the frequencies. Then it uses a digital detection algorithm and a code converter to provide

its output in the form of four binary output data. This data is supplied to the FPGA chip for further

use. The internal circuit used by the chip to decode the DTMF is shown in figure 11.

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Figure 11: Internal circuit of the DTMF decoder (from Teltones Data Sheet).

There are various problems in decoding these DTMF signals such as Talk off, Talk down,

Substandard DTMF, etc. which can provide false DTMF signals at times. Talk off errors occur

when false signal is detected due to voice or other noise. Talk down errors occur when we miss

some of the detected signals due to line noise or outgoing/incoming voice. Substandard DTMF

are the errors in generated DTMF signals due to substandard components in the generating

device such as the telephone set or the keypad. Most of these errors can be eliminated if we use

more precise components (resistors and capacitors). While testing the DTMF decoder circuit we

observed that a slight change in the voltage, current, resistors or capacitors could trigger a

significant errors. It was realized while testing the circuit that the Teltones decoder works under

very specific ranges of voltage and current. It was very strange for us to find out that the 5V

device actually worked better with 3V. We are suspicious that this could actually be a 3.3V

device.

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C) FPGA Control

For the controller we decided to use the Alteras Flex 10K70 chip. The FPGAs contain arrays of

logic cells, and enable designing real systems to operate at increasingly higher frequencies. They

have the ability to increase integration, to place more and more electronics in a chip and use all

available gates within the FPGA thereby providing cost-effective solutions. The most important

factor for selecting this chip is that we can program and reprogram the device while it is in a

system. This provides us with a great flexibility for using the Phonebot. The Phonebot can be

programmed within few minutes to do any task. Once programmed the robot will have the

intelligence to complete the requested task. The FPGA chip can also be programmed to store

the complex kinematics of the robot and send a feedback, using the DTMF generator via the

same phone line (this has not been implemented in this project). For our project, Flex 10K70 is

used to control the Phonebot based on the signals decoded by the DTMF decoder.

The FPGA chip decodes the 4-bit binary output (from the DTMF decoder) into its useful

commands for the robot. The device is programmed to decode the DTMF signals, issue

commands to the robot, and send pulses to the servo-motors based on the logic programmed into

it. The controller consists of these four modules:

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Clock DivisionModule

i) Clock Division Module

This module divides the 25MHz clock of Alteras University Board into slower clocks so that we

can provide the precise timing for the servo-motors because these motors work at pulses in the

order of milliseconds. As shown in Figure 12, the 25MHz clock is divided into 1Mhz, 100Khz,

10KHz, 10Hx and 1Hz. The Robot Control module requires 10Hz clock whereas the Motor

Control module requires 10KHz clock. The VHDL source code for this module is provided in

Appendix A.

Clock_1MHz

Clock_100KHz

Clock_25MHz Clock_10KHz

Clock_10Hz

Clock_1Hz

Figure 12: Block diagram of clock division module

Figure 13: Flow chart of Clock Division module

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Clock Division:Clock change within 20us:

Clock changes at 13 cycles of25MHz clock (for 1MHz clock)

Clock change within 1ms range:

Clock changes at 5 cycles of100KHz clock (for 10KHz clock)

Clock change within 20ms range:

Clock changes at 5 cycles of10KHz clock (for 1KHz clock)

Figure 14: Timing diagrams for clock division

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Ring Detect Module

ii) Ring Detect Module

This module takes its input from the ring detector circuit and the DTMF decoder, provides output

to the relay for closing or opening the telephone circuit. As soon as a ring is detected this module

provides a 0V signal to the relay and thus closes the circuit. When it senses a DTMF code for

digit 0, it opens the switch again. We had a small problem while disconnecting the phone. The

FPGA device stored the code for digit 0 even after it was disconnected and for the same reason

next time we dialed up, it would connect and disconnect on its own. This problem was resolved

by resetting the signals in the FPGA device on the falling edge of the SB signal (SB signal goes

high when there is a valid code detected by the DTMF decoder).

SB

Clear

Ring_Detect Ring_Connect

D (Touch Tones)

Figure 16: Ring Detect Timing Diagram

Figure 15 : Block diagram of Ring Detect Module

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Figure 17: Ring Detect Module Flow Chart

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Robot ControlModule

iii)Robot Control Module

This module programes the movement of the robot according to the detected DTMF signals. It

determines the path of the robot and provides a signal for the servo motor control module

controlling the direction and the duration of running the motors. For example, if we press 7, it

moves the robot in forward direction for 4 seconds; if we press 8, the Phonebot moves in reverse

direction for 4 seconds; and if we press #, Phonebot comes to a complete stop. We also added

few bump switches to the Phonebot. These bump switches send a high signal to the FPGA when

they are bumped. Depending upon which bumper detects switch closures, the FPGA device

determines where the collision occurred and issues a signal to the Phonebot to change the

direction of its path.

Clk_10 Hz lmotor_speed

SB rmotor_speed

D lmotor_dir

Sensors (S1,S2,S3) rmotor_dir

Figure 18: Robot Control Module Block Diagram

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Figure 19: Robot Control Module Flow Chart

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Motor ControlModule

iv) Motor Control Module

The Phonebot has two servo motors to aid its movement. First we had to hack these motors to

create a DC gearhead motor. The information on hacking the servos was obtained from

Mekatronix manual for the Talrik II robot (). The hacked servos work on Pulse Width Modulation

(PWM). This module provides the robot with pulses at specific times. If we provide a pulse for 1 to

1.5ms, then the motor spins in one direction and if we provide a pulse for 1.5 to 2ms, then the

motor spins in another direction. The pulses have to be issued in an interval of about 20ms. This

module takes care of this pulse generation timing.

Clk_10KHzLmotor_speedRmotor_speed lmotorLmotor_dirRmotor_dir rmotor

Figure 21: Motor Control Block Diagram

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Figure 22: Motor Control Flow Chart

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Figure 23: Motor Control Timing Diagrams

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D) Assembling various parts of Phonebot and combining the different VHDL modules

The final task in the project involved assembling the different modules together. Putting together

the physical parts was a lot more arduous task. We had to be make a common ground for the

FPGA device, the circuit we designed for the ring detection and the DTMF decoder. The Altera

was not detecting the decoded signals produced by the DTMF decoder until we made a common

ground. The main controller program was implemented in structural format combining the various

components. The VHDL source code for combining all the different modules is provided in

Appendix E.

Economic Analysis:

Overall cost for the Phonebot was very small. The following table shows the amount we had to

spend to design the Phonebot.

Part QTY Per unit

*Servo Motorsand Wheels

- - 10.00

*FPGA chip(Flex 10k70)

- - N/A

DTMF Decoder(Teltone M-8870-01)

1 1.50 1.50

Relay Switch(SPST 90-2323)

1 2.40 2.40

Oscillator 1 3.00 3.00Capacitors 5 0.60 3.00Resistors 8 ~ 0.50 4.00Diodes 3 0.50 1.50Wires/Circuit Board 1 pk 5.00 5.00

Sensors 4 2.00 8.00*Wood - - 10.009V Adapter /Ni-MH Battery

1 15.00 15.00

TOTAL COST (Estimate) $ 63.40 + FPGA Chip

Prices were quoted from RadioShacks website (http://www.radioshack.com)* Estimated price for comparison purpose only

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Assuming the FPGA chip costs around $100, we can build a Phonebot for about $163.40.

Compared to CYE which costs $800.00 or Aibo which costs $2500.00, Phonebot is very cheap. If

we were to do a mass production, these figures would drop significantly.

Safety Concerns:

Phonebot does require some safety measures.

i) One should always keep in mind that there is 90V AC coming from the telephone

wire when a telephone rings. During our implementation phase we took an extra

precaution. Never touch the wires when a phone is ringing.

ii) Phonebot has a wire connecting it to the phone jack on the wall. If this were to be a

commercial product, we could either use a remote phone jack that is available in the

market.

Depending upon the task the Phonebot is programmed to carry out, more safety measures may

be required. The Phonebot does not have a cover. Putting a cover around the Phonebot would

protect anyone from tampering with the wires.

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Conclusions and Future Directions:

According to a research conducted by Nortel networks, there are 750 million people in the world

who use telephones. Hence, there are 750 million people in the world who can dial to our

Phonebot and control it. Probably this is the first of its kind. The current phone number assigned

to the Phonebot is (203) 576 4156.

The idea of Phonebot evolved from our original idea of designing a wireless controlled robot. It

was during our research phase that we started considering the idea of controlling a robot via a

telephone line. We encountered various problems as described under various modules. Besides

these, we did have problems getting the right equipment at the right time. It was only after we got

24 hrs access to the EE labs that we found out we really had all the resources required to

implement a project like this. For several days we tried to build a circuit to decode the DTMF

signals from the Teltones 5V device and we were not progressing. After we got full access to the

EE labs, we had all the resources we needed including the logic analyzer, oscilloscope, power

supplies, etc.

Designing the Phonebot was an enthralling project. This project required:

An understanding of Robotics

Considerate knowledge of FPGAs and proficiency in VHDL

Exceptional knowledge of Electronics and Circuit design

Hands on experience on Assembling/Soldering parts

Fair knowledge of Telecommunications

In several instances we realized that the courses we took during our last 3 /4 years were crucial

and sufficient for us to be able to implement a project like this. This project involved an extensive

research during the first semester and a successful implementation during the 2nd semester of our

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senior year. This project not only utilized our knowledge and skills but refined them to a

professional level.

Upon successfully implementing our idea of Phonebot, we have gained more confidence in our

skills learned in the last few years. However, there are several features that could be added to the

Phonebot:

- Instead of the DTMF decoder, we can use a voice encoder/decoder. Similar to a DTMF

decoder, the voice decoder would recognize certain frequencies and depending upon

those frequencies, the Phonebot can be programmed to do certain tasks. This feature

could also be used for security purpose.

- Program the Phonebot to do specific tasks like vacuum a room, take out a coke can

from the refregerator.

- Using more sensors and a visual feedback would make the Phonebot more animated

and will be able to carry out more tasks.

- Integrating with the Internet is another possibility that would add more access to the

Phonebot. This would be very suitable for grocery shopping. When a person does an

online grocery shopping, the Phonebot would know what were bought and what to expect

when a delivery person comes. Besides, Phonebot could also be programmed to keep

track of what is available in the stock.

This shows that a list for improvements on Phonebot and various application it could be used is

very long. Hence, we conclude that Phonebot has the potential to generate a new wave in the

modern technology.

This report is also available on the Computer Science and Engineering website under the

projects. A movie file is also included on the website. The current link to the website is

http://www.bridgeport.edu/cse/projects/phonebot/index.html .

Finally we thank our Professors at UB, especially Dr. T. Sobh, Professor S. Grodzinsky and

Professor L. Hmurcik for their guidance.

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APPENDIX A

--***************************************************--THIS PROGRAM DIVIDES THE 25MHz CLOCK OF THE ALTERA'S **

--UNIVERSITY BOARD INTO DIFFERENT SLOWER CLOCKS TO RUN **

--OTHER MODULES WHICH REQUIRE SLOWER CLOCKS **

--*********************************************************--*********************************************************

library IEEE;use IEEE.STD_LOGIC_1164.all;use IEEE.STD_LOGIC_ARITH.all;use IEEE.STD_LOGIC_UNSIGNED.all;

ENTITY clk_div IS

PORT(

clock_25Mhz : IN STD_LOGIC;clock_1MHz : OUT STD_LOGIC;clock_100KHz : OUT STD_LOGIC;clock_10KHz : OUT STD_LOGIC;

clock_1KHz : OUT STD_LOGIC;clock_100Hz : OUT STD_LOGIC;clock_10Hz : OUT STD_LOGIC;clock_1Hz : OUT STD_LOGIC);

END clk_div;

ARCHITECTURE a OF clk_div IS

SIGNAL count_1Mhz: STD_LOGIC_VECTOR(4 DOWNTO 0);SIGNAL count_100Khz, count_10Khz,count_1Khz :STD_LOGIC_VECTOR(2 DOWNTO 0);SIGNAL count_100hz, count_10hz, count_1hz : STD_LOGIC_VECTOR(2 DOWNTO 0);SIGNAL clock_1Mhz_int, clock_100Khz_int,

clock_10Khz_int, clock_1Khz_int : STD_LOGIC;SIGNAL clock_100hz_int, clock_10Hz_int, clock_1Hz_int : STD_LOGIC;

BEGIN PROCESSBEGIN

-- This portion generates a 1MHz clock

WAIT UNTIL clock_25Mhz'EVENT and clock_25Mhz = '1';IF count_1Mhz < 24 THEN

count_1Mhz

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PROCESSBEGIN

WAIT UNTIL clock_1Mhz_int'EVENT and clock_1Mhz_int = '1';IF count_100Khz /= 4 THEN

count_100Khz

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IF count_1hz /= 4 THENcount_1hz

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APPENDIX B--THIS PROGRAM DETECTS THE TELEPHONE RING AND

--THEN CLOSES THE SWITCH TO COMPLETE THE PHONE

--CIRCUIT. IT ALSO OPENS THE SWITCH TO DISCONNECT

--THE PHONE AT THE END

library IEEE;use IEEE.STD_LOGIC_1164.all;

use IEEE.STD_LOGIC_ARITH.all;

use IEEE.STD_LOGIC_UNSIGNED.all;

ENTITY ring_detection IS

PORT(extra_pin : IN STD_LOGIC;

--CLEAR PIN TO DISCONNECT THE PHONE IN THE BEGINNING

D : IN STD_LOGIC_VECTOR(3 DOWNTO 0);

--TOUCH TONE DECODED FROM M-8870-01

ring_detect : IN STD_LOGIC;

--COMING FROM RING DETECT CIRCUIT

ring_connect : OUT STD_LOGIC);

END ring_detection;

ARCHITECTURE a OF ring_detection IS

BEGIN

PROCESS (ring_detect,extra_pin)

BEGIN

IF extra_pin = '0' THEN

--DISCONNECT THE PHONE IN THE BEGINNING

ring_connect

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APPENDIX C

--*********************************************************

--**THIS PROGRAM DECODES THE DTMF SIGNALS INTO USEFUL **

--**COMMANDS OF ROBOTIC MOVEMENT AND ALSO DEALS WITH **

--**THE INPUTS FROM SENSORS **

--*********************************************************-- Lmotor_dir 0=forward 1=reverse-- Rmotor_dir 1=forward 0=reverse-- Lmotor_speed 1 = GO 0 = STOP-- Rmotor_speed 1 = GO 0 = STOP--DTMF SIGNALS:--6 is for return back movement--7 is for forward movement--8 is for left turn--9 is for right turn--10 is for disconnect--11 is for specific path A--All the rest are for stop--********************************************************--********************************************************library IEEE;use IEEE.STD_LOGIC_1164.all;use IEEE.STD_LOGIC_ARITH.all;

use IEEE.STD_LOGIC_UNSIGNED.all;

ENTITY control_robot ISPORT(S1,S2,S3 : IN STD_LOGIC; --SENSORS

clock_10hz,SB : IN STD_LOGIC; --SB IS INDICATION OF NEW--TOUCH TONE DETECTION

D : IN STD_LOGIC_VECTOR(3 DOWNTO 0);--TOUCH TONE DECODED BY M-8870-01 CHIP

lmotor_speed, rmotor_speed : OUT STD_LOGIC; --STOP OR GO FOR ROBOTlmotor_dir, rmotor_dir : OUT STD_LOGIC);

--DIRECTION OF SPIN OF SERVO MOTORS

END control_robot;

ARCHITECTURE a OF control_robot IS

SIGNAL timer : STD_LOGIC_VECTOR(7 DOWNTO 0);SIGNAL D_flag : STD_LOGIC;TYPE STATE_TYPE IS (forward,forward2, turnleft,turnleft2,turnright,

turnright2,pathA,pathA2,pathA3,pathA4,return_back,return_back2,stop,rest,sensor,sense1,sense2,sense3);

SIGNAL state: STATE_TYPE;SIGNAL sensor_flag : STD_LOGIC;

BEGIN

-- State Machine to Control Robot

CONTROL_PROCESS: PROCESS (clock_10hz,SB)BEGIN

IF SB = '1' THEN --DETECTION OF A NEW TOUCH TONEstate

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state

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lmotor_speed

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state

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--ACTION FOR FRONT SENSORlmotor_speed

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SENSOR_DETECT: PROCESS(S1,S2,S3)BEGIN

IF (S1 = '1' OR S2 = '1' OR S3 = '1') THEN--SENSOR DETECTS AN OBSTACLE

sensor_flag

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APPENDIX D

--************************************************************

--**THIS PROGRAM PROVIDES THE PULSES FOR THE SERVO MOTORS **

--**AT SPECIFIC TIMES REQUIRED BY THE MOTORS FOR THEIR **

--**CLOCKWISE AND ANTI-CLOCKWISE MOTION. **

--************************************************************

LIBRARY IEEE;USE IEEE.STD_LOGIC_1164.ALL;USE IEEE.STD_LOGIC_ARITH.ALL;USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY motor_control ISPORT(clock_10khz : IN STD_LOGIC;

lmotor_dir, rmotor_dir : IN STD_LOGIC;--DIRECTION OF SPIN FOR MOTORS

lmotor_speed, rmotor_speed : IN STD_LOGIC;--GO OR STOP FOR MOTORS

lmotor, rmotor : OUT STD_LOGIC);--PULSES FOR THE TWO MOTORS

END motor_control;

ARCHITECTURE a OF motor_control ISSIGNAL count_motor: INTEGER RANGE 0 TO 200; --COUNTER TO COUNT UPTO 20ms

BEGINPROCESS

BEGINWAIT UNTIL clock_10Khz'EVENT AND clock_10Khz = '1';IF count_motor /=200 THEN

--RESET COUNTER AT EVERY 20ms

count_motor

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--RIGHT MOTOR MOVEMENT

CASE rmotor_dir ISWHEN '1' => --FORWARD SPIN

rmotor --REVERSE SPIN

rmotor NULL;END CASE;

ELSErmotor

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APPENDIX E

--*************************************************************

--*********MOBILE ROBOT CONTROLLED BY A PHONE******************

--*************************************************************

--**THIS PROGRAM COMBINES ALL THE INDIVIDUAL MODULES INTO A **

--**SINGLE MODULE TO BE DOWNLOADED ONTO THE FPGA CHIP TO **

--**CONTROL THE ROBOT.

**--*************************************************************

--*************************************************************

LIBRARY IEEE;USE IEEE.STD_LOGIC_1164.ALL;USE IEEE.STD_LOGIC_ARITH.ALL;USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY main ISPORT (clock, SB, ring_detect,extra_pin :IN STD_LOGIC;

S1,S2,S3 :IN STD_LOGIC;D :IN STD_LOGIC_VECTOR(3 DOWNTO 0);lmotor, rmotor, ring_connect :OUT STD_LOGIC);

END main;

ARCHITECTURE A OF main IS

SIGNALclock_1MHz_sig,clock_100KHz_sig,clock_10KHz_sig,clock_1KHz_sig,clock_100Hz_sig,clock_10Hz_sig,clock_1Hz_sig : STD_LOGIC;SIGNAL lmotor_speed_sig, rmotor_speed_sig : STD_LOGIC;SIGNAL lmotor_dir_sig, rmotor_dir_sig : STD_LOGIC;

COMPONENT clk_div --PROVIDES SLOWER CLOCKS FOR THE SERVOSPORT(

clock_25Mhz : IN STD_LOGIC;clock_1MHz : OUT STD_LOGIC;clock_100KHz : OUT STD_LOGIC;clock_10KHz : OUT STD_LOGIC;clock_1KHz : OUT STD_LOGIC;clock_100Hz : OUT STD_LOGIC;

clock_10Hz : OUT STD_LOGIC;clock_1Hz : OUT STD_LOGIC);

END COMPONENT;

COMPONENT ring_detection --CONNECTS THE PHONE LINE WHEN IT RINGSPORT(extra_pin : IN STD_LOGIC;

D : IN STD_LOGIC_VECTOR(3 DOWNTO 0);ring_detect : IN STD_LOGIC;ring_connec : OUT STD_LOGIC);

END COMPONENT;

COMPONENT control_robot --DETERMINES THE DIRECTION AND DURATION OFPORT(S1,S2,S3 : IN STD_LOGIC; --ROBOT'S MOVEMENT

clock_10hz, SB : IN STD_LOGIC;D : IN STD_LOGIC_VECTOR(3 DOWNTO 0);lmotor_speed, rmotor_speed : OUT STD_LOGIC;

lmotor_dir, rmotor_dir : OUT STD_LOGIC);END COMPONENT;

COMPONENT motor_control --PROVIDES PULSES FOR THE SERVO MOTORSPORT(clock_10khz : IN STD_LOGIC;

lmotor_dir, rmotor_dir : IN STD_LOGIC;lmotor_speed, rmotor_speed : IN STD_LOGIC;lmotor, rmotor : OUT STD_LOGIC);

END COMPONENT;

BEGIN

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U1: clk_div

PORT MAP(clock,clock_1MHz_sig,clock_100KHz_sig,clock_10KHz_sig,clock_1KHz_sig,clock_100Hz_sig,clock_10Hz_sig,clock_1Hz_sig);

U2: ring_detectionPORT MAP(extra_pin,D,ring_detect,ring_connect);

U3: control_robotPORT MAP(S1,S2,S3,clock_10Hz_sig,SB,D,lmotor_speed_sig,

rmotor_speed_sig,lmotor_dir_sig,rmotor_dir_sig);

U4: motor_controlPORT MAP(clock_10KHz_sig,lmotor_dir_sig,rmotor_dir_sig,

lmotor_speed_sig,rmotor_speed_sig,lmotor,rmotor);

END ;

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Bibliography:

1. Tanenbaum, Andrew S. Computer Networks, New Jersey, Prentice Hall.

2. Meyers, Robert A. Encyclopedia of Telecommunications, Academic Press Inc.

3. Skahill, Kevin. VHDL for Programmable Logic, Addition-Wesley, 1996.

4. Yalamanchili, Sudhakar. VHDL Starter's Guide, Prentice Hall, 1998.

5. Doty, Keith L. TALRIKII Assembly Manual, MekatronixTM, 1999.

6. Internet: http://www.wired.com/news/gizmos/0,1452,32930-3,00.html

7. Internet: http://ourworld.compuserve.com/homepages/Bill_Bowden/page3.htm#spr

8. Internet: http://www.phonezone.com/tutorial/index.htm

9. Internet: http://www.phm.lu/documentation/connectors/Serial.asp

10. Internet: http://www.attitude-long-distance.com/how_phones_work.htm

11. Internet: http://www.ee.washington.edu/circuit_archive/circuits/F_ASCII_Schem_Tel.html

12. Internet: http://www.howstuffworks.com/relay.htm

13. Internet: http://www.d2tech.com/dtmfbenefits.htm

14. Internet: ftp://ftp.teltone.com/pub/8870.pdf