Transcript robot Power Point - BasicX and Robotics

Robotics Demo
Chris Odom
www.basicxandrobotics.com
[email protected]
George School, Newtown, PA
The BX-24 microcontroller
• The BX-24 is a 24-pin
microcontroller made by
NetMedia
• Small and Fast
• Floating-point math
• 16 I/O pins (8 built-in
A-to-D converters)
• EEPROM storage
• About $45
• Programmed with BasicX, a high-level language
compatible with Visual Basic. BasicX is free.
Exciting Technology
The BX-24 can be used to:
• Autonomously control nearly any mechanical device
such as robots, vehicles, airplanes, vacuum
cleaners, etc.
• Output electrical signals to (thereby controlling)
motors, speakers, LCD panels, lights, LEDs, etc.
• Read data such as temperature, light intensity,
magnetic field strength, force, distance, flame (IR),
conductivity, etc.
• Record data in space, underwater, your back yard
Personal Computer vs BX-24
The PC:
• Is faster
• Has more computing power
• Is larger, heavier and therefore more stationary
• Is more expensive
• Is dependent on AC power
• Is better suited for gaming and desktop
programming
Why BX-24?
The BX24:
• Is smaller and therefore transportable
• Is cheaper
• Has no moving parts: data a programs are burned in
to the chip. Can be removed from power
• Runs on a 9V battery
• Is better suited for remote and mobile applications
• Students love it!
The Robodyssey Motherboard
• Robodyssey Systems in
Trenton, NJ designed and
sells the RAMB
• Makes programming the
BX-24 easy
• About $45
• Could do it yourself:
Wheeled Robots (My
students use the Mouse)
Expressive Robots
(ESRA)
Walking Robots
Kits
Just Toys?
•
•
•
•
•
Fun but not a toy
Learn a real computer language
Learn logic skills
Learn electronics
Research universities are now using the BX-24 to
teach computer science
• Microcontrollers allow the average person to do
what only NASA could do just a few years ago
• Springboards into other “serious” fields such as
electronics, aerospace engineering, manufacturing,
automotive and medical applications, etc.
“Computers never do what
you want them to do, only
what you tell them to do.”
Brian Patton
Vice President, Robodyssey Systems
BasicX and Robotics
• Textbook written for novices and
beginners ages 12 and up
(especially for high school and
college)
• Only one of its kind
• A teacher by your side to walk you
through material
• Over 300 problems and 400 full
color images. 365 pages.
• A complete curriculum
• $44.95 textbook
• Who has it?
A Quick Tutorial
• Rather than just a Show-and-Tell,
let me explain some of the basics
of computer and microcontroller
programming
• Very abbreviated tour of the book
• Let’s start by learning how the BX24 outputs data…
Creating a Program
• The program is written on the PC
in the BasicX language
• BasicX can be downloaded for free
at www.basicx.com
• The code is saved as a simple text
file. (New programs start with a
blank page.)
• When the program is ready to run,
simply press one button to compile
the program into a language the
BX-24 can understand
• The compiled program is sent to
the BX-24 via a serial cable
OUTPUT:
Printing data to the PC
Let’s write a short program that
will display a simple message to
the computer screen. The text
message will be sent back to the
PC via the serial cable. Here’s
the code:
Debug.Print "Hello, my name is Chris."
OUTPUT:
Printing data to the PC
Here’s what the program’s output looks like on the
PC’s monitor:
OUTPUT:
Printing data to the LCD
With a small LCD screen, we can print messages
and data without the need of a computer monitor.
This allows us to be mobile! The code to do this is
easy, too:
Call InitLCD
Call Display2Line("Hello", "My name is Chris")
OUTPUT:
Printing data to the LCD
Here’s what the program’s output looks like on the
LCD screen:
Loops
• Almost all computer problems use
structures called “loops” to
repeatedly perform a task or
tasks.
• Do-Loops can run forever.
• For-to-Next loops run for a finite
number of times.
Do-Loops
Do
Debug.Print "I can't stop!!!"
Loop
For-To-Next Loops
Dim i as Integer
Debug.Print "I can count fast!"
For i = 1 to 5
Debug.Print CStr(i)
Next
Delays
Sometimes, the computer performs
its tasks too quickly. We can use a
Delay command to slow it down:
Dim i as Integer
Debug.Print "Countdown...."
For i = 5 to 1 Step -1
Debug.Print CStr(i)
Call Delay(1.0)
Next
Debug.Print "Lift Off!"
Computer Logic
The computer can be programmed
to think using the “If-Then” logic
statement. Here’s how we humans
employ logic statements:
• First, check to see if the door is open.
• If the door is open, then walk right
through.
• Else (computerese for “otherwise”), if the
door is unlocked, then turn the handle and
walk through.
• Else, unlock the door with a key, turn the
handle, and walk through.
The computer
is only as smart
as the person
who
programmed it!
An If-Then Logic Statement
For i = 1 to 5
If (i <= 3) Then
Debug.Print "I am happy to be here!"
ElseIf (i = 4) Then
Debug.Print "BasicX rocks!"
Else
Debug.Print "Let's get started!"
End If
Next
OUTPUT Using PutPin
• BasicX has a command named PutPin that can
be used to turn on and off external devices such
as lights, LEDs, motors, buzzers, etc.
• All you have to do is tell the BX-24 which pin the
device is connected to and whether to turn it on
or off:
Call PutPin(5, 1)
The device is
connected to pin 5
1 = Turn it ON
OUTPUT: Onboard LEDs
• The BX-24 has two built-in LEDs.
One red (pin 25), one green (pin 26).
• Think about how to make a light blink.
What we take for granted must be
painstakingly programmed into the
computer line by line:
Do
– Turn on the light
Call PutPin(26,1)
– Leave
for some time
Callit on
Delay(0.3)
– Turn
off the
light
Call
PutPin(26,0)
– Leave
for some time
Callit off
Delay(0.3)
– Repeat
Loop
OUTPUT: External LEDs
• External LED’s can also be easily controlled with
the BX-24 using the PutPin command. (Here,
the LED is connected to pin 5.)
• This code simulates a flickering candle by using
random delay times between 0.0s and 0.1s:
Do
Call
Call
Call
Call
Loop
PutPin(5,1)
Delay(Rnd * 0.1)
PutPin(5,0)
Delay(Rnd * 0.1)
OUTPUT: Piezo Buzzers
• Loud, obnoxious buzzers can
also be controlled with the BX-24
• A class of buzzers can be driven
by simply connecting them to a
battery
• Connect and disconnect the
battery (loops!) and you can turn
the buzzer into a siren
• Use the PutPin command to turn
the buzzer on and off
OUTPUT: Speakers
• The BX-24 can also control
speakers and audio transducers
• These devices cannot simply be
connected to a battery. They
must be turned on and off to
make a sound.
• There are two more commands
that can be used to turn the
output voltage on and off: the
PulseOut and FreqOut
commands.
OUTPUT Using PulseOut
Duration = 0.5s
Dim i as Integer
For i = 1 to 100
Call PulseOut(12, 0.500, 1)
Call PulseOut(12, 0.001, 0)
Next
1 = Turn it ON
0 = Turn it OFF
The speaker is
connected to pin 12
Duration = 0.001s
OUTPUT Using FreqOut
Musical notes have a particular
frequency. Using the FreqOut
command, the BX-24 can
output these frequencies to a
speaker.
The speaker is
connected to pin 12
Duration = 2s
Call FreqOut(12, 512, 0, 2.0)
Frequency #1 = 512 Hz
Frequency #2 = 0 Hz
Robot Music
The BX-24 can be programmed
to play familiar tunes.
Or build your own piano and make the music yourself.
Beats
When two notes of similar
frequencies are added
together, a beat is created.
From Section 9.3 in BasicX and Robotics
The speaker is
connected to pin 12
Duration = 5s
Call FreqOut(12, 512, 514, 5.0)
Frequency #1 = 512 Hz
Frequency #2 = 514 Hz
Here, the beat frequency is 2Hz. (514Hz – 512Hz = 2Hz)
OUTPUT: Servomotors
• Electric motors spin when a voltage is applied to it.
• Servomotors (or servos) are special motors
commonly used in R/C planes, cars, and boats.
Roboticists also use them.
OUTPUT: Servomotors
•
•
•
•
Servos are controlled with the PulseOut command.
A 1-ms pulse turns the servo clockwise
A 2-ms rotates it counterclockwise
The speed can be controlled with pulse width
modulation (PWM)
OUTPUT: Grippers
• Grippers use servo motors to
open and close their jaws
• Loops and the PulseOut
command is used to control its
movement
• To hold an object, the jaws
must continually be pulsed
INPUT: Voltmeter
• Not only can the BX-24 output voltages, it can
read them, too
• This is easy to do with the GetADC command
• The analog voltage from a battery, for example,
must be converted into a digital signal before it
can be read by the computer
• The BX-24 has eight built-in A-to-D converters!
• Digital signal 0 = 0V
• Digital Signal 1023 = 5V (10-bit value)
• Therefore, a signal of 512 is
~2.5V. What does a AA battery
read?
INPUT: Light meter
• Ambient light can be read
using GetADC and an
inexpensive photoresistor
• As the light intensity
increases, its resistance
drops and the voltage to the
BX-24 increases
• This signal can be put to
music with the FreqOut
command
• Some “light” music anyone?
Light Meter Data
A night watchman was “observed” checking the classroom.
From Section 17.4 in BasicX and Robotics
INPUT: Infrared Range Finder
• The range (or distance) to any
object can be determined using
GetADC and an IR sensor
• A transmitter sends out an invisible
(to the human eye) beam of
infrared light
• The amount of light picked up by
the receiver is an indication of the
distance to the object
• Section 16.9 in my book shows
how to convert the digital signal to
an actual range
• Have you seen these? Yes!
INPUT: Temperature Sensor
• The ambient temperature be
determined using GetADC and
an inexpensive thermistor
• As the temperature increases,
the thermistor’s resistance
increases and the voltage to
the BX-24 decreases
• The temperature can be
calibrated and displayed in
Fahrenheit, Celsius, and Kelvin
scales. (See Section 17.7 of my book.)
INPUT: Flame Sensor
• Raw infrared light (heat) can be
measured and displayed using
an infrared transistor and the
GetADC command
• This sensor is also used in linefollowing robots and soccerplaying robots
• What light/heat sources are
detected?
It can be rocket science!
• In 2003, NASA, Penn State, and Clemson
University launched a Terrier-Orion rocket
from Wallops Island, Virginia. The rocket,
part of the SPIRT II campaign, was in space
for about 10 minutes and experienced nearly
20-G’s during liftoff.
SPIRIT II Results
• High school students (at
George School) in my physics
and computer science classes
designed an experiment that
flew onboard that rocket.
• A BX-24 and RAMB
motherboard were used to
measure the forces of liftoff and
any changes in temperature
within the payload.
• The experiment cost less than
$100 (the force sensors cost 4¢
each) and returned excellent
data.
Robots in Action
Let’s take a look at a few robots and how they utilize these
basic microcontroller principles. Each robot is controlled
by the BX-24. Can you picture how the commands are
put together to obtain these results?
•
Follow Me
•
– Used in psychological research
labs across the country including
Yale
– Autistic research in high school?
– Not so smart
•
Line Following Mouse
– A bit smarter, but still constrained
•
Battle Bot Hack
– H-bridge technology
•
The Crawler
– Another H-Bridge application
– Stays on tabletop
ESRA Expressive robot
•
Robot Soccer Junior
– 2050 Challenge
•
Clean Sweep
– Smart and useful (sort-of)
•
RoboSapien Hack
– Brain surgery
Future Work
This is only the beginning. In the field of robotics, we are
(now) limited only by our imaginations. Here are some
other applications that my students are interested in
and/or working on:
• Inner planetary exploration especially on the Moon
and Mars
• More rocket launches
• Balloon research
• Salt run-off experiment
• A DIY science classroom laboratory
• DARPA Challenge
– 2015 (1/3 of all military vehicles must be
autonomous)
• Understanding robotics to make intelligent, ethical
decisions
Thank you for coming!
If you would like to receive updates on what is happening with
my students and our robots, please enter your name and email
address in my notebook.
Also, if you would like to purchase my book, the
cost is $44.95. Please make the check out to
Robodyssey. I would be delighted to sign it for you.
www.basicxandrobotics.com
[email protected]
Thank you for coming!
If you would like to receive updates on what is happening with
my students and our robots, please enter your name and email
address in my notebook.
Also, if you would like to purchase my book, the
cost is $44.95. Please make the check out to
Robodyssey. I would be delighted to sign it for you.
www.basicxandrobotics.com
[email protected]
Follow Me
[to be added at a later time]
This simple robot application is a fairly unintelligent one.
The Mouse, equipped with an infrared range-finding
sensor, will continually spin around until something comes
close to it. Then, the robot will move toward the object,
stopping just prior to hitting it. If the object is removed, the
process is repeated.
Can you imagine which commands and logic structures
are used for this application? What would the If-Then
statement look like?