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Lesson 5
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5: Boe‐Bot M
r with BASIC itor program e
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is specified e electronic ox. ulse sign p a . ion and the rotational As you can s will vary lses there is g the Basic pulse durat value place 300 μs, or 1
NASA‐Threads Electricity and Magnetism Lesson 5: Boe‐Bot Motion
What if we wanted to change the speed of the motion? We would have to manipulate the pulse duration.
Duration Pulse idth
(ms) W Servo Action
650 1.3 Full Speed CW
700 1.4 ½ Speed CW
750 1.5 Stopped
800 1. 6 ½ Speed CCW
850 1. 7 Full Speed CCW
Hands On
Let’s look at this program that makes a Boe‐Bot move forward at full speed and then sharply turn left:
ut this program into your BASIC Stamp Editor and experiment with the duration and P
counter components of the program.
ow that you have a program that can move forward full speed and make a sharp left turn, ry to add to this program so that you make your Boe‐Bot reverse and turn sharply right. N
Solution:
NASA‐Threads Electricity and Magnetism Lesson 5: Boe‐Bot Motion
ow that you have the code written for full spe
urn, and sharp reuse
ha d to
of these a name and call on them accordingly as the flow N
t w
ed forward, full speed reverse, sharp right that code in other programs. For instance,
follow this flow chart:
This program requires multiple instances of full speed forward as well as full speed reverse. You could write the program to have the code for each motion of the Boe‐ Bot to be written each time it appears or
ou can use what is called a subroutine. written already
you do not have left turn, you may want to
t if you had a program that was suppose
Initialize Variables
(Defining the size of the variables used in the program)
y
Go Forward Full speed for a duration
Basically, if there is a code or a function in a program
f
to retype it every time it appears. You can simply call on it using a GOSUB command.
How do you use a GOSUB?
Well you give your prewritten code a name (i.e. for full speed forward, maybe its name should be fullForward). Once you have the name for the code, instead of writing that code into your program, you would type
GOSUB then the name of the code that you want to run (for forward it would be
GOSUB fullForward). Then you would type the rest of your code as you would like. You
can put as many GOSUB commands as you
want. Now whenever you need the code you can simply call on it. This is especially
Go in Reverse Full speed for a duration
Go Forward Full speed for a duration
Turn Sharply to the Right for a duration
Go in Reverse Full speed for a duration
helpful when something appears multiple times in a program. After you type out your full program with all the needed GOSUB commands below your program, you can paste the
Turn Sharply to the Left for a duration
code that the GOSUB is calling for (for full speed forward you would type fullForward: then all the code associated with full speed forward). Note that you put a colon after the name of
the code. Two things you should always remember when using the GOSUB command are:
. Put a RETURN statement on the last line of the subroutine. This tells the Boe‐Bot to go 1
back to the next line in the main program.
2. Put an END statement after your main program and before the first subroutine, so that the Boe‐Bot doesn’t plow on into the first subroutine after it finishes executing the main program.
de for full speed forward, full speed reverse, sharp right
Try it out! You already have the co urn, and sharp left turn. Give each
hart describes.
olution: t
c S
