Introduction to Robotics/Control Flow/Lecture/Teachers - Revision history

wikademia>Dr. Eme: moved Beta:Introduction to Robotics/Control Flow/Lecture/Teachers to Introduction to Robotics/Control Flow/Lecture/Teachers over redirect

2009-08-12T19:24:47Z

moved Beta:Introduction to Robotics/Control Flow/Lecture/Teachers to Introduction to Robotics/Control Flow/Lecture/Teachers over redirect

← Older revision	Revision as of 19:24, 12 August 2009
(No difference)

wikademia>Wikademia: moved Introduction to Robotics/Control Flow/Lecture/Teachers to Beta:Introduction to Robotics/Control Flow/Lecture/Teachers

2009-06-05T16:59:19Z

moved Introduction to Robotics/Control Flow/Lecture/Teachers to Beta:Introduction to Robotics/Control Flow/Lecture/Teachers

← Older revision	Revision as of 16:59, 5 June 2009
(No difference)

wikademia>Wikademia at 19:17, 10 April 2009

2009-04-10T19:17:44Z

← Older revision		Revision as of 19:17, 10 April 2009
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	{{~~Introduction to Robotics/Nav\|Control Flow~~}}		{{ntnes}}

	== Control Flow ==		== Control Flow ==

wikademia>Wikademia: 6 revisions

2009-04-10T18:34:04Z

6 revisions

← Older revision	Revision as of 18:34, 10 April 2009
(No difference)

wikademia>Whiteknight: /* How it Works */

2007-08-06T19:43:16Z

How it Works

← Older revision		Revision as of 19:43, 6 August 2007
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	#If the counter variable is not equal to the TO value, go to #2		#If the counter variable is not equal to the TO value, go to #2

	{{Introduction to Robotics/Visual\|~~image=[Insert Image of how a loop works here]\|caption=How a~~ FOR / NEXT ~~Loop Works.~~}}		{{Introduction to Robotics/Visual\|FOR NEXT Control Flow}}

	== Labels and GOTO ==		== Labels and GOTO ==

wikademia>Whiteknight: /* Labels and GOTO */

2007-08-06T19:42:53Z

Labels and GOTO

← Older revision		Revision as of 19:42, 6 August 2007
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	Labels are like destination points. When we put a label in our code, we can jump to it using a GOTO statement.		Labels are like destination points. When we put a label in our code, we can jump to it using a GOTO statement.

	{{Introduction to Robotics/Visual\|		{{Introduction to Robotics/Visual\|Labels and GOTO}}
	~~[Insert an image here~~
	}}

	== Branches ==		== Branches ==

wikademia>Whiteknight: /* FOR / NEXT Loops */

2007-08-06T19:40:32Z

FOR / NEXT Loops

← Older revision		Revision as of 19:40, 6 August 2007
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	We can “nest” FOR / NEXT loops. “nesting” means that we put one loop inside another loop. When we nest FOR / NEXT loops, we need to use different counter-variables for each loop.		We can “nest” FOR / NEXT loops. “nesting” means that we put one loop inside another loop. When we nest FOR / NEXT loops, we need to use different counter-variables for each loop.

	{{Introduction to Robotics/Visual\|~~text=~~		{{Introduction to Robotics/Visual\|Nested Loops 1}}
	~~MyCount1 VAR Byte~~
	~~MyCount2 VAR Byte~~

	~~FOR MyCount1 = 0 TO 200~~
	~~FOR MyCount2 = 0 TO 200~~
	~~...~~
	~~NEXT~~
	~~NEXT~~
	}}

	If we use the same counter-variable, the variable will be changing in the inner loop, and the outer loop will not work correctly:		If we use the same counter-variable, the variable will be changing in the inner loop, and the outer loop will not work correctly:

wikademia>Whiteknight: /* FOR / NEXT Loops */

2007-08-06T19:38:43Z

FOR / NEXT Loops

← Older revision		Revision as of 19:38, 6 August 2007
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	If we use the same counter-variable, the variable will be changing in the inner loop, and the outer loop will not work correctly:		If we use the same counter-variable, the variable will be changing in the inner loop, and the outer loop will not work correctly:

	{{Introduction to Robotics/Visual\|~~text=~~		{{Introduction to Robotics/Visual\|Nested Loops}}
	~~MyCount VAR Byte~~

	~~FOR MyCount = 0 TO 200~~
	~~FOR MyCount = 0 TO 50~~
	~~...~~
	~~NEXT~~
	~~NEXT~~

	~~MyCount never reaches 200~~
	}}

	=== How it Works ===		=== How it Works ===

wikademia>Whiteknight: /* FOR / NEXT Loops */

2007-08-06T19:37:01Z

FOR / NEXT Loops

← Older revision		Revision as of 19:37, 6 August 2007
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	We have already seen the FOR / NEXT loop in the previous lab, but what does it do? A FOR / NEXT loop uses a counter variable to count the number of loops. Each time we perform the loop, we increase the value of the counter variable. The NEXT keyword moves the control flow back to the top of the loop. If your loop does not have a NEXT keyword, it will not repeat. Once the counter variable reaches the TO value, the loop exits, and the control flow continues after the loop.		We have already seen the FOR / NEXT loop in the previous lab, but what does it do? A FOR / NEXT loop uses a counter variable to count the number of loops. Each time we perform the loop, we increase the value of the counter variable. The NEXT keyword moves the control flow back to the top of the loop. If your loop does not have a NEXT keyword, it will not repeat. Once the counter variable reaches the TO value, the loop exits, and the control flow continues after the loop.

	{{Introduction to Robotics/Visual\|~~image=[Insert Image of a loop with arrows going up to the top, and out from the bottom]\|caption=A~~ FOR / NEXT Loop.}}		{{Introduction to Robotics/Visual\|FOR NEXT Loop}}

	We can “nest” FOR / NEXT loops. “nesting” means that we put one loop inside another loop. When we nest FOR / NEXT loops, we need to use different counter-variables for each loop.		We can “nest” FOR / NEXT loops. “nesting” means that we put one loop inside another loop. When we nest FOR / NEXT loops, we need to use different counter-variables for each loop.

wikademia>Whiteknight: New page: {{Introduction to Robotics/Nav|Control Flow}} == Control Flow == A computer can only perform one instruction at a time. In a program, we write the instructions that we want the computer ...

2007-07-19T22:00:43Z

New page: {{Introduction to Robotics/Nav|Control Flow}} == Control Flow == A computer can only perform one instruction at a time. In a program, we write the instructions that we want the computer ...

New page

{{Introduction to Robotics/Nav|Control Flow}}

== Control Flow ==

A computer can only perform one instruction at a time. In a program, we write the instructions that we want the computer to perform, starting at the top of the page. The processor reads each instruction at a time and performs that action before moving down to the next instruction. The order in which instructions are performed is known as the '''control flow''' of a program. The regular control flow of a program is from the top of the code to the bottom. However, there are several tools we can use to change the control flow, so that the robot can do more complicated things. An example of this is the FOR / NEXT loops that we saw in the first lab. A FOR / NEXT loop allows us to move the control flow back to the top of a block of code, so that we can repeat it multiple times. There are other control flow tools that we can use, such as '''nested loops''', '''branches''', and '''subroutines'''.

== FOR / NEXT Loops ==

We have already seen the FOR / NEXT loop in the previous lab, but what does it do? A FOR / NEXT loop uses a counter variable to count the number of loops. Each time we perform the loop, we increase the value of the counter variable. The NEXT keyword moves the control flow back to the top of the loop. If your loop does not have a NEXT keyword, it will not repeat. Once the counter variable reaches the TO value, the loop exits, and the control flow continues after the loop.

{{Introduction to Robotics/Visual|image=[Insert Image of a loop with arrows going up to the top, and out from the bottom]|caption=A FOR / NEXT Loop.}}

We can “nest” FOR / NEXT loops. “nesting” means that we put one loop inside another loop. When we nest FOR / NEXT loops, we need to use different counter-variables for each loop.

{{Introduction to Robotics/Visual|text=
MyCount1 VAR Byte
MyCount2 VAR Byte

FOR MyCount1 = 0 TO 200
FOR MyCount2 = 0 TO 200
...
NEXT
NEXT
}}

If we use the same counter-variable, the variable will be changing in the inner loop, and the outer loop will not work correctly:

{{Introduction to Robotics/Visual|text=
MyCount VAR Byte

FOR MyCount = 0 TO 200
FOR MyCount = 0 TO 50
...
NEXT
NEXT

MyCount never reaches 200
}}

=== How it Works ===

A FOR / NEXT loop does several things:

#Set the counter variable to the starting value.
#perform the instructions inside the loop.
#Increment the counter variable by 1.
#Check the counter variable. If it is equal to the TO value, the loop ends.
#If the counter variable is not equal to the TO value, go to #2

{{Introduction to Robotics/Visual|image=[Insert Image of how a loop works here]|caption=How a FOR / NEXT Loop Works.}}

== Labels and GOTO ==

Labels are like destination points. When we put a label in our code, we can jump to it using a GOTO statement.

{{Introduction to Robotics/Visual|
[Insert an image here
}}

== Branches ==

Computers can compare numbers together, to determine if they are equal, greater then, or less then. Using an IF / THEN, we can jump to different locations if the comparison is true. If the comparison is not true, then the IF / THEN does nothing, and the control flow moves to the next instruction.

== Subroutines ==

Subroutines allow us to reuse code so that we can avoid having to copy + paste things that need to be repeated.