NXT Program using Robolab 2.9.3

NXT Robolab 2.9.3 Investigator- Lesson 1

2007-12-19T20:45:00.001-08:00

Click to display the list of NXT Building Constructions as complied by Chang 2008

NXT_G Program Guides

NXT Robolab 2.9.3 on the use of Investigator
Main use is to collect data.
Activities are summarized at a glance sheets

Challenge No 1
To find the highest and lowest light readings in a room using investigator.
Write a program to record light sensor data once every second for 30 secs. Download the program to NXT

NXT Robolab 2.9.3 Lesson 10- Sample Programs

2007-12-18T23:52:00.000-08:00

Sample NXT Program using rotational sensor
Sample Program 1

Video Clip

NXT Robolab 2.9.3 Lesson 9 - Tips

2007-12-17T15:55:00.000-08:00

Can I change the display on the NXT during my ROBOLAB program?
Yes. With the Change View icon in the NXT Commands folder in ROBOLAB, you can change the display on the NXT. The display can be changed from its regular view to sensor values, motor speeds or the data log graph.

How can I make both motors move to an exact position, in sync?
To bring two motors to an exact angular location together, you should use the motor synch icon and the SMART rotational encoder. The program below accomplishes this.

How do I save multiple ROBOLAB programs on the NXT?
To save multiple ROBOLAB programs to the NXT, you need to use the Begin NXT icon instead of the normal Begin icon. The icon is found in the NXT Commands folder. When placed in your program the icon will have a pink box wired to it where you can write a name for your program. When you run your program it will download it to the NXT with the name you choose instead of the default program name, rbl.

How do I fill a container with a floating point decimal in Robolab 2.9?

To fill a container with a decimal value:

1. Drag a "Fill Container" block into your program.
2. Select the wiring tool, and right click on the "Set container to" node. A menu should appear.
3. Scroll down the menu and choose "Create" --> "Constant." A blue wire and blue constant box with a "1" in it should appear. If you try to type in a decimal, it will be truncated to an integer.
4. To change this, right click within the blue constant box. A menu should appear.
5. Scroll down the menu to "Representation." Another menu box should appear.
6. Select the "DBL" or "Double Precision" box.
7. The blue box and wire should become orange, to indicate floating point status. You should now be able to type in a decimal without its being truncated.

When I use the "stop" command in Robolab 2.9, the motors only coast to a stop. How can I command the NXT motors to stop on a dime?

In the initial version of Robolab 2.9, the stop comand does not work properly. The NXT motors coast to a stop rather than stopping abruptly.

There IS a way to program around this bug in Inventor so that the motors will stop abruptly without reversing direction:

1. Insert an "Optimize" function to set the motor to brake in between pulses. (You can also use Detective to set the motor pulse mode to brake.)
2. To stop a motor, instead of a stop command, insert a motor speed command and set the motor speed to zero.
3. If stopping a motor is your program's last command, insert a wait-for command of at least 200 msec immediately after setting the motor speed to zero. (You need to do this because the firmware commands the motors to float to a stop when the program ends.)

NXT Robolab 2.9.3 Lesson 8- motor synchronizing

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How does NXT motor synchronizing work in ROBOLAB?

To synch NXT motors in ROBOLAB, use the synchronize icon that looks like the icon below. Decide which motor you want to be the controller, and wire that into the controller port. Wire the other motor into the follower port.

To synchronize motors means to have them move in lock-step with each other. One motor is the controller (or driver), and one other motor is the follower. If you synchronize the two motors of a car, for example, the car will be much more likely to drive straight.

How can I make both motors move to an exact position, in sync?

To bring two motors to an exact angular location together, you should use the motor synch icon and the SMART rotational encoder. The program below accomplishes this.

The motor synch icon tells Motor B to follow whatever Motor A does. The motor power icon turns on Motor A (and thus Motor B, because it is following Motor A). The SMART rotational encoder controls Motor A's movement to the specified angular position. Motor B follows along, exactly in sync with Motor B.

Tips

Once you have synched two motors, they will only respond correctly to commands for the controller motor. For example, the writer of the program below synched motors A and B, programmed them to move together, and then tried to program them separately, forgetting that they were synched. The program below does not work correctly.

If you want to control the follower motor on its own again, you must turn off the synchronization. To do so, use the motor synch icon without any wires attached to it, as shown in the example below.

The following programs will not work

Sample NXT Robolab 2.9.3 on synchronizing motor
Program Sample 1

Video Clip

NXT Robolab 2.9.3 Lesson 7- Ultrasonic Sensor

2007-12-14T20:13:00.000-08:00

Use of Ultrasonic Sensor.
Wait for the sensor to detect an object within 30 cm by using the
Reverse Distance Icon. The default distance is 20 cm. One need to
use a modifier to change the distance.

Typical NXT Program using Robolab 2.9.3 for Reverse Distance Icon
This program waits for an object to approach within 30 cm of the sensor then it beeps five times

Typical NXT Program Sample 2
This program gets the robot to move forward within 30 cm from the wall then it beeps five times.

NXT Robolab 2.9.3 Lesson 6

2007-12-13T17:34:00.000-08:00

NXT Rotation Sensor
The NXT rotation sensor is built into the motor. It measures the rotation of motor in degrees, so one full rotation is equal to 360 degrees.
Use different methods to investigate how to stop the motor after one full rotation
First we use NXT Wait for Rotation
Second we use using the float output yellow stop sign
Third we use NXT wait for location icon. Unlike the wait for rotation icon we used before, wait for location does not reset itself to zero when it is called. We need to zero the sensor before we use the wait for location.
NXT Program using Robolab 2.9.3 on rotation sensor
Use NXT wait for rotation to stop the Motor A after one rotation 360 degrees. Use the red stop icon to stop the motor A.
Next wait for 2 seconds the restart the motor A. This time stop afer
one full rotation using Float Outputs yellow stop sign. Again wait for two seconds and then restart the motor A.
This time we use wait for location icon. Unlike the wait for rotation icon we need to zero when it is called.

First Method of Stopping Motor using rotation sensor of one full rotation

Second Method of stopping Motor using float icon

Third Method of stopping Motro using wait for location

Video Clip

NXT Robolab Inventor 4 -Lesson 5

2007-12-13T00:00:00.001-08:00

Use of Touch Sensor NXT sample program using Robolab 2.9.3

Use of Split Task NXT sample program using Robolab 2.9.3

NXT Robolab Inventor 4- Lesson 4

2007-12-12T21:51:00.000-08:00

Using NXT to trace a continuous black line

Program for single light sensor using Robolab 2.9.3 for NXT

Video Clip

NXT Robolab 2.9.3 Inventor 4 Lesson 3

2007-12-12T01:28:00.000-08:00

Wait for Distance 20 cm from the wall.
Program

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NXT Robolab 2.9.3 Inventor 4 Lesson 2

2007-12-12T00:14:00.000-08:00

Wait for Rotation
Motor A turns 720 degrees two complete turns
Program

Video Clip

NXT Robolab 2.9.3 Inventor 4 Lesson 1

2007-12-11T23:53:00.000-08:00

NXT Robolab 2.9.3 Inventor 4 Lesson 1
Program wait for dark using Light Sensor connected to port 2

Robot in Action

NXT Robolab 2.9.3 Pilot 4

2007-12-10T20:08:00.000-08:00

Pilot 4 is a notebook with one task on each page. In strong contrast to Pilot 3
where it had only one page but that page had two tasks on it.
Use the + and - buttons at the top to add or delete tasks ( notebook pages) and the red arrows
at the sides to switch between tasks.
Click on the watch, the touch sensor, and the light sensor icons. Their functions are different.
Light sensor is triggered by a specific light intensity rather than by a change of 5% as in Pilot 3.

Pilot 4 at a glance

Sample Program 1
Step 1
The Program starts with all motor off until touch sensor is pressed

Step 2
Motor A starts at power 1 and rotates at low speed until the touch sensor is pressed.

Step 3

Motor A switches to power 3 and rotates at medium speed until the touch sensor is pressed again.

Step 4
Motor A switches to power 5 and rotates at high speed until the touch sensor is pressed again. Because the program is in continuous mode, the program cycles back to step one and the motor shuts off.

NXT Robolab 2.9.3 Pilot 3

2007-12-07T21:44:00.000-08:00

Pilot 3 allows one to use all three outputs and to carry out two separate tasks.
For example the program turns on Port A motor in one direction of maximum power, the Port C motor in the opposite direction at half power, and a light connected to Port B. After 6 seconds the directions of the two motors reverse until touch sensor is pushed.
Please note a pink arrow has been added between the Print and Run buttons. This arrow lets one to select the Run mode. One arrow means run once and then stop. The icon with two arrows, called continuous mode means run the program over and over. If you downloaded the program in continuous mode, the motors would run fo six seconds, reverse until you pushed the touch sensor, reverse again for six seconds, reverse until you pushed the touch sensor, and so on.
There are two versons of continous mode. The first loops through the program forever. The second, with a number symbol in it, lets you specify how many times you want the program to repeat.
Examine the menu of the input options. There are icons to control motors using a light sensor as well as a touch sensor. The light sensor is triggered by a darkening of 5%.

Pilot 3 at a glance

Pilot 3 Sample Program 1
Motor A is on at the start when the room is light but the Motor A stops when the room gets darker

Pilot 3 Sample Program 2
Motor A & C runs forward for 2 seconds and reverse for 2 seconds forever

Figure 8
Video Clip

Sample on using Pilot 3
Video Clip

NXT Robolab 2.9.3 Pilot 2

2007-12-07T19:14:00.001-08:00

The second ROBOLAB program level is known as Pilot Two. It uses two output ports A and C. Click on one of the motor icons. In addition to the two motors and the light that you can see in Pilot One, there is now a stop sign. Choosing the stop sign will turn off the power to that port, so that a motor connected to it will not run and a light will not light. The numbers below the motors are the power settings. One is the lowest, and will cause the mtor to run slowly; five is the highest, and will make the motor turn at full speed.
Pilot 2 Lessons
Motors A and C to move forward until wait for Touch Icon to stop

Pilot 2 Test Program for NXT to Wait for Touch Icon

Pilot 2 Test Program for NXT to Wait for Release Icon

Video Clip on Pilot 2 for NXT

NXT Robolab 2.9.3 Lesson 1

2007-12-06T23:43:00.000-08:00

Tutorial one on using Robolab 2.9.3 for NXT
Using Inventor 4 level
Try to program a random beeper
-to beep 1,2,3 or 4 on very turn
To test an NXT start the program running and press the touch sensor.
Each time you press the sensor, one will hear a number of beeps.
For example the sequence 1332... would mean that the first time one pressed
the touch sensor, NXT beeped once, the second time it beeped three times,
the third time it also beeped three times, and the fourth time it
beeped twice.

First Example of Random Program using Inventor 4

Second Example of Random Program to generate a sequence 1,3,2,4

Pilot One for NXT
The simplest level of ROBOLAB 2.9.3 is called the Pilot 1. The program that appears on the screen when one open Pilot 1, turns the motor for four seconds then stops.
One can change the direction of the motor by clicking the picture of the motor. Three icons will pop up namely the original motor with an arrow pointing left, a second motor with an arrow pointing right, and a light. Select the motor with the arrow pointing right. Download the program and run it. The motor should turn in the opposite direction.
Pilot One at a Glance

Robolab 2.9 Menu

Video Clip NXT using Piolot One