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Problem with NXT tutorial

asked 2012-04-25 04:48:03 -0500

updated 2014-01-28 17:12:06 -0500

ngrennan gravatar image

Hi, I'm trying to follow this tutorial but when I launch the program I get this warning:

[INFO] [WallTime: 1335361633.048001] Creating ultrasonic with name 
  ultrasonic_sensor on PORT_2
[WARN] [WallTime: 1335361633.284565] caught an exception nxt.error.DirProtError

My yaml file has this characteristics:

- type: ultrasonic
  frame_id: r_ultrasonic_link
  name: ultrasonic_sensor
  port: PORT_2
  spread_angle: 0.2
  min_range: 0.01
  max_range: 2.5
  desired_frequency: 10.0

Supposedly, these lines creates an ultrasonic sensor with a spread angle of 0.2m, a min range of 0.01m, and a max range of 2.5m that is connected to PORT_2.

I only has this problem with the ultrasonic sensor. Touch and color (intensity) sensors work fine. I have the correct firmware (v1.28).

EDIT: I've listed the topics:

$ rostopic list

But when I try to see the topic I get this warning.

$ rostopic echo /ultrasonic_sensor
WARNING: topic [/ul/ultrasonic_sensor] does not appear to be published yet

Thanks in advantage for your help.


Raúl Pérula

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answered 2012-05-21 00:12:11 -0500

I can't solve the warning, but seems like works.

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Asked: 2012-04-25 04:48:03 -0500

Seen: 387 times

Last updated: Jan 28 '14