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Unread 17-03-2015, 22:36
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Blake B
AKA: Blake
FRC #4909 (The Bionics)
Team Role: Mentor
 
Join Date: Mar 2009
Rookie Year: 2007
Location: Massachusetts
Posts: 89
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Trouble with serial port: HAL - VISA: Resource Not Found

Greetings, we hare having trouble using our NavX MXP via its USB connection.

We have our NavX connected using a USB cable as described:
https://code.google.com/p/navxmxp/wi..._via_USB_cable

When running the sample code https://code.google.com/p/navxmxp/so...eRobotExample/

We get the following exception:

Code:
ERROR Unhandled exception: java.lang.NullPointerException at [
org.usfirst.frc.team2465.robot.Robot.operatorControl(Robot.java:93), 
edu.wpi.first.wpilibj.SampleRobot.startCompetition(SampleRobot.java:148), 
edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:234)]
The error appears to be referring to the first use of the imu object.
Code:
boolean is_calibrating = imu.isCalibrating();
Further investigation reveals that the SerialPort may be the culprit.
We moved the following line of code into the robotInit method yields a more descriptive error:

(Robot.java:81)
Code:
SerialPort my_serial_port = new SerialPort(57600,SerialPort.Port.kUSB);
Code:
ERROR Unhandled exception: java.lang.RuntimeException:  Code: -1073807343. HAL - VISA: Resource Not Found at [
edu.wpi.first.wpilibj.hal.HALUtil.checkStatus(HALUtil.java:48), 
edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:198), 
edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:251), 
org.usfirst.frc.team2465.robot.Robot.robotInit(Robot.java:81), 
edu.wpi.first.wpilibj.SampleRobot.startCompetition(SampleRobot.java:121), 
edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:234)]
Any Ideas?
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Blake
Electrical, Programming and Design

Creator FRC Q&A 2017
Mass FRC Team 4909: The Bionics
Maine FRC Team 5122: The RobOTies (2014-2015)
Maine FRC Team 2648: Infinite Loop (2008-2011)
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