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Unread 21-03-2015, 14:49
L1TH1UM L1TH1UM is offline
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Team Role: Programmer
 
Join Date: Mar 2015
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Preferences table Null Pointer Exception

Hello,

We are having some issues using the preferences table utility on SmartDashboard. We are supposed to be getting a table from which we can edit robot preferences such as potentiometer setpoints and encoder setpoints.

However, when we run the code it throws a Null Pointer Exception because we declared the preferences varable (Preferences prefs but we didn't create and object and we are trying to use an operator (prefs.getDouble). Using "prefs = new Preferences();" does not work, and there's nothing on the wpilibj documentation that tells us how to fix this (create an object for preferences).

Here's the page we're referencing: https://wpilib.screenstepslive.com/s...smartdashboard

Our code is almost exactly the same as that just minor differences such as names and values. We are programming in Java.

Any help would be appreciated, thanks.