Serial Data to RoboRio (Hello World)

Technical Java
1

I’m Just Trying to get a Hello World program to work over Serial communications.
I have yet to find the smoking gun to answer how to get the RS-232 port working. As soon as I put this line into the robot program stops working. This IS the only line of code currently entered.

SerialPort camdata = new SerialPort(115200, SerialPort.Port.kOnboard);

Console output:

ERROR: Could not instantiate robot org.usfirst.frc.team3244.robot.Robot! 
 Error at edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:218): ERROR Unhandled exception instantiating robot org.usfirst.frc.team3244.robot.Robot java.lang.RuntimeException:  Code: -1073807246. HAL - VISA: Resource Busy at [edu.wpi.first.wpilibj.hal.SerialPortJNI.serialInitializePort(Native Method), edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:112), edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:160), org.usfirst.frc.team3244.robot.Robot.<init>(Robot.java:12), sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method), sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62), sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45), java.lang.reflect.Constructor.newInstance(Constructor.java:408), java.lang.Class.newInstance(Class.java:433), edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:216)] 
 ERROR: Could not instantiate robot org.usfirst.frc.team3244.robot.Robot! 
ERROR  1  ERROR Unhandled exception instantiating robot org.usfirst.frc.team3244.robot.Robot java.lang.RuntimeException:  Code: -1073807246. HAL - VISA: Resource Busy at [edu.wpi.first.wpilibj.hal.SerialPortJNI.serialInitializePort(Native Method), edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:112), edu.wpi.first.wpilibj.SerialPort.<init>(SerialPort.java:160), org.usfirst.frc.team3244.robot.Robot.<init>(Robot.java:12), sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method), sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62), sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45), java.lang.reflect.Constructor.newInstance(Constructor.java:408), java.lang.Class.newInstance(Class.java:433), edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:216)]  edu.wpi.first.wpilibj.RobotBase.main(RobotBase.java:218)
2

I got Hello word using

SerialPort camdata = new SerialPort(115200, SerialPort.Port.kMXP);

Is the Onboard not available at boot?

3

Have you turned off Console Out?

4

No I haven’t came across that solution. How Do I do that?

I believe I also discovered that the USB# when trying to use one of them must have a device plugged in or the code will crash.

5

See Startup Settings here: wpilib.screenstepslive.com/s/currentCS/m/cs_hardware/l/262266-roborio-webdashboard

6

Well there it is

Enable Console Out - This enables the on-board RS232 port to be used as a Console output. It is recommended to leave this enabled unless you are using this port to talk to a serial device (note that this port uses RS232 levels and and should not be connected to many microcontrollers which use TTL levels).

Don’t use this port it tells me.