Package ve.ucv.ciens.icaro.libnxtarcontrol

This package contains a wrapper library and reference implementation of the NxtAR robot control protocol for the LejOS operating system.

See: Description

Interface Summary

Interface	Description
UserActionListener	An object to be notified when an user action has been received in a protocol message.

Class Summary

Class	Description
DecodedControlAction	An immutable and pure data class that represents an action decoded from a protocol data message.
NxtARControlProtocol	A wrapper around the NxtAR robot control protocol for the LejOS operating system.

Enum Summary

Enum	Description
DecodedControlAction.Action	All recognized actions.
DecodedControlAction.Motor	All motor ports and possible combinations without repetitions.

Package ve.ucv.ciens.icaro.libnxtarcontrol Description

This package contains a wrapper library and reference implementation of the NxtAR robot control protocol for the LejOS operating system.

The protocol is based on 2 byte long data messages that encode a set of motor ports, actions on those motors and the speed of the motors. The first byte encodes a set actions and motors, while the second byte contains an integer number representing the speed to set to the enabled motors. The first byte's bits encode the following data (from least significant to most significant bit):

• Motor port A enabled.
• Motor port B enabled.
• Motor port C enabled.
• Direction of movement. 0 for backward movement, 1 for forward movement.
• Request to return the enabled motors to their initial positions.
• Customizable user action 1.
• Customizable user action 2.
• Customizable user action 3.

This bits are decoded using the binary masks defined in NxtARControlProtocol. This mechanism allows to set the state or execute an action on multiple motors simultaneously. The user actions are executed using callback objects registered with the aforementioned class.

The NxtARControlProtocol class includes methods to read, decode and execute a protocol message, independently of how those messages are generated. An example would be messages read from a Bluetooth or USB stream, as well as messages generated by the application that is using the library.