= Tutorial 5: Advanced remote control usage =

== Introduction ==

As we've seen in [[Tutorial1FirstRobot|tutorial 1]], we created a '''{{{Gamepad}}}''' class in order to control our robot. This class inherits from '''{{{RemoteControl}}}''', and implements a few virtual methods:

{{{
#!python

class Gamepad(RemoteControl):
    def _createFrontend(self):
        return Thrustmaster(settings.THRUSTMASTER_PATH)

    def _buildComponents(self):
        self._addConfig("walk")
        self._addConfig("body")

        self._addComponent(Button, command=self.selectNextConfig, key="button_008", trigger="hold")
        self._addComponent(Button, command=self.selectPreviousConfig, key="button_009", trigger="hold")

        self._addComponent(Button, command=self.robot.incBodyPosition, key="button_004", mapper=MapperSetValue(dz=+5))
        self._addComponent(Button, command=self.robot.incBodyPosition, key="button_005", mapper=MapperSetValue(dz=-5))
        self._addComponent(Joystick, configs="walk", command=GaitSequencer().walk, keys=("analog_02", "analog_03", "analog_00"), mapper=MapperWalk())

        self._addComponent(Analog, configs="body", command=self.robot.setBodyExtraPosition, key="analog_00", mapper=MapperSetMultiply('yaw', coef=-15))
        self._addComponent(Analog, configs="body", command=self.robot.setBodyExtraPosition, key="analog_03", mapper=MapperSetMultiply('pitch', coef=-15))
        self._addComponent(Analog, configs="body", command=self.robot.setBodyExtraPosition, key="analog_02", mapper=MapperSetMultiply('roll', coef=15))
}}}

The first method, '''{{{_createFrontend()}}}''' must return a valid frontend (we just saw in [[Tutorial4AddInputFrontendSupport|previous tutorial]] how to create such frontends). This methods takes as first argument the frontend path in '''{{{/dev}}}'''. An additional argument can be given to override the '''{{{DEFAULT_AXIS_CALIBRATION}}}''' table.

The second method, '''{{{_buildComponents()}}}''' is where interesting things take place. Here, we create the buttons/axis mapping to the robot controls.

== Components ==

'''Py4bot''' implements different components to build a custom remote control mapping:

=== '''{{{Button}}}''' ===

This is a simple push button, whith several ''triggers'', in order to control its behavior:

 * click
 * double-click
 * press
 * release
 * hold
 * double-hold

Default trigger is ''click'' (you must press and release the button quickly).

=== '''{{{Switch}}}''' ===

This is a button toggling between 2 states when you press it.

=== '''{{{Analog}}}''' ===

This component handles a single analog axis.

=== '''{{{Joystick}}}''' ===

Combines several '''{{{Analog}}}''' axis.

== Configurations and modifiers ==

There are many commands to control the robot, and not enough physical buttons/axis on a gamepad. So, a solution is to multiplex these buttons/axis. There are 2 ways to do that: ''configurations'' and ''modifiers''. ''configurations'' allow us to change the entire mapping; ''modifiers'' only changes a button meaning.

To create several ''configurations'', we use the '''{{{_addConfig()}}}''' method. This method take a string as argument, the name of the config. In our example, we created 2 ''configurations'', one to dynamically control the robot (make it walk), the other one to statically control the robot (move the body).