The goal of this example is to demonstrate how to use joystick axes to control the cursor using a Virtual Mouse. This assumes that the reader is familiar with the basics of creating Building Blocks as shown in the Detailed Tutorial.
This example will use the mini-joystick on the CH Products CH Pro Throttle USB to control a virtual mouse.
The first step is to create a new virtual mouse.
Right-click in the list of Programming Items and select Create Virtual Device ‣ Virtual Mouse.
The default settings for the new virtual mouse will be sufficient for this example.
The next task is to use the values from the mini-joystick on the CH Pro Throttle USB to create values for the axes on the virtual mouse.
Create Axis building blocks for the X-Axis and Y-Axis on the CH Pro Throttle USB.
Connect an Axis Calibration building block to each Axis building block.
Move the mini-joystick on the CH Pro Throttle USB to determine the minimum and maximum values that its axes generate. Set the Min and Max values of each Axis Calibration block's Expected input range values that the attached axis generates.
Set the Min and Max values of the Calibrated output range to "–5" and "5" respectively.
Set the Center Value of each Axis Calibration block to the value that each axis generates "0" when it is not being pushed.
Adjust the Deadband value of each Axis Calibration block to set the distance that the mini-joystick needs to move before the output of the block changes from "0" to another value. This is the point at which the cursor will start moving on the screen when the virtual mouse axes are connected to the Axis Calibration blocks. A joystick that has a firm feel and a repeatable center value can use a smaller deadband value. A joystick that has a loose feel will likely need a larger deadband value.
At this point, let the mini-joystick return to its center point and verify that the output values of the Axis Calibration building blocks are both "0". If the blocks have any other output value, the cursor will move on the screen when the virtual mouse is attached. In the worst case, the cursor could be uncontrollable.
If the output value of either Axis Calibration block is not "0" when the joystick is centered, double-check the settings of the Axis Calibration blocks as described above before connecting the virtual mouse.
The next step is to connect the virtual mouse to the Axis Calibration building blocks.
Create Virtual Axis building blocks for the X-Axis and Y-Axis on the virtual mouse and connect them to the corresponding Axis Calibration building block.
At this point, moving the mini-joystick on the CH Pro Throttle USB should cause the cursor to move on the screen. Just as importantly, when the mini-joystick is released, the cursor should stop moving.
If the cursor is too slow or too fast when the mini-joystick is pushed, then the speed of the cursor can be adjusted using two methods. The first speed adjustment is to change the values produced by the Axis Calibration building blocks:
The second speed adjustment is to use a Driver Configuration with a custom mouse acceleration curve:
In addition to controlling the cursor with the mini-joystick, the CH Pro Throttle USB can also be configured to trigger buttons on the virtual mouse.
Create Button building blocks for two of the buttons on the CH Pro Throttle USB.
Connect Virtual Button building blocks for Button #1 and Button #2 on the virtual mouse.
At this point, the CH Pro Throttle USB can be used to control the axes and buttons of the virtual mouse.