Joystick and Throttle box USB Interface

A long while ago I created a Yoke and Rudder peddals for flying with flightsims. Check this page.
The interfaces used did have some limitations on axis and buttons.

Working with microcontrollers with USB capabilities gave me the idea to change my Flightsim Yoke and Rudder with a self made joystick interface. In this case, the need for 3 axis made me research the possibilities of using a Microchip PIC18F4550.

It would have limitations to the number of axis and buttons. But, where is that limit........

Well, with designing the throttle box, it was close, 8 axis and 8 buttons, total 9 bytes.

The joystick interface Yoke and Rudder should have at least 4 axis and 12 buttons and a hat switch?

In all cases, buttons and axis are freely configurable in all flightsims.

Joystick



Yoke and Rudder Control

The USB interface is situated in the control box (left).

Ailerons and Pitch is controlled by the Yoke. Rudder by the pedals and the thrust vector (X-Plane's Harrier and Osprey) is controlled on the control box.

The interface handles 5 bytes for analog inputs, and 24 bits ( 3 bytes) for buttons. These 8 bytes of information seem to be near the limit, at least for my system.....



 

Throttle Control

The Throttle box has a separate USB interface situated within the box.
8 Axis and 8 buttons is possible.
In my case, it controls four Throttles, Flaps, Mixture, Spoilers and Propellors.

The buttons are used for various settings, some double.

throttlebox

 

drawing

Main Drawing

For reference, you can see the connections to the microcontroller.
Click on the image for a better view.

All arrows upward are connected to the +5V.

The hatswitch is drawn with diodes but the combining of inputs is done by the firmware.
All potentiometers are 100k. All pull-up resistors are 4k7.

rudder

Rudder

The Rudder padals are seperated. This means that I needed to create a different way of sensoring the positions of the peddals.

Here you can see the connections.

Both potentiometers are 50k. A nice feature when you press both peddals down, the rudder is stil in the middle.

 

Microcontroller

Both interfaces are equipped with a bootloader. This makes programming by USB possible and is very easy to work with during debugging and testing. The bootloader is activated by a button while booting the microcontroller.

The firmware was originally written for PicBasic and is very short for both interfaces. Data values needs only to go out, right?

 



 

The VIEW Control

The View box is a very minimal joystick, only 8 buttons.
Using X-Plane with a second PC in Spot view mode, this View box is a handy tool to get the views in the right position.

It consits of a smaller USB chip, the PIC18F14K50.

viewbox

 

 

The Firmware

For those who would like to build a interface themsellfs, for a reference, the main files can be downloaded here as a package.

Questions or remarks? Send me a E-mail wih the link below the menu......

HAVE LOTS OF FUN

 

 

 


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