Joystick and Throttle box USB InterfaceA long while ago I created a Yoke and Rudder peddals for flying with flightsims. Check this page. 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. |
Yoke and Rudder ControlThe 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 ControlThe Throttle box has a separate USB interface situated within the box. The buttons are used for various settings, some double. |
Main DrawingFor reference, you can see the connections to the microcontroller. All arrows upward are connected to the +5V. The hatswitch is drawn with diodes but the combining of inputs is done by the firmware. |
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RudderThe 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.
MicrocontrollerBoth 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?
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The VIEW ControlThe View box is a very minimal joystick, only 8 buttons. It consits of a smaller USB chip, the PIC18F14K50. |
The FirmwareFor 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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