Adding an H-Shifter To Your Wheel

**** THIS PAGE IS A WORK IN PROGRESS!!! ****

So, you've got a racing wheel and a nice set of pedals, but it just doesn't feel complete.  You've even got a sequential gear shift (Paddles or a separate shifter) but you still don't feel satisfied.  Wouldn't it be great to be able to chop from 5th down to 2nd directly, without shifting through 4th and 3rd first?  What you require is an H-Shifter, and these pages will show you how to make one, or how to adapt a commercial one to work with your current controls.

Design Considerations

There are 3 main problems in designing and implementing an H-Shifter.  They are:

1.    The Mechanics involved

2.    The Electronics involved

3.    Getting games to recognise and use it.

The first two problems are just basic design issues that can be easily solved given careful thought on how you want your shifter to feel and respond.  The third problem is the hardest to overcome, but can be solved by setting up your shifter in exactly the same way to the commercially available shifter.

The Act Labs RS Shifter

The RS Shifter from Act Labs is an 8 selection H-Shifter.  This allows for up to 7 forward gears and 1 reverse gear.  The shifter can also be used in Hi-Lo mode as a sequential shifter (Pushing forward to change down, pulling back to change up).  The RS Shifter is supported by many racing games, and thus is the ideal unit to base a homemade controller on.  If you happen to have one lying around, you can look here to see how you can add it to your existing controller.

How it works

Basically, in each "lane" or "gate" of the shifter, there is a microswitch that is closed when the shifter is in that lane.  (This isn't strictly true, but it'll do for now).  When the shifter is used alongside the Act Labs RS Wheel, these 8 switches are wired so that they function identically to 8 buttons on the wheel.  When the button is depressed, then games that support it natively select the appropriate gear.

What Games support it?

Currently, there are around 20 that support the RS shifter natively.  These can be found on Act Labs website.  Other games can be supported by using using Tom Grandgent's Shift It! utility.  This allows many games to be supported by mapping the gear buttons on the controller to the up/down gear keys on the keyboard.  When the gear changes from one gear to another, the program simply simulates a key press the required no. of times.  eg. When changing from 5th to 2nd, Shift It! will simulate 3 presses of the down gear key, effectively shifting very quickly through the gears.  Shift It! can now also patch games on the fly to natively use the RS Shifter, thus many popular racing games are now supported.

It quickly becomes clear that the standard 4 buttons available on the PC gameport aren't going to be enough, so we have to use compound buttons in order to get the 8 buttons needed.  These buttons must also match the buttons on the Act Labs RS Shifter, so we need to know how these are mapped.  The table on the left shows how the RS Shifter is configured.  As can be seen, we are going to require a configuration with at least 7 buttons, and one POV hat.  Seeing as the button must be down all the time the shifter is in that particular gear, we find that wiring the shifter to the standard gameport means that no extra buttons can be used for other functions such as a handbrake or lights, as pressing this button at the same time as being in gear will either force the controller out of gear, or (Potentially worse) force the controller into another gear.  In order to get extra buttons for a handbrake or other controls, see the Keyboard Modification page.

Wiring Diagram

Ok, so we've pretty much sorted out how it is to be done, now all we require is to wire up the controller for the gears.  The following diagram shows how this is done.

If you are adding this H-Shifter to your current controller, you will need to disable the other switches on the controller.  This can be done by disconnecting the ground wire (Pin 4 and possibly Pin 5 too).  If you wish to be able to switch off the H-Shifter and revert back to having all the buttons functioning on your controller, you can simply place a switch on the ground wire (Pin 4) to switch between the H-Shifter and the rest of the controller.  The following diagram shows how this is done.

Drivers

Seeing as we're using the compound button technique, we're going to need to use special drivers so that Windows recognises our H-Shifter.  Click here to obtain them.