THC Project

Off we go!

This Blog/site will follow my THC project.

THC at work during STS-57
THC at work during STS-57

The project was born from the desire to have as much fun as possiable out of Space Shuttle Mission 2007. But hopefully it will also usful for every space sim around.

First some background.

The basic concept is simple and striaght forward. to make a functional and affordable Transitional Hand Controller.

A few important requirements that must be met were made – and they Guide the design.

  1. Due to current application limitations (as of Dec 2008) – the THC must transmit key presses.
  2. The THC must be programmable. For compensation for changing keyboard layout, and to enable support for other games as well.
  3. USB or PS2 interface – with preference to USB for future support (“Built to last”)
  4. Make it as simple as possible – for an electronic noob like me, it’s a must.
  5. 3 axis control at the same time
  6. functionality as close to the Real deal as possible
  7. Ability to Expand, customize and upgrade – simple as possible.

The Design

I’m going for a simple concept, use shelf products (with adaptations) in custom housing. The Design is greatly based on work done by Arcade fans in the MAME project. thanks to them a lot of hardware is available. for example:

For the “Push/pull” axis I will try and mount the stick on four guide rails using the holes for the screws, I will then “lock” it into place with springs to allow about 1.25 Inch (3CM) of

movement. this will cause a microswitch to close triggering the FWD/AFT translation command. but it will probably change a bit when I’ll see the stick.


the I-Pac2 controller I’ve chosen allows 28 buttons (one of them can be a “shift” button). and the THC functions only require 6 of them (four ways+push/pull). that leaves me with 22 unused commands. those would be useful for a keypad.

I will probably add in and external connector to allow easy hooking up of add ons (such as the keypad) – the connector will probably be an LPT port (25 pin serial) or an IDE connector (40 pin interface). the LPT is simpler to obtain while the IDE will allow further upgrade via the I-PAC4 controller, allowing a full shuttle keypad (32 keys + a shift toggle). on IPAC2 the keypad will be more limited and will only have 21 keys (and one shift toggle).

more on that as the project moves ahead.