Using A TeensyLC To Emulate The XBOX 360 Controller

After the release of Mortal Kombat X, [Zachery’s] gaming group wanted to branch out into the fighter genre. They quickly learned that in order to maximize their experience, they would need a better controller than a standard gamepad. A keyboard wasn’t going to cut it either. They wanted a fight stick. These are large controllers that look very much like arcade fighting controls and include a joystick and large buttons. [Zachery’s] group decided to build their own fight stick for use with a PC.

[Zachery] based his build around the TeensyLC, which is a 32 bit development board with an ARM processor. It’s also compatible with Arduino. The original version of his project setup the controller as a HID, essentially emulating a keyboard. This worked for a while until they ran into compatibility issues with some games. [Zachery] learned that his controller was compatible with DirectInput, which has been deprecated. The new thing is Xinput, and it was going to require more work.

Using Xinput meant that [Zachery] could no longer use the generic Microsoft HID driver. Rather than write his own drivers, he decided to emulate the XBOX 360 controller. When the fight stick is plugged into the computer, it shows up as an XBOX 360 controller and Windows easily installs the pre-built driver. To perform the emulation, [Zachery] first had to set the VID and PID of the device to be identical to the XBOX controller. This is what allows the Microsoft driver to recognize the device.

Next, the device descriptor and configuration descriptor had to be added to the Teensy’s firmware. The device descriptor includes information such as USB version, device class, protocol, etc. The configuration descriptor includes additional information about the device configuration. [Zachery] used Microsoft Message Analyzer to pull the configuration descriptor from a real XBOX 360 controller, then used the same data in his own custom controller.

[Zachery] programmed the TeensyLC using the Arduino IDE. He ran into some trouble here because the IDE did not include the correct device type for an Xinput device. [Zachery] had to edit the boards.txt file and add three lines of code in order to add a new hardware device to the IDE’s menu. Several other files also had to be modified to make sure the compiler knew what an Xinput device type was.  With all of that out of the way, [Zachery] was finally able to write the code for his controller.

The coming age of ARM chips for the hobbyist

The days of the 8 bit Arduino may be quickly coming to a close. Sure, there will always be a place for AVRs in blinking LEDs and turning on relays, but for doing anything cool – playing MP3s, driving LCD displays, or running a CNC machine – you need the power of a 32 bit chip. [Brian Carrigan] put up a great tutorial on getting started with these bigger, more powerful micros and moving beyond what is possible with an 8 bit PIC or AVR.

These new 32 bit chips are much more powerful, but aren’t exactly hobbyist friendly. Most of the ARM chips we’ve found are stuffed into very fine pitch QFN or QFP packages that require a reflow oven to solder to a board. In fact, we can only find one through-hole Cortex M0 chip that is suited for breadboard development. This doesn’t make it easy to whip up a circuit in a few hours, so builders needing a very powerful microcontroller will be more dependent on dev boards.

Already there are a good number of ARM-based 32 bit dev boards available including the offerings from Leaf Labs, the extremely inexpensive STM Discovery boardKinetis KL25Z Freedom Board, the outrageously powerful BeagleBone, and the perpetually delayed Arduino (over) Due.

None of these boards are particularly new developments; they’ve all been around the block once or twice. However, there are many more options for 32 bit development than the current 8 bit PIC and AVR holy war. We’re going to turn the comments over to Hackaday readers with the following questions: what supersized dev board are you rolling with? What’s good for a beginner, and what should they watch out for?

chipKIT Uno32: first impressions and benchmarks

Following Maker Faire, we’ve had a few days to poke around with Digilent’s 32-bit Arduino-compatible chipKIT boards and compiler. We have some initial performance figures to report, along with impressions of the hardware and software.

Continue reading “chipKIT Uno32: first impressions and benchmarks”