HMD Exerciser Kit Hardware

HMD Exerciser

The HMD Exerciser contains all the PC/HMD connectivity and the connector for the HMD Board. It consists of several components as seen below.

HMD Exerciser hardware arrangement
HMD Exerciser hardware arrangement

HMD Exerciser hardware arrangement (actual HW)
HMD Exerciser hardware arrangement (actual HW)

Component boards arranged in order of stacking (actual HW)
Component boards arranged in order of stacking (actual HW)

HMD Exerciser Components

The HMD Exerciser is made up of an Arduino compatible microcontroller and several stacked boards called shields. The individual shields are detailed below in order from bottom to top.

Arduino Mega 2560 R3

The Arduino Mega 2560 R3 is the microcontroller for the HMD Exerciser Main Board and provides an interface for the other boards. Note that any Arduino Mega 2560 R3 compatible board can be used with HMD Exerciser.

If not included with the HMD Exerciser, a compatible power adapter is also required.

Arduino Mega 2560 R3

HMD Shield

The HMD Shield provides connectivity for the HMD Board along with audio input from the HMD and control for up to two servos.

HMD Shield

This board provides the following functionality:

  • Control and power for two servos
  • Audio monitoring
  • Interface connector for the HMD Board

USB Type A SuperSpeed Shield

The USB Type A SuperSpeed shield controls routing of USB from port J1 to any other port. The shield also monitors amperage and voltage drawn from the SUT and displays it on the LCD.

The shield has one USB Type B port (labeled J1) to which the SUT is connected. The shield also has four other USB ports (labeled J2, J3, J4, and J6) to attach devices that act as peripherals to the SUT.

In the HMD Exerciser Kit setup this shield is used primarily for USB 3.0 Multiplexing. If one HMD is attached, this shield connects and disconnects the device over USB. If two HMDs are attached, the shield switches the connection between the two devices, or disconnects both.

USB Type A SuperSpeed Shield

HDMI Shield

The HDMI Shield controls the HDMI connection between the HMD and the SUT.

This shield has three HDMI ports (labeled J1, J2, and J3). J1 should be connected to the SUT while any HMDs are connected to the remaining ports. The connections can be routed so either J2 or J3 connect to J1, or HDMI can be disconnected from the SUT altogether.

HDMI Shield

HMD Tester Board Components

HMD Tester Board

The HMD Tester Board is separate from the HMD Exerciser. It should be secured in the HMD by using a 3D printed mount or another fixture. A custom cable, referred to as the Board-to-Shield cable, connects the HMD Tester Board to the HMD Exerciser.

The HMD Tester Board can

  • Simulate user presence by using IR Sensor and a LED.
  • Detect brightness and color of the HMD displays independently using two TCS34725 color sensors.

When the HMD Tester Board is mounted in the HMD, the IR sensor and the LED should align with the HMD's presence sensor, and the RGB sensors should be in front of the HMD's displays.

HMD Tester Board (display panel side view)
HMD Tester Board (display panel side view)

HMD Tester Board (external side view)
HMD Tester Board (external side view)

HMD Tester Board Mount

The HMD Board attaches to the HMD using a mount specific to that headset. A template 3D print model for the Acer HMD is available. Microsoft does not provide templates for other models.

HMD Board Mount (top view)
HMD Board Mount (top view)

HMD Board Mount (bottom view)
HMD Board Mount (bottom view)]

HMD Tester Board as mounted in the HMD
HMD Tester Board as mounted in the HMD

HMD Exerciser Kit Cables and Accessories

HMD Tester Board-to-Shield Cable

The Board-to-Shield cable connects the HMD Board to the HMD Shield on the HMD Exerciser. It consists of a length of 28 AWG flat ribbon cable (PN AWG28-20/G-1/300-R) and two connectors (PN 0875682093).

HMD board to shield cable and connector

HMD Audio Cable

This cable is a symmetric 3.5mm audio cable that connects from the HMD's audio jack (if available) to the HMD Shield's 3.5mm jack. It can also be connected to the SUT.

HMD audio cable

If the test setup uses two HMDs, it must use a "Y" cable and two HMD audio cables.

Audio "Y" cable

USB 2.0 A-to-B cable

This cable connects the SUT to the HMD Exerciser Main Board for communication and firmware updates.

USB 2.0 A-to-B cable

USB 3.0 A-to-B cable

This cable connects the SUT to the HMD Exerciser's USB Connection Exerciser Shield port J1

USB 3.0 A-to-B cable

HDMI cable

This cable connects the SUT to the HMD Exerciser's HDMI Shield port J1. This cable should meet or exceed HDMI 2.0 spec.

HDMI cable