Components#

IMU Trackers#

Each tracker consists of:

  • BNO085 9-axis IMU sensor

  • ESP32 microcontroller for Wi-Fi streaming

  • 3D-printed enclosure with a rigidly mounted AprilTag

  • LiPo battery (500 mAh, ~4 hours runtime)

You need 9 trackers in total, placed at the following body locations:

Tag ID

Body Location

0

Pelvis

1

Left Shoulder

2

Right Shoulder

3

Left Elbow

4

Right Elbow

5

Left Hip

6

Right Hip

7

Left Knee

8

Right Knee

IMU / AprilTag / Joint Mapping#

IMU ID

Body Part

AprilTag ID

SMPL-X Joint

1

Pelvis

0

0

2

Left Shoulder

1

16

3

Right Shoulder

2

17

4

Left Elbow

3

18

5

Right Elbow

4

19

6

Left Hip

5

1

7

Right Hip

6

2

8

Left Knee

7

4

9

Right Knee

8

5

Project Aria Glasses#

RoSHI uses Project Aria glasses for:

  • 6-DoF head tracking via onboard SLAM

  • Egocentric RGB video capture

  • Machine Perception Services (MPS) for post-processing

Bill of Materials#

Item

Quantity

Approx. Cost

BNO085 IMU breakout

9

$12 each

ESP32 dev board

9

$8 each

LiPo battery (500 mAh)

9

$5 each

AprilTag prints (Tag36h11)

9

~$2 total

3D-printed enclosures

9

~$15 total

Velcro straps

9

~$10 total