XREAL Aura-Inspired Optical See-Through AR Glasses with Head-Tracked HUD and Voice Assistant

Optical see-through AR glasses float digital information in front of one eye without blocking the real world: the wearer reads a clock, a notification or a compass heading while still seeing the room and the people around them. XREAL Aura-Inspired Optical See-Through AR Glasses answers that idea at student scale, with a small OLED above one lens reflecting off a 45-degree beam-splitter film, an ESP32 tracking head orientation with an MPU6050 sensor, and a phone app forwarding notifications and voice replies over Bluetooth Low Energy. The idea made headlines on 28 October 2026, when XREAL launched Aura as the first wired XR glasses powered by Android XR, with Sony Micro-OLED displays and a reported weight under 95 grams. This student build translates that headline honestly to bench scale: one eye instead of two, head orientation instead of positional tracking, a manual tint slider instead of electronic dimming, and voice handling on the phone.

The end-to-end mechanism runs from a turn of the wearer's head to text floating in front of one eye, with the phone doing the work the glasses cannot. The MPU6050 sensor measures acceleration and rotation on three axes each, and the ESP32 converts those readings into head orientation — yaw, pitch and roll. The ESP32 draws the current HUD page on the small OLED display, and the beam-splitter film in front of the lens reflects that display into the eye while transmitting the light of the room, so the wearer sees both at once. Meanwhile the phone companion app watches for notifications and, when the temple button is pressed, transcribes a spoken command and sends a short text reply back over Bluetooth Low Energy for the ESP32 to display. Every page is head-locked, moving with the wearer, which is all a 3-axis orientation sensor can honestly support.

1. The builder prints the glasses frame, fits clear acrylic lenses, and mounts the small OLED display above the right lens angled toward a 45-degree beam-splitter film fixed in front of that lens.
2. The builder wires the MPU6050 sensor, the temple push button and a protected single-cell battery to the ESP32 board housed in the temple arm, keeping the wiring short so the frame stays wearable.
3. The builder pairs the phone companion app over Bluetooth Low Energy and grants it notification access, then checks that a test notification from the phone appears on the HUD.
4. The builder calibrates the headset by holding the head level and pressing the temple button to zero the yaw, and repeats this zeroing whenever the compass heading has drifted.
5. For the head-tracking demonstration, the builder turns slowly left and right while the examiner watches the compass needle and heading in degrees follow the head on the HUD.
6. For the voice demonstration, the builder presses the temple button, speaks a command such as "show time", and the phone's transcription returns a short text reply that appears on the HUD page.
7. The builder slides the tint filter across the lens to show manual dimming, then notes the yaw drift observed after two minutes of wear and the re-zeroing step that corrects it, so the report states the limitation with its own measured observation.

Tech stack:

• ESP32 development board · dual-core controller and BLE link
• MPU6050 motion sensor · 3-axis accelerometer and gyroscope head tracking
• SSD1306 OLED display · 128 by 64 beam-splitter HUD
• Beam-splitter lens · clear lens with 45-degree reflective film
• 3D-printed glasses frame · PLA frame with temple electronics housing
• Phone companion app · notification forwarding and voice commands
• Bluetooth Low Energy · glasses to phone link
• HUD pages · clock compass notifications and voice replies

These AR glasses combine four capabilities that make a complete see-through wearable prototype rather than a display strapped to a frame. First, the beam-splitter optics put text in front of one eye while the clear lens keeps the room visible, which is the hardest part to demonstrate convincingly. Second, head tracking turns the HUD from a static screen into something that responds to the wearer: the compass heading follows head yaw, so turning the head visibly turns the needle. Third, the phone companion app gives the glasses something worth showing, forwarding real notifications and short voice replies over Bluetooth Low Energy instead of canned demo text. Fourth, the manual tint slider reproduces Aura's dimming idea in a form a student can build, trading electronic dimming for a filter the wearer slides by hand. Together these capabilities let a student demonstrate optics, motion sensing, wireless links and voice interaction in one wearable viva demonstration.

• [Optical see-through HUD on one eye] A 128 by 64 OLED display mounted above the right lens reflects off a 45-degree beam-splitter film into the eye, so HUD text appears over the wearer's view while the clear lens keeps the room visible — implemented in the base build.
• [Head-tracked compass and clock] The MPU6050 sensor measures head orientation and the ESP32 redraws the compass heading as the wearer turns, with the clock always visible beside it, so the HUD visibly responds to head movement — implemented in the base build.
• [Phone notifications on the lens] The companion app forwards phone notifications over Bluetooth Low Energy and the glasses show the sender and a short message line, so a message arriving on the phone appears in the wearer's view within seconds — implemented in the base build.
• [Voice commands through the phone] Pressing the temple button starts listening on the phone, the phone transcribes the command and sends back a short text reply that appears on the HUD, for commands such as showing the time, the compass or the next page — implemented in the base build.
• [Manual tint slider for dimming] A sliding tint filter clipped over the lens darkens the wearer's view by hand, standing in for the electronic dimming of the commercial glasses with a mechanism a student can build and explain — implemented in the base build.
• [Four HUD pages on a temple button] Short presses of the temple button cycle four pages — clock plus compass, notifications, voice replies and reminder — so a viva demonstration walks through every capability without touching the phone — implemented in the base build.
• [Companion app with live yaw readout] The companion app shows live head yaw in degrees, the connected status and the forwarded notification feed, giving the examiner a second screen that proves the glasses and phone are actually linked — implemented in the base build.
• [World-locked windows and hand tracking] Future scope only, not implemented: windows pinned to fixed points in the room and gesture control, listed as an extension rather than a claimed feature, since the base build tracks head orientation only and shows head-locked pages.

• Complete fabricated AR glasses rig (3D-printed frame, clear lenses, beam-splitter film, OLED display module, MPU6050 sensor board, ESP32 temple board, temple button, sliding tint filter, protected battery pack)
• Glasses firmware and phone companion app (4 HUD pages, head-tracked compass, notification forwarding, voice-command replies over Bluetooth Low Energy, live yaw readout)
• Calibration and measurement guide (yaw zeroing procedure, drift observation sheet, indoor demonstration setup, Bluetooth pairing checklist)
• Project report PDF (see-through optics background, head-tracking method, wireless link design, calibration procedure, results template)
• PPT presentation for final review
• Viva Q&A preparation document (optical see-through concept, beam-splitter optics, MPU6050 orientation sensing, yaw drift, Bluetooth Low Energy limits, trend-glasses differences)