Turn your Meta Quest into a wired "antenna" for DIY face and eye tracking cameras. The ESP32-S3 cameras plug into the headset over USB, and Tracker Bridge forwards their video over WiFi to your PC for EyeTrackVR (ETVR) and Project Babble, without using the cameras' 2.4 GHz WiFi.
Cameras (USB) → USB hub → Meta Quest (Tracker Bridge) → WiFi → PC (ETVR / Project Babble)
- Reads OpenIris cameras in wired (UVC) mode directly through Android's USB host API.
- Serves each camera as an MJPEG HTTP stream in the same format OpenIris uses over WiFi, so ETVR and Babble need no changes: you just paste a URL.
- Keeps running in the background while you play (tested with Steam Link).
- Silent reconnect: if a camera resets or you replug the hub, it comes back without popping up a window. It also starts by itself when you plug the hub in after a reboot.
- Lightweight: no video preview on the headset. With three cameras on a Quest 3S it uses about 6.5% of one CPU core and ~33 MB of RAM.
| Part | Details |
|---|---|
| Headset | Meta Quest 3S (Horizon OS, Android 14) |
| Eye cameras | 2× Seeed XIAO ESP32-S3 Sense, flashed in wired mode with the EyeTrackVR Firmware Flashing Tool v2.0.0 → 60 fps |
| Mouth camera | Official Project Babble tracker, firmware 1.3, wired mode → ~30 fps (that firmware's USB limit) |
| Hub | Generic 4-port USB-C OTG hub |
| PC software | EyeTrackApp 0.3.0 BETA 9, Project Babble v1.1.0, Steam Link for PCVR |
Other OpenIris-based UVC cameras should work, but they haven't been tested.
- A Meta Quest with developer mode enabled, to sideload the APK.
- Cameras running OpenIris firmware in wired / USB (UVC) mode.
- A USB-C OTG hub if you use more than one camera.
- The Quest and the PC on the same network (5 GHz or 6 GHz WiFi recommended).
There's a separate APK for Pico headsets, TrackerBridge-Pico-x.y.z.apk, on the Releases page. It
hasn't been tested on a real Pico yet, so reports are very welcome: please open an issue with your
headset model and what happened.
Differences from the Quest version:
- It asks for Android's regular camera permission instead of Horizon OS's USB cameras permission. Android requires it before any app can read a USB camera; the app never uses the headset's own cameras.
- It installs as a separate app (
dev.rabbit.trackerbridge.pico), so it never conflicts with the Quest version. - The Language button needs Android 13 or newer. On older systems, the app follows the headset's language.
Download the APK from the Releases page and install it with SideQuest, or with adb while the Quest is connected to the PC by cable:
adb install -r TrackerBridge-0.7.0.apk
Optional: precompile the app so it uses less CPU:
adb shell cmd package compile -m speed -f dev.rabbit.trackerbridge
The app is available in English and Spanish. It follows the Quest's language, and you can switch it with the Language button.
- On the Quest, open Library → Unknown Sources → Tracker Bridge.
- Allow the USB cameras permission. Horizon OS requires it before any app can read a USB camera.
- Plug in the hub with your cameras and accept the USB prompt for each one. Tick "use by default" if it's offered, so reconnects are automatic.
- The app lists every camera with its name, its status and its URL.
| Camera | URL | Where to put it |
|---|---|---|
| Left eye | http://QUEST-IP:8081/ |
ETVR → Left |
| Right eye | http://QUEST-IP:8082/ |
ETVR → Right |
| Mouth / face | http://QUEST-IP:8083/ |
Project Babble → Face Camera Address (IpCameraCapture backend) |
- The app shows the Quest's IP. Reserve that IP in your router (DHCP reservation) so the URLs don't change.
- Ports are remembered per camera, by USB serial number. Cameras with "Left" or "Right" in their name get 8081 and 8082; any other camera gets 8083 and up.
- Quick check: open the URL in a browser on your PC and you should see the video.
Plug the hub into the Quest. That's it: Tracker Bridge starts in the background, even after a reboot, and you don't need to open it.
| Problem | What to do |
|---|---|
| A camera doesn't show up | Open Tracker Bridge and tap Scan for cameras. Check the cable and the hub. |
| The app says the Quest rejected the USB permission without a prompt | The USB cameras permission is missing. Grant it in the app's permissions, or reinstall the app and allow it. |
| No image in ETVR or Babble | Check the Quest's IP (shown in the app) and that both devices are on the same network. Try the URL in a browser. |
| The mouth camera runs at ~30 fps | Expected with Babble firmware 1.3 over USB. It still looks smooth in Babble. |
| High "ms lat" in ETVR | ETVR measures that number on the PC, after the frame arrives, so the Quest doesn't affect it. Try GUI OFF or lighter algorithm settings. |
With the cable connected, switch adb to WiFi:
adb tcpip 5555
Connect to the Quest over the network:
adb connect QUEST-IP:5555
Then unplug the cable and plug in the hub. Wireless adb turns off when the Quest reboots. To see the app's logs:
adb logcat -s BridgeService UvcCamera
Requirements: JDK 17 or newer and the Android SDK (platform 35, build-tools 35.0.0). Point Gradle to
your SDK with ANDROID_HOME or a local.properties file containing sdk.dir=/path/to/Android/Sdk.
./gradlew testQuestDebugUnitTest assembleRelease
On Windows, use gradlew.bat. This builds both APKs:
app/build/outputs/apk/quest/release/app-quest-release.apk and
app/build/outputs/apk/pico/release/app-pico-release.apk. They're signed with the debug key, which is
fine for sideloading. The code is shared; each headset's permission and manifest live in
app/src/quest/ and app/src/pico/.
- USB: reads UVC cameras (MJPEG over a bulk endpoint) with
UsbDeviceConnection, bypassing Android's camera stack so it keeps working in the background. The payload parser handles OpenIris' 64-byte payloads and reads that merge several payloads. - Permission: on Horizon OS, USB access to video-class devices requires the runtime permission
horizonos.permission.USB_CAMERA, notandroid.permission.CAMERA. - Network: each camera is an HTTP MJPEG stream (
multipart/x-mixed-replace) that matches OpenIris' WiFi stream. Only the newest frame is sent, so a slow client skips frames instead of adding lag. Packets are tagged with voice priority (WMM). - Background: a
connectedDeviceforeground service. The wake lock and the low-latency WiFi lock are held only while a camera is connected. - Reconnect:
UsbAttachActivityhas no UI. It receives the USB attach event and wakes the service.
MIT: you can use, modify and share this project, as long as you keep the copyright notice.
Created by LoadingRabbit (@celesrabbit-lab) with the help of Claude (Anthropic's AI assistant), who wrote the code and helped debug it on real hardware.
Thanks to the EyeTrackVR and Project Babble communities for OpenIris, ETVR and Babble.
This project is not affiliated with EyeTrackVR, Project Babble or Meta.