Proto0 User Guide

This guide introduces you to the RGB Sunglasses Proto0 hardware.

Please read this entire page before working with Proto0! Proto0 is early prototype hardware — it is hand-assembled, not mass-produced, and cannot be easily replaced. This guide will help you work with the hardware safely.

What's in a Proto0 kit

A Proto0 kit contains:

1. Glasses — the wearable frame with the RGB LED panel and head strap.
2. Compute Pack — the nRF5340-based controller, installed in a case, with the buttons, status LEDs, and USB-C port.
3. Small battery pack — 2× 900 mAh lithium-polymer cells. See Batteries and charging.
4. Big battery pack — 2× 2000 mAh lithium-polymer cells. See Batteries and charging.
5. Battery extension cables — for routing a battery pack away from the Compute Pack. See Battery extension cables.
6. Battery extension cable with an inline switch — cut battery power without unplugging.
7. Glasses LED Panel cables — three lengths (short, medium, long). All work; see Cable lengths for which to use.

You will also need a USB-C cable to power and charge the Compute Pack.

Hardware Overview

1. (Red) — Glasses LED Panel Connector: a Molex 2.54 mm SL 5-pin connector to attach to the glasses LED panel.
2. (Purple) — Battery Connectors (2×): JST PH connectors for the 2× lithium-polymer cells in the battery pack.
3. (Blue) — Battery Charger Status LED: a simple LED driven directly by the BQ25792 battery charger, separate from the firmware-driven System Status LEDs below. Solid = charging; flashing = charge error; off = not charging.
4. (Teal) — System Status LEDs: two independently controlled, firmware-driven status LEDs — a top LED for charge status and a bottom LED for Bluetooth status. See Status LEDs.
5. (Green) — D-Pad Buttons: Up, Down, Left and Right. Intended to control animations. Currently, only the GLIM player uses the buttons. The "Left" button can be used to enter DFU mode (see Firmware Recovery). Holding Up + Down while booting triggers a factory reset — see Factory Reset.
6. (Yellow) — Recessed Reset Button: press this button to reset the MCU if it's stuck.

There is a USB-C port on the side of the case, near the System Status LEDs, accessible via a cutout.

Status LEDs

The Compute Pack has two firmware-driven RGB status LEDs next to the STATUS label. The top LED (1 below) shows charge / power status and the bottom LED (2) shows boot and Bluetooth status. Each LED can be off, solid, blinking (1 Hz), or "breathing" (a smooth fade — slow or fast). A third, separate LED (3) is driven directly by the battery charger — see the Battery Charger Status LED in the Hardware Overview.

Top LED — Charge / power status

While charging, the color indicates the battery's approximate state of charge (red → orange → yellow → green as it fills); while running on battery, the color indicates the remaining charge (green → orange → red as it drains).

Bottom LED — Boot & Bluetooth status

Important Proto0 Hardware Notes

• There is a third white connector accessible on the Proto0 hardware. It is the same connector type as the battery connectors. Do not attach a battery to this connector. You will damage the battery charger. This connector will be plugged on all shipped units to prevent accidental battery connection. Do not remove the plug.
• If you disassemble the case, the buttons will fall out. When re-assembling the case, please note that the reset button pin is shorter than all other button pins to recess it below the case lid.
• The jumper configuration is now standard across all Proto0 units. Do not remove any jumpers installed on the Proto0 — they are critical for operation of the hardware (for example, the charger-programming jumper configures the charger for 2S LiPo charging at power-up). Removing a jumper may result in hardware damage. If you need guidance on re-configuring the hardware, consult @skalldri.

Battery safety

Assembling your glasses

The Compute Pack and a battery pack clip together on the glasses' head strap — the battery case slides onto rails on the back of the Compute Pack, sandwiching the strap between them. For the full step-by-step with photos, see the Proto0 Assembly Guide.

Unboxing and Setup

When you receive your Proto0 kit, unpack it and identify the parts listed in What's in a Proto0 kit.

Connect a Glasses LED cable between the Proto0 Compute Pack's LED Panel connector and the matching connector on the Glasses LED panel. Pick the length that suits how you're using the glasses (see Cable lengths).

Connect a USB-C cable between your PC (or a USB power source) and the Proto0 Compute Pack. The glasses will power on within 10 s. The bottom status LED will breathe blue to indicate the glasses are waiting for a Bluetooth connection (see Status LEDs).

Powering the glasses — three options: the Compute Pack can run standalone on USB power (no battery required), standalone on battery power (no USB cable), or on USB power while charging the batteries at the same time. See Batteries and charging.

Bluetooth Pairing (first time)

A companion app is available for both Android and iOS. Install the latest release from the Releases page.

Open the app and accept the required permissions to begin Bluetooth scanning. The Proto0 board should be detected in the companion app. Tap Connect to begin the connection process.

Pin-code pairing is required with the Proto0 board. Your phone will prompt you to pair with the new device.

• On Android, this prompt can appear and disappear quickly. Check the swipe-down system notification tray if you don't see it. You should receive a single pairing prompt asking for a PIN code.
• On iOS, the pairing dialog appears as a system alert.

When a PIN code is required, the Glasses LED panel will begin scrolling a 6-digit PIN code. Enter this code into the dialog and accept to complete pairing.

After this initial pairing with your phone, you will no longer need to enter a PIN code to connect to the Proto0 in future.

Once pairing is complete, the device state will be synced with the companion app. You will be able to start interacting with the app to select animations to play.

Batteries and charging

Proto0 supports on-board battery charging. Connect a USB-C cable to charge the attached battery pack; the top status LED shows charge progress (see Status LEDs).

Power sources and charging speed

The Compute Pack charges over its USB-C port and accepts:

• Standard USB — 5 V @ 500 mA (2.5 W).
• USB Power Delivery (USB-PD) — 5 V @ 3 A (15 W) or 9 V @ 3 A (27 W).

Whenever the Glasses LED panel is connected it draws about 1.2 W continuously, even when the display is dark. On a 2.5 W standard USB port, most of that budget goes to just running the glasses — so the batteries charge very slowly on a standard port.

For the fastest, most efficient charging, use a 9 V USB Power Delivery charger.

Battery packs

Two battery packs are available. Each pack is a 2S (two-cell series) pack — its two lithium-polymer cells connect to the two JST-PH battery connectors on the Compute Pack.

The higher rate charges faster; the recommended (lower) rate is gentler on the cells and runs cooler.

Setting the charge current

The firmware ships with a default charge current of 900 mA and does not auto-detect which pack is installed, so set the charge current to match your pack before charging:

• With the Small pack, do not exceed 900 mA (450 mA recommended).
• With the Big pack, you can use up to 2000 mA (1000 mA recommended).

You can set the charge current two ways:

• In the companion app — open the Battery page and set Charge Current (mA) under Charging:

• Over the serial shell — power bq ichg <mA> (see USB Interface). Related read-only commands: power bq status, power bq limits, and power policy.

Charging is enabled by default, but the charger will only actually charge when a battery pack is present (charging with no pack attached can brown out the board).

USB Interface

You can connect the Proto0 hardware to your PC via the USB-C cable. The Proto0 hardware is a composite USB device that exposes several USB endpoints to your PC.

The Proto0 hardware uses Zephyr's default VID:PID 2fe3:0001.

Virtual Serial Ports

Proto0 exposes two serial ports to your PC. The exact naming of these serial ports depends on how your PC enumerates the device. Typically, on Unix-based systems, they are exposed as /dev/ttyACM0 and /dev/ttyACM1.

• Shell port (lower-numbered): Zephyr console. Exposes a shell for development / debugging, as well as application logs.
• MCUmgr port (higher-numbered): a non-human-readable binary protocol that speaks MCUmgr. Used for firmware updates.

Both ports are configured for 115200 baud, but given they are virtual ports this has no effect.

USB Mass Storage

The Proto0 hardware exposes a small ~6.9 MiB USB mass-storage device. It is pre-formatted as a FAT filesystem. Do not attempt to reformat this disk.

The filesystem contains a few folders:

• ext/ — loadable animation extensions (.llext files) that the firmware runs.
• glim/ — GLIM animation files, read dynamically by the GLIM player. You can drop your own .glim files here; on the next reboot the GLIM player re-scans the folder and exposes any new animations to the companion app.
• coredump/ — firmware crash dumps. Empty unless a crash has produced a dump.

Factory Reset

Hold the Up + Down D-Pad buttons together while the glasses boot (press the recessed reset button, or plug in power, with the chord already held). The reset is two-step, with the System Status LEDs showing which step you're in:

1. Settings reset (white flashing, 10 s). Both status LEDs flash white while you hold the chord. Releasing while the white is still flashing cancels: nothing is erased and the glasses boot normally. Once the 10 s are up, the LEDs turn solid white for about a second — at that moment the settings erase has happened and can no longer be canceled: all configuration returns to defaults and Bluetooth pairings are forgotten (you'll need to re-pair your phone), but your GLIM animations and extensions are kept.
2. Full reset (amber flashing, 10 s more). The LEDs then switch to flashing amber. Release anytime from the solid white onward to stop at the settings-only reset — the glasses reboot right away. Keep holding through the entire amber phase and the LEDs turn solid amber while the rest of the full factory reset runs: stored crash dumps and the whole USB filesystem — all GLIM animations and extensions are erased (see USB Interface for restoring files).

Each solid-color step is the confirmation that its erase ran — white flash (still cancelable) → solid white (settings erased) → amber flash → solid amber (files erased) — and the glasses reboot when the sequence ends.

Changed from earlier firmware: the factory reset used to be a single step — holding Up + Down for 10 s erased everything, files included. If you're following an older procedure to recover from a corrupted filesystem or bad files, you now need to keep holding through the amber phase too (about 20 s total); releasing after only 10 s performs the settings-only reset and leaves the filesystem untouched.

Firmware Update

The glasses' firmware can be updated a few ways:

• Over Bluetooth (OTA) — the easiest for end users; done from the companion app. See Updating over Bluetooth (OTA) below.
• Over USB (MCUmgr) — the fast path for developers. See Developer Setup → Flash the firmware.
• Bricked / won't boot? Recover it over USB with MCUboot's DFU mode — see Firmware Recovery.

Updating over Bluetooth (OTA)

The companion app can install firmware straight from GitHub Releases over Bluetooth — no cables required. (BLE OTA is slow — expect several minutes; see Issue 59.)

1. Open the Firmware Update page. Connect to your glasses in the app, open the Controls tab, and tap Firmware Update. The app checks GitHub for the latest release and compares it to what's on the device. If a newer version is available, an Update Available card appears.

2. Download the update. Tap Download Update (or Select Firmware Package to load a .zip you already have). The app shows the package contents — the app-core and network-core images it's about to install.

3. Start the update. Tap Start Update. The app uploads each image over Bluetooth, showing a progress bar. Keep the app open and the phone near the glasses until it finishes.

4. Reset to finish. When the upload finishes, tap Reset Device to boot into the new firmware, then reconnect.