Espressif ESP32-S3 & Nordic nRF52840 Dual-Chip
Consumer Ar Smart Glass Hardware Design
개요
A lightweight consumer AR smart glass featuring an optical display, local processing, and wireless connectivity for media playback and notifications.
Liu Peter시스템 아키텍처
POWER
MISC
MCU
RF
DISPLAY
SENSOR
AUDIO
- USB_C_INTERFACE → POWER_MANAGEMENTPowerProvides 5V input from USB-C for temple battery charging.
- POWER_MANAGEMENT → CONTROL_PROCESSORPowerRegulated 3.3V power rail to control processor.
- POWER_MANAGEMENT → OPTICAL_DISPLAYPowerRegulated power to Micro-LED display module.
- POWER_MANAGEMENT → SENSOR_SUITEPowerRegulated power to sensor suite.
- CONTROL_PROCESSOR → SENSOR_SUITEI2CI2C communication for IMU and ambient light data reading.
- CONTROL_PROCESSOR → OPTICAL_DISPLAYSPIHigh-speed SPI display pixel data stream.
- CONTROL_PROCESSOR → AUDIO_MODULEGPIODigital audio bus for microphone input and speaker output.
자재 명세서(BOM)
| 부품 번호 | 유형 | 부품 | 제조사 | 패키지 | 수량 | 데이터시트 | 매칭 |
|---|---|---|---|---|---|---|---|
| BQ25155YFPT | POWER | Texas Instruments BQ25155 + TPS63030 Manages Li-Ion temple battery charging over USB-C and supplies stable 3.3V/1.8V rails. | Texas Instruments | 20-XFBGA, DSBGA | 1 | 매칭됨 | |
검토된 대체품 2개 보기projects.detail.aiVerified | |||||||
| FUSB302BMPX | MISC | FUSB302 Type-C Controller Handles USB-C plug orientation detection, power delivery negotiation, and battery charging input. | onsemi | 14-WFQFN Exposed Pad | 1 | 매칭됨 | |
검토된 대체품 2개 보기projects.detail.aiVerified | |||||||
| ESP32-S3 | MCU | Espressif ESP32-S3 & Nordic nRF52840 Dual-Chip Handles local sensor fusion, notification parsing, UI logic, and wireless data streaming. | Espressif Systems | 56-VFQFN Exposed Pad | 1 | 매칭됨 | |
| ESP32-S3 | RF | Integrated Wi-Fi 4 / Bluetooth 5.2 Combo Module (ESP32-S3 Embedded) Provides local connectivity for smartphone media streaming, cloud notifications, and OTA updates. | Espressif Systems | 56-VFQFN Exposed Pad | 1 | 매칭됨 | |
검토된 대체품 2개 보기projects.detail.aiVerified | |||||||
| JBD25FA-W | DISPLAY | JBD Micro-LED Monochromatic Panel with Diffractive Waveguide Projects text notifications and media overlays into the user's field of view with 1500+ nits peak brightness. | JBD | — | 1 | 대기중 | |
| BMI270 | SENSOR | Bosch BMI270 6-Axis IMU + Ambient Light Sensor Tracks head orientation gestures and ambient lighting for auto-brightness adjustment. | Bosch Sensortec GmbH | 14-VFLGA | 1 | 매칭됨 | |
| SPM0687HT5H | AUDIO | Knowles Knowles SPM0687HT5H MEMS Microphone & AAC Miniature Open-Ear Speaker Provides voice command input and discrete audio notification playback. | Knowles | — | 1 | 대기중 | |
검토된 대체품 3개 보기projects.detail.aiVerified | |||||||
조립 가이드
12-16 hoursAdvanced
1
Procurement & Preparation
- Procure all semiconductor components including BQ25155YFPT, FUSB302BMPX, ESP32-S3, Nordic nRF52840, JBD25FA-W Micro-LED, BMI270, SPM0687HT5H, and AAC Miniature Open-Ear Speaker.
- Inspect the flexible printed circuit (FPC) mainboards and temple PCBs for trace integrity, warp, and pad oxidation.
- Prepare stencil alignment fixtures and lead-free Type 4 SAC305 solder paste for SMT assembly of the compact eyewear boards.
2
Hardware Assembly & Wiring
- Apply solder paste to the temple mainboard and place the power management ICs (BQ25155YFPT and TPS63030) along with the FUSB302BMPX Type-C controller.
- Mount the Espressif ESP32-S3 & Nordic nRF52840 Dual-Chip control processors, Bosch BMI270 6-Axis IMU, and Knowles SPM0687HT5H MEMS microphone onto the main processing FPC.
- Integrate and wire the USB-C interface to the power management module linking VBUS, GND, CC1, and CC2 signals for power delivery and charging.
- Connect the Control Processor to the JBD25FA-W Micro-LED Monochromatic Panel via SPI interface (MOSI, SCLK, CS, DC, GND) and establish 3.3V/1.8V power rails.
- Wire the Sensor Suite via I2C (SDA, SCL) and the Audio Module via GPIO/I2S lines (I2S_BCLK, I2S_LRC, I2S_DIN, I2S_DOUT) to complete the internal architecture.
3
Firmware Setup
- Flash the bootloader and primary firmware image onto the Espressif ESP32-S3 via UART/USB programming interface for Wi-Fi/Bluetooth connectivity and UI logic.
- Program the Nordic nRF52840 coprocessor with the BLE stack and sensor fusion firmware for head orientation tracking via the Bosch BMI270 IMU.
- Configure the display driver pipeline to drive the JBD25FA-W Micro-LED panel at 1500+ nits peak brightness with proper gamma correction for the diffractive waveguide.
4
Testing & Calibration
- Perform electrical safety and quiescent current tests on the BQ25155 and TPS63030 power rails to verify stable 3.3V and 1.8V outputs under load.
- Calibrate the Bosch BMI270 6-Axis IMU sensor axes and test ambient light sensor responsiveness for automatic display brightness adaptation.
- Execute optical alignment and projection tests on the JBD Micro-LED panel and diffractive waveguide to ensure crisp text rendering and correct eye-box positioning.
- Test wireless connectivity (Wi-Fi 4 / Bluetooth 5.2), media playback over the open-ear speaker, and voice command capture through the MEMS microphone.
문서
Consumer Ar Smart Glass Hardware Design
A lightweight consumer AR smart glass featuring an optical display, local processing, and wireless connectivity for media playback and notifications.
Executive Summary
This reference design defines the system architecture, critical component candidates, risk register, and validation path for Consumer Ar Smart Glass. It is a system-level design deliverable; verify critical claims with manufacturer evidence and prototype testing before production release.
Design Overview
Requirements Coverage
| Requirement | Architecture coverage | Status |
|---|---|---|
| Optical display module for media and daily notifications | OPTICAL_DISPLAY, CONTROL_PROCESSOR | Covered |
| Control processor for local data processing | CONTROL_PROCESSOR, SENSOR_SUITE | Covered |
| Built-in rechargeable battery with USB-C charging | POWER_MANAGEMENT, USB_C_INTERFACE | Covered |
| Integrated sensor suite | SENSOR_SUITE, CONTROL_PROCESSOR | Covered |
| Standalone Wi-Fi and Bluetooth connectivity | WIRELESS_CONNECTIVITY, CONTROL_PROCESSOR | Covered |
| Item | Details |
|---|---|
| Product Type | Consumer Ar Smart Glass |
| Key Functions | Optical display module for media and daily notifications, Control processor for local data processing, Built-in rechargeable battery with USB-C charging, Integrated sensor suite, Standalone Wi-Fi and Bluetooth connectivity |
| Power Source | Li-Ion Battery |
| Connectivity | WiFi, Bluetooth |
| Size | Standard lightweight eyeglasses frame |
| Environment | wearable |
| Difficulty | Advanced |
| Est. Time | 12-16 hours |
System Architecture
Power Topology: Built-in temple rechargeable Li-Ion cell feeds PMIC (BQ25155), stepping down to a clean 3.3V primary system rail with dedicated low-noise LDOs for the optical display and sensor suite.
Module List
| Module ID | Type | Name | Function | Voltage |
|---|---|---|---|---|
| POWER_MANAGEMENT | POWER | Texas Instruments BQ25155 + TPS63030 | Manages Li-Ion temple battery charging over USB-C and supplies stable 3.3V/1.8V rails. | 3.7V |
| USB_C_INTERFACE | MISC | FUSB302 Type-C Controller | Handles USB-C plug orientation detection, power delivery negotiation, and battery charging input. | 5.0V |
| CONTROL_PROCESSOR | MCU | Espressif ESP32-S3 & Nordic nRF52840 Dual-Chip | Handles local sensor fusion, notification parsing, UI logic, and wireless data streaming. | 3.3V |
| WIRELESS_CONNECTIVITY | RF | Integrated Wi-Fi 4 / Bluetooth 5.2 Combo Module (ESP32-S3 Embedded) | Provides local connectivity for smartphone media streaming, cloud notifications, and OTA updates. | 3.3V |
| OPTICAL_DISPLAY | DISPLAY | JBD Micro-LED Monochromatic Panel with Diffractive Waveguide | Projects text notifications and media overlays into the user's field of view with 1500+ nits peak brightness. | 3.3V |
| SENSOR_SUITE | SENSOR | Bosch BMI270 6-Axis IMU + Ambient Light Sensor | Tracks head orientation gestures and ambient lighting for auto-brightness adjustment. | 3.3V |
| AUDIO_MODULE | AUDIO | Knowles Knowles SPM0687HT5H MEMS Microphone & AAC Miniature Open-Ear Speaker | Provides voice command input and discrete audio notification playback. | 3.3V |
Power Tree and Signal Interfaces
| From | To | Type | Interface / rail | Voltage |
|---|---|---|---|---|
| USB_C_INTERFACE | POWER_MANAGEMENT | power | Power | 5.0V |
| POWER_MANAGEMENT | CONTROL_PROCESSOR | power | Power | 3.3V |
| POWER_MANAGEMENT | OPTICAL_DISPLAY | power | Power | 3.3V |
| POWER_MANAGEMENT | SENSOR_SUITE | power | Power | 3.3V |
| CONTROL_PROCESSOR | SENSOR_SUITE | power | I2C | 3.3V |
| CONTROL_PROCESSOR | OPTICAL_DISPLAY | power | SPI | 3.3V |
| CONTROL_PROCESSOR | AUDIO_MODULE | data | GPIO | 3.3V |
Design Schemes
Heterogeneous Dual-Chip Micro-LED Architecture ★
Utilizes a low-power application processor paired with an ultra-efficient MCU and Micro-LED waveguide optics for high outdoor brightness and strict thermal limits.
Trade-offs: Higher component complexity and FPC routing requirements across the temple hinge, but significantly better outdoor readability and battery longevity compared to Micro-OLED Birdbath setups.
Key IC selection
Main Dual-Core MCU & Wireless Processor
- Need: Execute local UI logic, drive Micro-LED display interfaces, process 6-axis IMU sensor fusion, and manage dual-mode wireless connectivity under tight temple space and power constraints.
- Class: Dual-chip ultra-low-power wireless MCU architecture (Wi-Fi/BLE SoC + dedicated BLE/sensor co-processor)
- Shortlist: Espressif ESP32-S3 (Dual Xtensa LX7 + Wi-Fi/BLE) + Nordic nRF52840 (Cortex-M4 BLE), Qualcomm QCC5100 series + custom low-power companion MCU
- Pick: Select commercial automotive/consumer-grade dual-chip sets balancing package size (WLCSP/QFN), standby current, and rich peripheral support for display and sensors.
Battery Charger & DC-DC Power Path
- Need: Safely charge a miniature temple Li-Ion battery via USB-C with micro-amp termination currents and supply stable 3.3V and 1.8V rails despite battery voltage sagging.
- Class: I2C-controlled linear battery charger with integrated LDO combined with a high-efficiency synchronous buck-boost converter
- Shortlist: TI BQ25155 (Ultra-low quiescent current charger + LDO) + TI TPS63030 (High efficiency buck-boost), Analog Devices LTC4124 + MAX77827
- Pick: Choose ultra-small footprint WLCSP package PMIC components capable of sub-microamp shutdown currents to maximize standby life in smart glasses.
Type-C Controller & Port Protection
- Need: Detect USB-C plug orientation, handle CC pin logic, and negotiate baseline power delivery for charging the device safely.
- Class: Standalone USB Type-C controller IC with I2C host interface
- Shortlist: FInsemi / Onsemi FUSB302, TI TPS65982 / STMicroelectronics STUSB1602
- Pick: Select space-saving WLCSP-9 or tiny QFN Type-C controllers with minimal external passives and low active power consumption.
Risk register
| ID | Area | Severity | Detail | Mitigation |
|---|---|---|---|---|
| r1 | thermal | high | JBD Micro-LED running at 1500+ nits peak brightness combined with the ESP32-S3 Wi-Fi radio active in the confined temple space will cause localized heating against the user's head. | Implement aggressive dynamic thermal throttling in firmware based on IMU/board temperature sensors, and utilize internal copper planes in the temple PCB for heat spreading. |
| r2 | emi | high | High-frequency display interface lines running alongside the Wi-Fi/BT 2.4GHz antenna and sensitive I2C sensor traces inside the narrow temple arm risk severe desense and signal integrity degradation. | Use differential routing or shield flexible printed circuits (FPCs), apply strict ground plane partitioning, and keep high-speed display traces well-isolated from the 2.4GHz antenna clearance zone. |
| r3 | power | med | The small capacity of the temple-mounted Li-Ion battery combined with high peak current spikes from Wi-Fi transmission and Micro-LED bursts can trigger premature battery UVLO trips. | Select a battery chemistry with high pulse-discharge capability, optimize TPS63030 transient response, and implement soft-start load shedding in firmware for high-current peripherals. |
Bring-up and Validation Plan
- Power-off inspection and rail resistance checks
- Current-limited first power-up; verify every rail before enabling loads
- Validate interfaces and timing one subsystem at a time
- Run thermal, fault-injection, EMC pre-scan, and endurance tests for the target environment
Key Components
5/7 modules matched to real parts. See the BOM tab for the full component table.
Texas Instruments BQ25155 + TPS63030 (BQ25155YFPT)
BQ25155YFPR is the active production IC variant in tape and reel packaging matching the primary MPN BQ25155 from Texas I
Espressif ESP32-S3 & Nordic nRF52840 Dual-Chip (ESP32-S3)
The candidate matches the primary MPN (ESP32-S3) and the preferred manufacturer (Espressif Systems).
JBD Micro-LED Monochromatic Panel with Diffractive Waveguide (JBD25FA-W)
Rejected weak/wrong-class catalog hits; using web recommendation: JBD25FA-W
Knowles Knowles SPM0687HT5H MEMS Microphone & AAC Miniature Open-Ear Speaker (SPM0687HT5H)
Rejected weak/wrong-class catalog hits; using web recommendation: SPM0687HT5H
Build Summary
- Difficulty: Advanced
- Estimated time: 12-16 hours
- Tools required: Anti-static inventory bins, ESD microscope, Optical Inspection System, Calipers, Stencil Printer, Squeegee
See the Build tab for the full step-by-step assembly guide.
Evidence and Limitations
- Confirm part parameters, certifications, and compatibility against current manufacturer documents.
- Treat industry compliance without test or certificate evidence as a compliance gap, not an approval.
- See Reference Images for visual artifacts and Build Guide for detailed assembly and bring-up steps.