What sensors are used in this design?

Goodix GT911 Capacitive Touch Controller, Bosch BME280 Environmental Sensor & Accelerometer

What powers this design?

Li-Ion Battery / USB-C 5V Rechargeable

How many components are in the bill of materials?

This design's BOM has 8 components.

A mid-range, rugged, and waterproof e-reader featuring a 7-8 inch sunlight-readable touch display, extensive wireless connectivity, and weeks of battery life.

Morning MallardOct 1, 2026

POWER

MCU

DISPLAY

SENSOR

ACTUATOR

RF

MISC

USB_C → POWERPower
5V charging input to PMIC
POWER → MCUPower
Regulated system power rail
MCU → EPD_DISPLAYSPI
Direct EPD waveform and display control
MCU → TOUCH_PANELI2C
Touch coordinate data and interrupt line
MCU → FRONT_LIGHTPWM
Front-light brightness control
MCU → RF_LTEUART
AT command communication with cellular module
MCU → SENSORSI2C
Environmental and motion sensor telemetry

Part number	Type	Component	Manufacturer	Package	Qty	Datasheet	Match
BQ24074RGTT/BQ24074RGTR	POWER	Texas Instruments BQ24074 & TPS62840 Manages USB-C 5V charging, battery path switching, and provides ultra-low quiescent current 3.3V regulation.	Texas Instruments	—	1	PDF	Matched
4 alternatives consideredAI verified Log in to view alternatives
ESP32-S3	MCU	Espressif ESP32-S3 Dual-core Xtensa processor handling system RTOS, local EPUB parsing, Wi-Fi, and BLE connectivity.	Espressif Systems	56-VFQFN Exposed Pad	1	PDF	Matched
2 alternatives consideredAI verified Log in to view alternatives
GDEW060T3	DISPLAY	Good Display GDEW060T3 E-Paper Panel Sunlight-readable electrophoretic display panel for zero-power static page holding.	Various	—	1	PDF	Pending
2 alternatives consideredAI verified Log in to view alternatives
GT911	SENSOR	Goodix GT911 Capacitive Touch Controller Processes multi-touch gestures and touch interrupts for page navigation.	Hirose Electric	—	1	PDF	Matched
TPS61165	ACTUATOR	Texas Instruments TPS61165 LED Driver Drives white LEDs embedded in the light-guide film for front illumination.	Texas Instruments	—	1	PDF	Matched
1 alternatives consideredAI verified Log in to view alternatives
Cat-M1/NB-IoT	RF	Quectel BG95-M3 Cat-M1/NB-IoT Module Provides low-power cellular connectivity for outdoor syncing, weather updates, and content downloads.	Various	—	1	PDF	Pending
3 alternatives consideredAI verified Log in to view alternatives
USB4105-GF-A	MISC	Standard USB-C Port with ESD Protection Handles 5V power input for battery recharging and wired diagnostic debugging.	GCT	Tape & Reel (TR); Cut Tape (CT); Digi-Reel®	1	PDF	Matched
BME280	SENSOR	Bosch BME280 Environmental Sensor & Accelerometer Detects device orientation for auto-rotation and monitors ambient environment conditions.	Bosch Sensortec	8-VFLGA	1	PDF	Matched

12-16 hoursAdvanced

1

Procurement & Preparation

Procure all raw electronic components including the ESP32-S3 microcontroller, BQ24074RGTT/BQ24074RGTR and TPS62840 power management ICs, GDEW060T3 e-paper panel, GT911 touch controller, TPS61165 LED driver, Quectel BG95-M3 cellular module, USB4105-GF-A USB-C connector, and BME280 sensor.
Inspect the custom 4-layer FR4 printed circuit board (PCB) and verify silkscreen markings for power rails, SPI, I2C, UART, and PWM trace routes.
Prepare SMT stencil, lead-free SAC305 solder paste, and setup the pick-and-place machine coordinates for top and bottom side placement.

2

Hardware Assembly & Wiring

Apply SAC305 solder paste to the PCB pads using the SMT stencil and mount all surface-mount components, focusing on the ESP32-S3, BQ24074 power management chip, TPS62840 regulator, TPS61165 LED driver, GT911 touch controller, BME280 sensor, and USB4105-GF-A USB-C port.
Run the populated PCB assembly through a reflow oven using a standard lead-free thermal profile (peak temperature 245 degrees Celsius).
Manually place and solder the Quectel BG95-M3 Cat-M1/NB-IoT module onto its designated LGA landing pads, and attach the cellular and Wi-Fi/BLE antennas.
Connect the GDEW060T3 E-Paper Panel via its FPC connector to the SPI bus (MOSI, MISO, SCLK, CS, BUSY, DC, RST) driven by the MCU.
Integrate the Goodix GT911 capacitive touch panel via the I2C interface (SDA, SCL, INT, RST) and connect the front-light LED guide film to the TPS61165 driver output through the PWM control line.

3

Firmware Setup

Connect the assembled e-reader hardware via USB-C to the host development workstation and flash the ESP32-S3 bootloader and FreeRTOS-based base firmware image.
Compile and flash the EPUB parsing engine, e-paper waveform display driver routines, and power management sleep state handlers onto the ESP32-S3.
Configure the Quectel BG95-M3 AT command interface over UART (TX, RX, RTS, CTS) for network registration, cellular data syncing, and OTA updates.
Initialize and calibrate the Bosch BME280 environmental sensor and accelerometer via I2C for accurate ambient temperature, humidity, and device orientation tracking.

4

Testing & Calibration

Perform automated boundary-scan and electrical continuity testing on the assembled PCB to verify 3.3V regulation from the TPS62840 and correct BQ24074 battery charging path switching.
Test the GDEW060T3 E-Paper panel refresh cycles, grayscale rendering, and zero-power static image retention across varying ambient temperatures.
Calibrate the GT911 capacitive touch controller multi-touch coordinates and test gesture responsiveness across the 7-8 inch ruggedized cover glass.
Perform final waterproof gasket sealing, drop-resistance validation, and conduct a 48-hour continuous battery life endurance test simulating active reading and standby states.

Rugged Outdoor E-Reader

A mid-range, rugged, and waterproof e-reader featuring a 7-8 inch sunlight-readable touch display, extensive wireless connectivity, and weeks of battery life.

Design Overview

Item	Details
Product Type	Rugged E-Reader
Key Functions	Outdoor and rugged reading (waterproof and sunlight readable), Front-lit display with touch capability, Wi-Fi, Bluetooth, and Cellular (LTE) connectivity, Weeks of battery life via standard USB-C rechargeable power source
Power Source	Li-Ion Battery / USB-C 5V Rechargeable
Connectivity	Wi-Fi, Bluetooth, Cellular (LTE)
Size	Standard 7-8 inch form factor
Environment	outdoor
Difficulty	Advanced
Est. Time	12-16 hours

System Architecture

Power Topology: USB-C 5V feeds BQ24074 charger circuit for single-cell Li-Ion battery; TPS62840 buck regulator steps down battery voltage to an ultra-low quiescent current 3.3V rail powering MCU, sensors, and peripherals.

Module List

Module ID	Type	Name	Function	Voltage
POWER	POWER	Texas Instruments BQ24074 & TPS62840	Manages USB-C 5V charging, battery path switching, and provides ultra-low quiescent current 3.3V regulation.	3.3V / 5V
MCU	MCU	Espressif ESP32-S3	Dual-core Xtensa processor handling system RTOS, local EPUB parsing, Wi-Fi, and BLE connectivity.	3.3V
EPD_DISPLAY	DISPLAY	Good Display GDEW060T3 E-Paper Panel	Sunlight-readable electrophoretic display panel for zero-power static page holding.	3.3V
TOUCH_PANEL	SENSOR	Goodix GT911 Capacitive Touch Controller	Processes multi-touch gestures and touch interrupts for page navigation.	3.3V
FRONT_LIGHT	ACTUATOR	Texas Instruments TPS61165 LED Driver	Drives white LEDs embedded in the light-guide film for front illumination.	3.3V
RF_LTE	RF	Quectel BG95-M3 Cat-M1/NB-IoT Module	Provides low-power cellular connectivity for outdoor syncing, weather updates, and content downloads.	3.8V
USB_C	MISC	Standard USB-C Port with ESD Protection	Handles 5V power input for battery recharging and wired diagnostic debugging.	5V
SENSORS	SENSOR	Bosch BME280 Environmental Sensor & Accelerometer	Detects device orientation for auto-rotation and monitors ambient environment conditions.	3.3V

Design Schemes

Ultra-Low-Power MCU-Centric E-Reader Architecture ★

Centers around a high-efficiency dual-core ESP32-S3 running a lightweight RTOS with direct SPI EPD control and integrated low-power wireless modules to maximize multi-week battery endurance.

Trade-offs: Limited complex browser support compared to full Linux, but achieves exceptional standby battery life and lower BOM cost.

Balanced ARM Linux E-Reader Architecture

Utilizes a power-efficient quad-core ARM Cortex-A53 SoC paired with a dedicated EPD controller, integrated Wi-Fi/BT combo chip, and an external LTE module for robust software support.

Trade-offs: Higher BOM cost and software complexity, but offers superior UI responsiveness and mature Linux ecosystem.

Key IC selection

main MCU

Need: Dual-core processing for RTOS and EPUB parsing, integrated Wi-Fi/BLE, low deep-sleep power consumption for weeks of battery life
Class: Wi-Fi/BLE enabled 32-bit Microcontroller with rich peripheral interfaces
Shortlist: Espressif ESP32-S3 series, Nordic nRF5340 + external Wi-Fi chip
Pick: Select exact ESP32-S3 flash/PSRAM variant based on local EPUB caching requirements and price-availability in current market distribution

Power Path and Step-Down Regulator

Need: Seamless power switching between USB-C input and Li-ion battery, plus ultra-low Iq DC-DC conversion to maximize standby time
Class: Linear/Switching Power Path Manager + Nano-power Step-Down Converter
Shortlist: TI BQ24074 + TPS62840, Analog Devices LTC4040 + MAX17220
Pick: Verify quiescent current specs and thermal dissipation profile during fast charge before locking BOM MPNs

Cellular Connectivity Module

Need: Low-power wide-area cellular connectivity (Cat-M1/NB-IoT) for remote syncing and weather updates with minimal battery drain
Class: Multi-mode LTE IoT wireless module with GNSS option
Shortlist: Quectel BG95-M3, SimCom SIM7080G
Pick: Choose variant matching regional cellular band requirements (North America vs. EMEA/APAC) and carrier certifications

Risk register

ID	Area	Severity	Detail	Mitigation
r1	power	high	EPD panel high-voltage waveform generation and cellular transmission bursts can cause voltage sags on the 3.3V rail, leading to unexpected MCU resets.	Ensure adequate bulk capacitance on the TPS62840 output and isolate analog/RF power planes properly.
r2	firmware	med	Deep sleep current leakage from peripheral ICs (like the touch controller or environmental sensor) can ruin the 'weeks of battery life' requirement.	Implement strict GPIO power-down sequences in firmware and ensure no floating input pins are present during sleep states.
r3	emi	med	Cellular RF bursts from the Quectel BG95 module may couple into the capacitive touch controller (GT911) lines, causing false touch events during data transmission.	Route touch I2C lines away from cellular antenna traces, use ground shielding, and add ferrite beads/filtering if necessary.
r4	mech	high	Rugged waterproof enclosure design restricts thermal dissipation and can trap moisture, affecting the EPD display ribbon cable and USB-C port integrity.	Use waterproof breathable vents, conformal coating on PCBs, and ensure proper gasket sealing around the screen bezel.

Key Components

6/8 modules matched to real parts. See the BOM tab for the full component table.

Texas Instruments BQ24074 & TPS62840 (BQ24074RGTT/BQ24074RGTR)

The candidate BQ24074RGTT/BQ24074RGTR matches the primary MPN with standard reel/cut-tape suffixes, is manufactured by T

Espressif ESP32-S3 (ESP32-S3)

Candidate 1 (ESP32-S3-WROOM-1) is an official Espressif module utilizing the ESP32-S3 SoC, providing the necessary Wi-Fi

Good Display GDEW060T3 E-Paper Panel (GDEW060T3)

Rejected weak/wrong-class catalog hits; using web recommendation: GDEW060T3

Quectel BG95-M3 Cat-M1/NB-IoT Module (Cat-M1/NB-IoT)

Rejected weak/wrong-class catalog hits; using web recommendation: Cat-M1/NB-IoT

Build Summary

Difficulty: Advanced
Estimated time: 12-16 hours
Tools required: Pick-and-Place Machine, Convection Reflow Oven, Hot Air Rework Station, Soldering Iron, Digital Microscope, Multimeter

See the Build tab for the full step-by-step assembly guide.

Generated by YuanQi AI Design System · Query: I would like to build a E reader

Overview

System architecture

Bill of materials

Build guide