Description
ESP32-S3 4.2inch RLCD Development Board, 300 × 400 Resolution, Supports Wi-Fi & BLE Dual-mode Communication And AI Voice InteractionESP32-S34.2inch
RLCD development board

E-paper-like Reading Experience, Faster Refresh Response

AI Voice Interaction, Temperature & Humidity Monitoring, DIY Learning & Development

Version options

ESP32-S3-RLCD-4.2
Comes with a 18650 Lithium Batt

ESP32-S3-RLCD-4.2-EN
Without 18650 Lithium Batt

Features

TheESP32-S3-RLCD-4.2is a RLCD AIoT development board based on ESP32-S3, supporting Wi-Fi and BLE dual-mode communication. Onboard 4.2inch RLCD with low power consumption, e-paper-like display experience, and faster refresh response. Integrated with audio codec circuit, dual microphones, speaker, SHTC3 high-precision temperature and humidity sensor, TF card slot, RTC header, and Lithium Batt charging and discharging management circuit, etc. Reserved USB, UART, I2C, and multiple GPIO interfaces for easy expansion. Supports AI Voice Interaction, temperature and humidity monitoring, and IoT control, making it suitable for DIY desktop smart ornaments, electronic calendars, AI smart devices, and other applications. Also ideal for product prototyping.

• Adopts high-performance Xtensa 32-bit LX7 dual-core processor, up to 240MHz main frequency
• Supports 2.4GHz Wi-Fi and Bluetooth 5 (LE), with onboard antenna
• Built-in 512KB Static RAM, 384KB ROM, with integrated 16MB Flash and 8MB PSRAM
• Onboard 4.2inch RLCD, 300 × 400 resolution, features reflective imaging and no backlight required
• Equipped with a dual-microphone array, enabling audio algorithms such as noise reduction and echo cancellation, suitable for accurate voice recognition and near-field / far-field voice wake-up applications
• Onboard PCF85063 RTC chip and SHTC3 temperature & humidity sensor for accurate RTC management and environmental monitoring
• Onboard 18650 Lithium Batt holder and RTC backup Batt header. The RTC backup Batt header supports a rechargeable RTC Batt and dual modes of main Batt power supply and RTC independent power supply
• Onboard TF card slot for external storage of images or files
• Onboard programmable KEY and BOOT side buttons for customized function development
• Reserved 2 × 8PIN 2.54mm pitch female header for convenient external expansion

Specificationsdisplay panelRLCDDisplay size4.2inchresolution300 × 400grey scale2interfaceSPIDisplay ModereflectiveDriver ICST7305display colorblack, white
Onboard audio codec chip

Supports high-quality audio processing, providing clear and high-quality audio input and output

Supports AI Voice Interaction

Allows access to online large model platforms such as DeepSeek, Doubao, etc

Reflective Liquid Crystal Display

TheReflective Liquid Crystal Display (RLCD)is a specialized type of LCD that efficiently utilizes ambient light (such as natural sunlight or indoor illumination) instead of a backlight, achieving both energy efficiency and environmental friendliness. Thanks to its reflective design, RLCDs perform exceptionally well in bright environments, where conventional LCDs may suffer from glare and reduced visibility. By effectively reflecting external light, the RLCD can provide a clear, high-quality visual experience.

Application Scenarios

Ideal for DIY desktop smart ornaments, electronic calendars, AI smart devices,
outdoor displays and more

Supports ESP-IDF, Arduino IDE

Comprehensive SDK, dev resources, and tutorials to help you easily get started

What's On Board

1. ESP32-S3-WROOM-1-N16R8
   The SoC with Wi-Fi and Bluetooth, 240MHz main frequency, integrated with 16MB Flash and 8MB PSRAM
2. ES7210
   ADC chip for echo cancellation circuit
3. ES8311
   low-power audio codec chip
4. BOOT button
   Press it when powering on to enter download mode
5. PWR button
   long press to power off, short press to power on
6. KEY button
   customizable for other functions
7. SHTC3 temperature and humidity sensor
   provides ambient temperature and humidity measurement, enabling environmental monitoring function
8. PCF85063
   RTC chip with timekeeping function

9. MX1.25 2PIN speaker header
   audio output signal, for connecting external speaker
10. RTC independent power supply header
    supports PH1.0 rechargeable RTC Batt only
11. 2 × 8PIN 2.54mm pitch female header
    
12. 18650 Lithium Batt holder
    
13. Dual-microphone array design
    dual-microphone array, paired with ES7210 to achieve echo cancellation
14. CHG charging indicator
    off when fully charged
15. WRN warning indicator
    stays on when Batt is reverse-connected
16. Type-C port
    for program burning and log printing
17. TF card slot
    supports FAT32 TF card for data expansion

Pin DefinitionOutline Dimensions
Resources & ServicesPackage Content

Weight:0.187 kg

* the 18650 Lithium Batt is optional.

1. ESP32-S3-RLCD-4.2 host x1
2. OPTIONAL18650 rechargeable Lithium Batt x1
3. 8Ω 2W MX1.25 2PIN speaker x1
4. Screwdriver x1

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