1. Introducció
The EoRa-S3-900TB is a versatile development board designed by EBYTE, integrating the powerful ESP32-S3FH4R2 chip with a LoRa module. This board is engineered for a wide range of applications requiring Wi-Fi, Bluetooth LE, and LoRa wireless communication capabilities. It features a compact design with essential peripherals for rapid prototyping and testing.
The ESP32-S3 is a low-power MCU system-on-chip (SoC) that supports 2.4 GHz Wi-Fi and Bluetooth LE wireless communication. The chip integrates a high-performance 32-bit LX7 dual-core processor, an ultra-low-power co-processor, Wi-Fi baseband, Bluetooth baseband, RF module, and peripherals up to 240 MHz. The ESP32-S3FH4R2 package includes 384 KB of ROM, 512 KB of SRAM, 16 KB of RTC SRAM, 4 MB of FLASH, and 2 MB of PSRAM.

Imatge: Anglesa view of the EoRa-S3-900TB Test Board, showcasing its compact form factor and various components.
2. Característiques clau
- Processador: 32-bit LX7 dual-core processor, up to 240 MHz.
- Memòria: Integrated 4 MB FLASH and 2 MB PSRAM.
- Connectivitat sense fils: Supports 2.4 GHz Wi-Fi (IEEE 802.11b/g/n) and Bluetooth LE (Bluetooth 5, Bluetooth mesh).
- LoRa Module: E22-900MM22S with SX1262 chip, supporting 850 ~ 930 MHz operating frequency and +22 dBm max output power.
- Visualització: Integrated 0.96-inch OLED display.
- Emmagatzematge: SD card slot for expanded storage.
- Gestió d'energia: Li-ion battery charging circuit with a rated charging current of 500mA.
- Interfície: Type-C interface with USB 2.0 protocol for power and data.
- Antena: Common antenna for Wi-Fi and Bluetooth.
3. Especificacions tècniques
| Especificació | Valor |
|---|---|
| Nom del model | EoRa-S3-900TB |
| Marca | EBYTE |
| Velocitat de la CPU | 240 MHz |
| Capacitat d'emmagatzematge de memòria | 6 MB (4MB FLASH + 2MB PSRAM) |
| Tecnologia de connectivitat | Bluetooth, WiFi |
| Protocols Wi-Fi | IEEE 802.11b/g/n (20 MHz and 40 MHz bandwidths) |
| Tarifes de dades Wi-Fi | Up to 150 Mbps (1T1R mode) |
| Bluetooth LE Rates | 125 Kbps, 500 Kbps, 1 Mbps, 2 Mbps |
| Freqüència LoRa | 850 ~ 930 MHz |
| LoRa Max Output Power | +22 dBm |
| OLED Display Size | 0.96 polzades |
| Corrent de càrrega de la bateria | 500mA (rated) |
| Interfície | Type-C (USB 2.0) |
4. Contingut del paquet
The EoRa-S3-900TB package typically includes the following components:
- EoRa-S3-900TB Development Board (with integrated Type-C interface, E22-900MM22S LoRa module, 0.96-inch OLED display, SD card slot, Li-ion battery charging circuit, and power circuit)

Image: The product packaging box, displaying manufacturer details and certifications.
5. Hardware Components and Pinout
The EoRa-S3-900TB board is designed with various accessible components and GPIO pins for development and testing. Below are diagrams illustrating the main components and the pin definitions.

Image: Detailed diagram of the EoRa-S3-900TB board highlighting key components and their functions, including the LoRa module, ESP32-S3 chip, and various interfaces.
5.1. Component Introduction
| NO | Maquinari principal | Introducció de components |
|---|---|---|
| 1 | E22-400MM22S or E22-900MM22S | Ultra-small size independently developed by Chengdu Ebyte Electronics Co., Ltd. Based on the new generation of LoRa RF chip SX1262. E22-400MM22S and E22-900MM22S are produced by American Semtech and are suitable for 433MHz, 470MHz, 868MHz and 915MHz patch-type LoRa wireless modules. |
| 2 | ESP32-S3 chip | ESP32-S3 is a low-power MCU system-on-chip (SoC) that supports 2.4GHz Wi-Fi and Bluetooth LE wireless communication. |
| 3 | 3D omnidirectional antenna (Wi-Fi antenna) | Maximum gain 4.9dBi, 2.4G Wi-Fi omnidirectional antenna |
| 4 | IPEX seat (Wi-Fi antenna) | IPEX first generation socket, 2.4G Wi-Fi antenna |
| 5 | IPEX seat (LoRa antenna) | IPEX first generation seat, LoRa antenna |
| 6 | SMA radio frequency interface (LoRa antenna) | Full length 14.5mm SMA head, LoRa antenna |
| 7 | Tecla de restabliment | Botó de restabliment |
| 8 | interruptor | For completely disconnecting battery power |
| 9 | GPIO external interface | GPIO from ESP32 |
| 10 | GPIO external interface | UART serial port TXD |
| 11 | Interfície de bateria externa | SH 1.25mm, 2pin battery interface |
| 12 | LED d'un sol color | Addressable RGB LED, driven by GPIO8 |
| 13 | LED bicolor | Charging indicator light, red when charging, green when fully charged |
| 14 | Pantalla OLED | Pantalla OLED d'0.96 polzades |
| 15 | Clau d'arrencada | Download button. Press and hold the Boot key and press the Reset key to enter the "firmware download" mode and download the firmware through the serial port. |
| 16 | USB download port | USB interface can be used as the power supply for the development board or the communication interface between PC and ESP32-S3 chip |
| 17 | Ranura per a targeta TF | Short body TF card slot |
| 18 | Pin | All available GPIO pins (except the SPI bus of the flash) have been led to the pin header of the development board. Please see pin headers for more information. |
5.2. Definició del pin

Image: Diagram illustrating the pin layout and dimensions of the EoRa-S3-900TB board, crucial for connecting external components.
| NO | Nom del pin | Tipus de pin | Ús de pins |
|---|---|---|---|
| 1 | VCC | Font d'alimentació | Power pin, can be used as 5V power output after normal power supply |
| 2 | GND | Font d'alimentació | Potència GND |
| 3 | 3.3VA | Font d'alimentació | The power pin can be used as a 3.3V power output after normal power supply. It is not allowed to connect to 3.3V or other external power. |
| 4 | GND | Font d'alimentació | Potència GND |
| 5 | GPIO42 | D'entrada i sortida | - |
| 6 | GPIO46 | D'entrada i sortida | - |
| 7 | GPIO41 | D'entrada i sortida | - |
| 8 | GPIO40 | D'entrada i sortida | - |
| 9 | GPIO39 | D'entrada i sortida | - |
| 10 | U0RXD | Entrada | UART serial port RXD |
| 11 | U0TXD | Sortida | UART serial port TXD |
| 12 | GPIO38 | D'entrada i sortida | - |
| 13 | GPIO16 | D'entrada i sortida | - |
| 14 | GPIO15 | D'entrada i sortida | - |
| 15 | RST | D'entrada i sortida | Connect to ESP32-S3 reset pin |
| 16 | GPIO08 | D'entrada i sortida | Connect to the reset pin of the LoRa module |
| 17 | GPIO12 | D'entrada i sortida | - |
| 18 | GPIO48 | D'entrada i sortida | - |
| 19 | GPIO47 | D'entrada i sortida | - |
| 20 | GPIO35 | D'entrada i sortida | Connect to DIO1 of LoRa module |
| 21 | GPIO34 | D'entrada i sortida | BUSY connected to LoRa module |
| 22 | GPIO33 | D'entrada i sortida | - |
| 23 | GPIO36 | D'entrada i sortida | BOOT button connected to the base panel |
| 24 | GPIO37 | D'entrada i sortida | LED connected to base plate |
| 25 | GPIO38 | D'entrada i sortida | - |
| 26 | GPIO37 | D'entrada i sortida | - |
6. Primers passos
6.1. Donant poder a la junta
The EoRa-S3-900TB can be powered via its Type-C USB port. Connect the board to a computer or a 5V USB power adapter using a standard Type-C cable. The board also supports Li-ion battery power, with an integrated charging circuit. Ensure the battery is connected to the external battery interface (SH 1.25mm, 2pin) if using battery power.
6.2. Descàrrega de firmware
To upload new firmware or programs to the ESP32-S3 chip:
- Connect the board to your computer via the Type-C USB download port.
- Manteniu premut el botó Clau d'arrencada (labeled 15 in the component introduction diagram).
- While holding the Boot key, briefly press the Tecla de restabliment (labeled 7).
- Release the Boot key. The board should now be in firmware download mode, ready to receive firmware via the serial port.

Image: The EoRa-S3-900TB board featuring its integrated 0.96-inch OLED display, which can be used for status indicators or data output.
7. Modes de funcionament
7.1. Wi-Fi Operating Modes
The ESP32-S3 supports various Wi-Fi operating modes:
- Infrastructure BSS Station mode (STA mode): The module acts as a client and connects to an existing Wi-Fi access point or router. In this mode, the module does not provide connections to other devices.
- SoftAP mode (AP mode): The module functions as a wireless access point, allowing other Wi-Fi devices to connect to it. It can establish TCP/IP-based server, client, and UDP connections, supporting up to 6 stations and up to 7 TCP Socket transmissions.
- Station + SoftAP mode: The module operates simultaneously as both a client (STA) and an access point (AP).

Image: Visual representation of the Wi-Fi operating modes (AP and STA) supported by the EoRa-S3-900TB board, illustrating how it can function as an access point or connect to an existing network.
7.2. Bluetooth LE Data Rates
The Bluetooth LE functionality supports multiple data rates, providing flexibility for various applications:
- 125 Kbps
- 500 Kbps
- 1 Mbps
- 2 Mbps

Image: Diagram illustrating the adjustable multi-level data rates for Bluetooth Low Energy (BLE) supported by the board, ranging from 125 Kbps to 2 Mbps.
8. Escenaris d'aplicació
The EoRa-S3-900TB board is suitable for a wide array of applications due to its versatile connectivity and processing capabilities:
- Smart home and industrial automation
- Healthcare devices
- Smart agriculture systems
- Service robotics
- General Purpose Low Power IoT Sensor Hubs
- General Purpose Low Power IoT Data Loggers
- Audio devices and camera video streaming
- USB devices and consumer electronics
- Speech recognition and image recognition systems
- Wi-Fi + Bluetooth network cards
- Touch and proximity sensing applications

Imatge: Examples of diverse application scenarios for the EoRa-S3-900TB, including smart home, medical equipment, audio equipment, smart agriculture, service robots, and electronic products.
9. Solució De Problemes
If you encounter issues with your EoRa-S3-900TB board, consider the following common troubleshooting steps:
- Sense energia: Ensure the Type-C cable is securely connected and the power source (USB port or adapter) is functional. If using a battery, check its charge level and connection.
- Error de càrrega de firmware: Verify that the board is in download mode (Boot key pressed during reset). Check your serial port settings and driver installation on your computer.
- Problemes de connectivitat Wi-Fi/Bluetooth: Ensure antennas are properly connected. Check your code for correct Wi-Fi credentials or Bluetooth pairing procedures. Verify that the module is operating in the correct mode (AP, STA).
- La pantalla OLED no funciona: Check connections to the OLED display. Ensure your code is correctly initializing and sending data to the display.
- Targeta SD no detectada: Ensure the SD card is inserted correctly into the TF card slot. Check your code for proper SD card initialization and file operacions del sistema.
10. Manteniment
To ensure the longevity and optimal performance of your EoRa-S3-900TB board:
- Mantenir net: Regularly clean the board with a soft, dry brush or compressed air to remove dust and debris. Avoid using liquids or harsh chemicals.
- Manejar amb cura: Avoid dropping the board or subjecting it to physical shocks. Handle by the edges to prevent damage to components.
- Emmagatzematge adequat: Store the board in a dry, cool environment, away from direct sunlight and extreme temperatures. Use anti-static bags if storing for extended periods.
- Apagueu quan no estigui en ús: Disconnect power when the board is not in use, especially if using battery power, to prevent unnecessary discharge.
11. Assistència i garantia
For technical support, documentation, or further inquiries regarding the EoRa-S3-900TB test board, please contact the manufacturer:
Fabricant: Chengdu Ebyte Electronic Technology Co., Ltd.
Weblloc: http://www.cdebyte.com/
For EU customers, the authorized representative is:
REP. UE: evalmaster Consulting GmbH
Bethaniestr. 30
60325 Frankfurt del Main
Alemanya
Please refer to the product packaging or purchase documentation for specific warranty terms and conditions.





