OSOLINK WiFi/BLE I/O Shield v1.0 – Product Introduction

1. Product Overview

The OSOLINK WiFi/BLE I/O Shield v1.0 is a wireless communication expansion board designed for Arduino Uno, Arduino Mega 2560, and other Arduino-compatible development boards that use the standard Arduino pin layout. It is built around the Espressif ESP32-C3-MINI-1-N4 module, which integrates a single-core RISC-V processor running at up to 160 MHz, 4 MB of built-in flash, IEEE 802.11 b/g/n Wi-Fi, and Bluetooth 5.0 (BLE) in a compact SMD package.

Unlike previous generation shields that used the ESP8266, the ESP32-C3 offers a significantly upgraded feature set: dual-mode wireless (Wi-Fi + BLE simultaneously), enhanced security (WPA3, TLS 1.3), more GPIOs, and built-in USB Serial/JTAG for easier development. The shield communicates with the host Arduino via UART, using a configurable UART Selector jumper that lets you choose between the hardware serial port (D0/D1) or a software serial port (D4/D5), avoiding conflicts with the Arduino’s programming interface.

The board also provides a 2.54 mm female header interface for connecting an external MPU-6050 module (I2C, 5 V, and GND lines are pre-wired to the corresponding Arduino pins), a power switch with external VIN input, an IR interface, and clearly labeled breakout pins for quick prototyping. All logic operates at 3.3 V internally, with on-board level conversion protecting the ESP32-C3 from the Arduino’s 5 V signals.

2. Target Areas

The OSOLINK WiFi/BLE I/O Shield v1.0 is primarily designed for the following application domains:

2.1 Robot Car & Autonomous Vehicle Control

• Remote control over Wi-Fi / BLE: Send speed and direction commands from a smartphone app or web dashboard to an Arduino-based motor driver shield.
• Telemetry reporting: Stream real-time sensor data (speed, battery voltage, distance) back to a host PC or mobile device.
• OTA firmware update: Update the Arduino sketch logic via Wi-Fi without physical access to the robot.
• IMU-assisted navigation: Plug an external MPU-6050 module into the on-board 2.54 mm header to obtain acceleration and gyroscope data for self-balancing robots or heading-hold functions.
• Multi-robot coordination: Use BLE mesh networking for low-latency communication and formation control between multiple robots.

2.2 IoT (Internet of Things) Projects

• MQTT sensor node: Connect temperature, humidity, gas, or light sensors to the Arduino and publish readings to an MQTT broker (e.g., Mosquitto, AWS IoT, Alibaba Cloud IoT).
• HTTP / RESTful API client: Push sensor data to cloud platforms such as ThingSpeak, Blynk, or a custom server using HTTP GET/POST requests.
• Smart home control: Integrate with Home Assistant or other home-automation platforms over Wi-Fi; use BLE for proximity-based device wake-up.
• Edge gateway: Use the ESP32-C3 as a lightweight pre-processing node that aggregates data from multiple Arduinos and forwards structured JSON payloads to a cloud backend.
• BLE beacon / scanner: Implement iBeacon advertising or scan for BLE peripherals (heart-rate monitors, environmental tags) and relay data to an Arduino application.

3. Features

• Based on Espressif ESP32-C3-MINI-1-N4: 160 MHz RISC-V single-core, 4 MB Flash, integrated Wi-Fi 4 (802.11 b/g/n, 2.4 GHz) and Bluetooth 5.0 BLE.
• Fully compatible with Arduino Uno and Arduino Mega 2560 form factor and pin layout — plug and play.
• UART-based communication with host Arduino — no custom library needed; works with standard Serial / SoftwareSerial and AT-command firmware.
• UART Selector jumper: switch the ESP32-C3 UART0 connection between Arduino hardware serial (D0/D1) and an alternate port (D4/D5), preventing USB-programming conflicts.
• On-board 3.3 V level conversion protects the ESP32-C3 I/O from 5 V Arduino signals on the UART lines.
• MPU-6050 module interface: 2.54 mm female header for connecting an external MPU-6050 module; I2C (SDA/SCL), 5 V, and GND lines are pre-connected to the corresponding Arduino pins.
• On-board IR interface for infrared remote control transmission or reception.
• Power switch with external VIN input via JST connector — enables battery-powered operation without removing the shield.
• Dedicated EN (S1) and BOOT (S2) buttons for ESP32-C3 reset and boot-mode selection.
• Reserved ESP UART0 interface (unpopulated — no headers soldered by default) for direct firmware flashing of the ESP32-C3; solder a 2.54 mm header or use pogo pins when needed.
• Breakout pads for IO18 and IO19 — additional ESP32-C3 GPIOs for custom peripherals.
• Power indicator LED and full Arduino-layout through-hole pin headers.
• Compact purple PCB with clear silkscreen labeling; standard Arduino shield dimensions.

4. Specifications

4.1 Wireless Module – ESP32-C3-MINI-1-N4

4.2 Shield Electrical Characteristics

4.3 MPU-6050 Module Interface

The shield provides a 2.54 mm pitch female header for plugging in an external MPU-6050 module (sold separately). The I2C, 5 V, and GND lines are pre-wired to the Arduino’s corresponding pins. The table below lists the typical specifications of a compatible MPU-6050 module for reference.

5. Component Description

Fig. 2 – 2D PCB Layout with component labels

The table below describes the major components on the OSOLINK WiFi/BLE I/O Shield v1.0 as they appear on the PCB.

Fig. 3 – Circuit Schematic (SCH_OSOLINK WiFi-BLE I/O Shield v1.0)

6. Mechanical Information

Fig. 4 – PCB 2D Dimension Drawing

7. Related Documents

8. Precautions & Notes

Warning: Always power off the Arduino before inserting or removing this shield. Hot-plugging may damage both the shield and the host board.

1. Logic level — do not connect 5 V signals directly to ESP32-C3 GPIO pins.
The ESP32-C3 I/O operates at 3.3 V. On-board level conversion is provided for the UART lines only. Avoid connecting other 5 V signals directly to the IO18/IO19 breakout pads or the ESP module without additional external level shifters.

2. UART Selector setting during Arduino sketch upload.
If the UART Selector is set to the Hardware Serial (D0/D1) position, uploading a new sketch to the Arduino via USB will fail because D0/D1 are shared. Switch the jumper to the alternate (D4/D5) position before uploading, then switch back after programming is complete.

3. ESP32-C3 firmware flashing via the ESP UART0 interface.
The shield ships with Espressif AT firmware by default. The ESP UART0 interface is reserved for firmware flashing but has no headers or sockets soldered by default. To reflash: first solder a 2.54 mm header or use pogo pins on the ESP UART0 pads; connect a 3.3 V USB-to-UART adapter; hold BOOT (S2) and press EN (S1) to enter download mode; then run esptool or ESP Flash Download Tool.

4. I2C address conflict (MPU-6050 module).
A plugged-in MPU-6050 module occupies I2C address 0x68 (AD0 = GND, default on most breakout modules) on the Arduino I2C bus (A4/A5). Ensure no other device on the same bus shares this address. If a conflict exists, pull the AD0 pin of the MPU-6050 module high (connect AD0 to 3.3 V on the module itself) to switch its address to 0x69.

5. Power consumption.
During active Wi-Fi transmission the ESP32-C3 can draw up to 350 mA peak. Ensure the Arduino host’s 5 V rail or external VIN source can supply sufficient current. For sustained wireless operation, use an external power source via the VIN JST connector rather than relying solely on the Arduino’s USB power.

6. Antenna keep-out area.
The ESP32-C3-MINI-1 has a PCB trace antenna extending from one end of the module. Avoid placing metallic objects or wiring directly above or beside this antenna area to maintain optimal RF performance.

7. Operating temperature.
Do not operate the shield in environments exceeding 70 °C or below -20 °C. The AMS1117 LDO regulator generates heat under heavy load; ensure adequate ventilation in enclosed enclosures.

8. ESD precautions.
Handle the board using standard ESD precautions (grounded wrist strap, anti-static mat). The ESP32-C3 module is sensitive to electrostatic discharge.

OSOLINK WiFi/BLE I/O Shield v1.0  |  Designed by OSOYOO  |  www.osoyoo.com
Document version: 1.0  |  Last updated: 2026-05-14