The SparkFun BlueSMiRF v2 with headers is a wireless Bluetooth® serial link. These boards work as a wireless serial UART pipe and are a great wireless replacement for serial cables. Simply pair, connect, and transmit serial data between your TX/RX lines! Any serial stream from 2400 to 921600 baud can be passed seamlessly between two devices.

Duplex transmissions up to 921600bps are supported. What does this mean? You can throw a book at each BlueSMiRF, which will correctly buffer, transmit, and deliver the data streams, byte perfect, to both radios.

BlueSMiRF v2 has a multitude of exciting improvements over the original. The BlueSMiRF pinout is the same as previous Bluetooth Mates and USB-to-serial converters (i.e., FTDI, CH340, etc.), making it extremely easy to hook up to many common Arduino development boards and high-precision GNSS breakout boards. The board can be connected directly with an Arduino Pro, Pro Mini, LilyPad Arduino 328 Main, ZED-F9P, ZED-F9R, UM980, SerLCD, or any board with a standard 6-pin serial connector. This version of the board includes a row of 1x6 male, right-angle headers. BlueSMiRF can be connected to a 1x6 female header attached to the target board or used in a breadboard. The SparkFun BlueSMiRF v2 is perfect for short-range applications up to 100ft (33m) indoors that require easy to setup, point-to-point communication.

A BlueSMiRF can be connected to a phone or computer to view data or remote control easily. Two BlueSMiRFs can also be easily connected using the onboard PAIR button. If needed, this button can be disabled by cutting the jumper on the back of the board.

We've designed the BlueSMiRF to be remotely configured from a phone using a serial terminal app. Changing the settings, such as the baud rate, flow control, and LED mode, is easily done using the simple AT command set. Additionally, Over The Air (OTA) updates using WiFi allow easy in-field firmware updates as new features are released.

The BlueSMiRF v2 has an on-board voltage regulator to power between 3.3V and 5V. Logic level shifting circuitry is included on all pins to be 3.3V to 5V tolerant. Note that you will need an RS232 to TTL converter for higher voltages. A jumper on the top of the board is also included to bypass the voltage regulator. Two built-in LEDs indicate when the BlueSMiRF is connected and when there is serial UART traffic.

Note: Bluetooth® classic (Serial Port Profile or SPP) is primarily supported. This Bluetooth protocol is supported on Android phones, most desktops, and laptops. BlueSMiRF also supports the BLE protocol, available on all Apple phones.

• Espressif's ESP32-PICO-MINI-02 Module with Built-in PCB Antenna
• Serial Bluetooth® Point-to-Point Communication
• Bluetooth Protocols Supported
  • Serial Port Profile (SPP)
  • Bluetooth Low Energy (BLE)
• Firmware Over-the-Air (OTA) Updates via 2.4GHz WiFi
• Recommended Input Voltage: 3.3V to 5V
• Current & Power Consumption @ 3.3V
  • Idle: 72mA / 238mW
  • Connected with no Serial Traffic: 75mA / 248mW
  • Constant Duplex Serial Traffic: 140mA / 462mW
• AP2112K 3.3V/600mA Voltage Regulator
• Logic Level Converters on all pins
• Standard Serial Port with Built-in Right Angle Male Headers
  • RTS/RXI/TXO/VCC/CTS/GND
• PTH
  • Reset
• Button
  • Pair
• LEDs
  • CONNECT
  • STATUS
• Jumpers
  • 3.3V Bypass Jumper (JP2)
  • Pair Button (BTN)
• Pre-soldered Headers
• Weight: 3.40g
• Board Dimensions
  • 44.2mm x 15.22mm

• Schematic
• KiCad Files
• 3D Model
• Board Dimensions
• Hookup Guide
• Datasheet (ESP32-PICO-MINI-02)
• Firmware
• GitHub Hardware Repo