This product is discontinued and no longer available.

Suggested replacement: Serial to Bluetooth Adapter - GRIDBluFly

Serial to Bluetooth Adapter - Firefly

5.0 stars 5.0 (5) See customer reviews



Manufacturer: Grid Connect Inc.

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Product Information

Product Description

The Firefly is a Bluetooth to RS232 serial adapter. It attaches to a RS232 serial port making it a Bluetooth Class 1 wireless connection, capable of transmitting your serial data up to 100 meters (330 feet) away.

You can use the Bluetooth Firefly with another Firefly in "cable replacement mode" to make your RS232 cable wireless. The Firefly Bluetooth serial adapter may also be paired with any other Bluetooth device that supports Bluetooth SPP (Serial Port Profile). Note that many devices with built-in Bluetooth (e.g. PC's, Laptops, Handhelds and phones) utilize Bluetooth Class 2 radios, which only has a range up to 10 meters, so if you use a Firefly with a Class 2 device, you will only get the effective range of the Class 2 device and not the Firefly. 

The Firefly supports Bluetooth specification 2.0 (which provides faster Enhanced Data Rate (EDR) and lower Bit Error Rate (BER)), but is also compatible with devices supporting the older 1.x specifications.

The Firefly has dip switches to make set-up of the most common serial baud rates quick and easy. It also supports "AT" commands which allow you to change the firefly settings with messages sent through the serial port.




  • DIP switches for 9600/115200 Baud Rate (other baud rates available with AT commands), Auto Master, Auto Discover and factory reset
  • AT Commands for easy setup through serial port (use Windows Hyperterminal or similar)
  • No software or drivers required
  • OEM versions available
  • Plastic Housing

Documents and Drivers


Firefly Datasheet

Firefly User Guide

Application Note – Using a Firefly with Siemens DDC Controllers


Characters T

7 or 8 Data Bits

Connection Modes

Master, Slave, Instant Cable Replacement


Serial: DB9 - DTE (male) or DCE (female)

Control Signals


Data Rate

1200, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, 115.2k, 230k


3.0" x 1.3" x .9"

Flow Control

Hardware (RTS/CTS) or None

Included in Box

  • AC Power Adapter, 1A @ 5VDC (USB Power cable available)
  • CD with Manual

Indicators LED

  • Transmit/Receive (TX/RX) Data
  • Power
  • Connection Status


RN-240F, RN-240M


odd, even, none

Power Consumption

  • Idle: 1-10 ma
  • Connected: 30-50 ma

Power Supply

  • Pin 9 of serial DB9 connector - must be regulated to 4-11 VDC
  • Wall Supply: 5 VDC @ 1A, Plug size (1.3 x 3.5 x 9.5 mm)
  • USB Cable (draws power from USB Port)

Product Weight

0.6 oz - Approximate, Without Power Supply


Serial Port Profile (SPP)


Bluetooth Specification 2.0 (with high EDR data rate!), compatible with 1.1 and 1.2


Class 1 Bluetooth (up to 100 meters)


FHSS (Frequency Hopping Spread Spectrum) Security

Serial Interfaces


Serial Types


Stop Bits

1 or 2

Temperature Range

  • Storage: -40°C to +85°C (-40°F to +185°F)
  • Operating: -40°C to +70°C - All components rated at this range or better.

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