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Bluetooth RS232 Serial Firefly Pair


MPN: RN-240F, RN-240M

Delivery: Ships same or next business day

Availability: in stock

30 day Money Back Guarantee *Some Exceptions Apply

Warranty: 1 year Comprehensive support for all products

Our Firefly Pair can replace your serial RS232 cable with a Bluetooth Class 1 wireless connection up to 100 meters (330 feet) away. Just plug them in, set the baud rate DIP switches, configure the jumpers for DTE or DCE, and you are connected!

No software changes or drivers required!


  • 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
  • Plastic housing
  • OEM versions available
Characters t 7 or 8 data bits
Connection modes Master, Slave, Instant Cable Replacement
Connectors Serial: DB9 - DTE (male) or DCE (female)
Control signals CTS, RTS
Data rates t 1200, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, 115.2k, 230k
Dimensions 3.0" x 1.3" x 0.9"
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
Mpn RN-240F, RN-240M
Parity odd, even, none
Power consumption
  • Idle: 1-10 ma
  • Connected: 30-50 ma
Product 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
Profiles Serial Port Profile (SPP)
Protocols Bluetooth Specification 2.0 (with high EDR data rate!), compatible with 1.1 and 1.2
Radio Class 1 Bluetooth (up to 100 meters)
Security/Protection FHSS (Frequency Hopping Spread Spectrum)
Serial interfaces 374,373
Serial types 372
Stop bits 1 or 2
Storage specifications Temperature: -40°C to +85°C (-40°F to +185°F)
Temperature range Operating: -40°C to +70°C - All components rated at this range or better.


Firefly Data Sheet View (PDF)
Firefly User Guide View (PDF)
Application Note – Using a Firefly with Siemens DDC Controllers View (PDF)

Tech Support

We have the best technical support engineers that know how to use our products. If our Tech Support cannot solve your problem, we will contact the design engineer or manufacturer to help find a resolution.