Bluetooth SMD Module - RN-42 (v6.15)

This is the RN-42 module from Roving Networks, a powerful, small, and very easy to use. This Bluetooth module is designed to replace serial cables. The Bluetooth stack is completely encapsulated. The end user just sees serial characters being transmitted back and forth. Press the 'A' character from a terminal program on your computer and an 'A' will be pushed out the TX pin of the Bluetooth module.

The RN-42 is a pin compatible substitution for the RN-41. The primary difference between the RN-42 and RN-41 is that the RN-42 is a Class 2 device meaning its range is about 50 to 60 feet and correspondingly the power consumption is reduced.

The RN-42 is perfect for short range, battery powered applications. The RN-42 uses only 26uA in sleep mode while still being discoverable and connectable. Multiple user configurable power modes allow the user to dial in the lowest power profile for a given application.

Supporting multiple Bluetooth profiles such as SPP and HID and simple UART hardware interface, it is simple to integrate into an embedded system or simply connect to an existing device. The RN-42 is FCC and Bluetooth SIG certified making it a complete embedded Bluetooth solution.

  • Fully qualified Bluetooth module
  • FCC Certified
  • Fully configurable UART
  • UART Data rates up to 3Mbps
  • Over air data rate of 721kbps to 2.0Mbps
  • Low power sleep mode
  • Compatible with all Bluetooth products that support SPP
  • Includes support for BCSP, DUN, LAN, GAP SDP, RFCOMM, and L2CAP protocols
  • 3.3V operation
  • Status pin
  • Bluetooth Technology v2.0 compatible
  • Class 2 power output

Bluetooth SMD Module - RN-42 (v6.15) Product Help and Resources

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Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

3 Soldering

Skill Level: Competent - You will encounter surface mount components and basic SMD soldering techniques are required.
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Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

3 Electrical Prototyping

Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
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Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Raveious / about 7 years ago / 1

    This radio would be great for a project of mine that I'm trying to get completed. I really like this module because it doesn't just have SPP but HID as well. One thing that I noticed is that the gamepad configuration only has support for 4 axes? Is there a bluetooth radio out there that supports 5 instead?

  • RobotRacer / about 9 years ago / 1

    I am trying to pass FCC/ IC and CE testing. Part of the process is the Spurious Emissions test. I am trying to contact the manufacturer to figure out how to control which channel the device is broadcasting on (need to select highest frequency and lowest frequency). Does anyone here know how it could be done?


  • Member #712441 / about 9 years ago / 1

    I'm looking to use RN-42's to replace two HC-05's acting as a 'serial cable'. This is a fairly 'mission-critical' serial link (sensors pushing data to a flight-computer). One of the problems I experienced with the HC-05 serial connection was that a cellphone with its Bluetooth enabled 'broke' the serial connection if it was brought too close to the modules. Will the R-42's in a Master/Slave configuration ignore all other Bluetooth signals? It would be ok for the modules to respond to Bluetooth 'interference', just so long as they don't break the established Master/Slave serial connection to do it!


  • YusefHD / about 9 years ago / 1

    From what I've read from all over, this is an incredibly reliable module. Here's the part, if you'd like to build something with it in browser!

  • LAM8 / about 10 years ago / 1

    Can I use this on a Flora?

    • M-Short / about 10 years ago / 1

      While we are not too familiar with the Flora probably not. This is just a modules meaning you would need to soldering to a board to be able to attach any components (like power). Also, as far as I know the Flora does not support Bluetooth. If you have any other questions please email

  • I bought this module and can't seem to get into command mode. I have tried every thing i can think of including: using a uC(atmega), connecting through Bluetooth(XP,Win7,android), and USB rs232 to TTL. Nothing seems to work. The module seems to just stay in SPP mode. I have probed the data to and from the device where possible with a logic analyzer to double check the baud rates and data. Does anyone have any similar issues with this module or could offer some suggestions? Model: RN-42 IC: 6514A-RN42 HID651

  • RocketGuy / about 10 years ago / 1

    Confused- it's non-HID and supports HID at the same time? Or bad copy/paste?

    • JeremyVnc / about 10 years ago / 3

      This is the non-HID firmware loaded version. I.e. This is the serial wire replacement. It can still be loaded with the HID firmware at a later date using the SPI interface.

      • gskelly / about 10 years ago / 3

        Actually, since this includes the v6.15 firmware, you don't need to re-flash the module to switch between HID and SPP. It can now be done using AT commands as follows:

        S~,6    // Enable HID on reboot
        R,1     // Reboot
        S~,0    // Enable SPP on reboot
        R,1     // Reboot

      • RocketGuy / about 10 years ago / 1

        Ahhh, got it. Thanks!

Customer Reviews

4 out of 5

Based on 3 ratings:

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1 of 1 found this helpful:

Performs as advertsied

With nearly no setup at all, the module performed as adverstised

1 of 1 found this helpful:

Works fine but doc could be clearer

It was a little difficult to understand the pinout since it is symmetrical and the doc doesn't say whether the view is top or bottom. Once it was hooked up correctly it worked fine.