MTS Dragonfly

The MultiConnect® Dragonfly offers developers an FCC and carrier certified solution that makes connecting sensors and other edge-of-network devices quick and easy.


The MultiConnect® Dragonfly™ cellular SoMs are complete, ready-to-integrate processing and communications devices that offer developers the functionality of a SoM with the convenience of an onboard cellular radio all in one compact design. With its integrated Cortex M4 processor, developers can host their application and have access to a full suite of interfaces for connecting sensors or other remote assets.

Dragonfly also comes with an ARM mbed compatible software library for even faster development. This powerful suite of hardware and software products greatly reduces your time to market and makes your Internet of Things (IoT) device a reality today.

Key Benefits


Offline Development Options

It is possible to develop offline for the Dragonfly using mbed-cli and the Eclipse IDE. See our wiki page for more information.

Developer Kit Required

To program and use the Dragonfly, you will need a UDK2 Developer Kit.

Dragonfly Pinout Diagram


The pinout diagram above shows the commonly used interfaces and their locations. In addition to their stated functions, all GPIO pins (PA_*, PB_*, PC_*) can also be used as DigitalIn and DigitalOut interfaces.

InterruptIn Limitations

Due to the processor's architecture, only one pin of the same number (e.g. PA_1 & PB_1) may be configured as an InterruptIn. If multiple pins of the same number are configured as InterruptIn, only the last pin configured will actually trigger an interrupt in the processor. The rest will be ignored.

PwmOut Limitations

PwmOut objects using different channels of the same timer must use the same prescaler value. Each timer has a single prescaler which applies to all channels in the timer.

For STM32F411 devices, two possible prescaler values are allowed:

  • 1us which allows for a period/pulse from 1us to 65535us
  • 500us which allows for a period/pulse from 500us to 32.76s

5V Tolerant IO Limitations

If the external voltage on a GPIO is greater than VDD + 0.3V, use of the internal pullup or pulldown resistors could damage the mDot. External pullup or pulldown resistors should be used instead.

For more information see the notes below section 6.3.1 of the STM32F411RE Data Sheet.

Dragonfly Features

Cellular Stack (MTSCellularInterface)

The MTSCellularInterface library implements the mbed-os CellularInterface for the cellular radios on MultiTech Dragonfly devices. MTSCellularInterface provides TCP and UDP sockets, SMS messaging capabilities, and GPS location*. After cloning this repository, run the setup script ( or setup.bat) to generate the version header and clone required dependencies. The library can be cloned from GitHub.

* Not all radios support GPS. GPS location requires a lock on GPS satellites, which may not be possible indoors.

Example Programs

Import our example programs to get up and running quickly and easily, then modify them to create your own solution using the Dragonfly!

Most radios require an APN string to be set before the radio can be used. The APN can be set in the source of the specific example you're using. The SMS example also needs a phone number to send/receive SMS messages to/from.

Import programDragonfly-Examples

Example programs for MultiTech Dragonfly devices demonstrating how to use the MultiTech MTSCellularInterface library for cellular radio communication and control.

Old Cellular Stack (MTSAS)

This old cellular stack is not compatible with mbed-os. Consider using MTSCellularInterface instead!

Import librarymtsas

Complete library supporting MultiConnect Dragonfly and SocketModem Arduino Shield devices.

Old Example Programs

These old example programs use the deprecated MTSAS library which is not compatible with mbed-os. Consider using Dragonfly-Examples and MTSCellularInterface instead!

Import programDragonfly_Cellular_Ping_Example

Ping a server using the onboard cellular radio.

Import programDragonfly_Cellular_SMS_Example

Send and receive SMS messages using the onboard cellular radio.

Import programDragonfly_Cellular_HTTP_Example

Does HTTP GET and POST requests using the onboard cellular radio.

Import programDragonfly_Cellular_HTTPS_Example

Does HTTPS GET and POST requests using the onboard cellular radio.

Factory Firmware

The Dragonfly ships from the factory pre-loaded with AT Passthrough Firmware. This firmware implements serial passthrough and provides direct access to the cellular radio via the external serial port on the UDK2. It is available here.

Offline IDE

It is possible to compile for the Dragonfly and debug them on the Dragonfly using the Eclipse IDE. See our wiki page for more information.

MTS Bootloader

The Dragonfly includes a bootloader which allows applications to be upgradet OTA (Over The Air) or via serial without the need for a developer board. See the wiki page describing how the bootloader can be used for more information.

Technical Reference


Data Sheets

Interface Firmware

The UDK2 uses the same ST-Link interface firmware as many of the ST Nucleo boards. The latest interface firmware and instructions for upgrading can be found here.

Getting Started with mbed

1. Connect your microcontroller to a PC

Use the USB lead to connect your mbed to a PC. The status light will come on, indicating it has power. After a few seconds of activity, the PC will recognise the mbed Microcontroller as a standard USB drive.

Windows XP exampleMac OS X example

Go to the new USB Drive, and click MBED.HTM to open it in a web browser.

If you do not have an mbed account, choose "Signup", and create your mbed Account. Otherwise, log in with your normal username and password.

This will give you access to the website, tools, libraries and documentation.

PC Configuration

Your mbed Microcontroller can appear on your computer as a serial port. On Mac and Linux, this will happen by default. For Windows, you need to install a driver:

Serial Driver for Debug Port on Windows

The DK boards for the mDot require the ST-Link driver to be installed before the debug serial port can be used on Windows PCs. This driver is different from the mbed Windows serial driver.

From a host PC to communicate with mbed you will need a terminal application. This allows the mbed Microcontroller to print to your PC screen, and for you to send characters back to your mbed.

Some terminal programs (e.g. TeraTerm) list the available serial ports by name. However, if you do need to know the identity of the serial port so that you can attach a terminal or an application to it:

Find the identity of the COM port by opening ''Device Manager''. To do this navigate ''Start -> Control Panel -> System -> Hardware -> Device Manager''.To find the device name under Mac OS X, use the command ''ls /dev/tty.usbmodem*''To find the device name under Linux, use the command ''ls /dev/ttyACM*''

On both Mac and Linux PCs, the port with the higher number will be the USB serial debug port. For example, if you have Linux and get ports /dev/ttyACM0 and /dev/ttyACM1, ttyACM1 will be the debug port and ttyACM0 the AT command/secondary port.

Downloading A program

1. Save a program binary (.bin) to the Platform

Download the appropriate "Hello World!" binary:

Note: the source code for this program will be seen in the next section.

Save the program binary file to your mbed Microcontroller Disk, just like you would with a normal USB disk. The Status LED will flash as the PC writes the file to the Microcontroller disk. The file is now consumed.

2. Press the Reset Button

When the Reset Button in pressed, the microcontroller will be reset and the last programmed application will begin to run.

3. Hello World!

The Microcontroller is now running the program; flashing LED1 forever! If you reset the Microcontroller, or disconnect and reconnect the power, the program will simply restart.

Hello World!

Import programmbed-os-example-blinky

This is a very simple guide, reviewing the steps required to get Blinky working on an mbed OS platform.

In its current state, the program will blink the D3 LED on a UDK2 board.

Where Next

Follow the guide to creating your own programs using the online compiler

Please log in to start a discussion or ask a question.


See more related questions