AT command firmware for MultiTech Dot devices.

Fork of mDot_AT_firmware by MultiTech

Dot Library Not Included!

Because these example programs can be used for both mDot and xDot devices, the LoRa stack is not included. The libmDot library should be imported if building for mDot devices. The libxDot library should be imported if building for xDot devices. The AT firmware was last tested with mbed-os-5.4.7. Using a version past mbed-os-5.4.7 will cause the build to fail. The library used with the AT firmware has to match the mbed-os version.

Dot Library Version 3 Updates

Dot Library versions 3.x.x require a channel plan to be injected into the stack. The Dot-Examples and Dot-AT-Firmware do this by defining a macro called "CHANNEL_PLAN" that controls the channel plan that will be used in the examples. Available channel plans will be in the Dot Library repository in the plans folder.

Revision 20 and earlier of Dot-Examples and revision 15 and earlier of Dot-AT-Firmware should be used with Dot Library versions prior to 3.0.0.

Fota Library

Th Fota Library must be added to compile for mDot 3.1.0 with Fota support. Latest dev libraries and 3.2.0 release will include Fota with libmDot/libxDot.

AT Firmware Description

This AT Firmware is what ships on mDot and xDot devices. It provides an AT command interface for using the mDot or xDot for LoRa communication.

AT command documentation can be found on

The firmware changelog can be found here. The library changelog can be found here.

Dot Libraries

Dot Library Limitations

The commit messages in libmDot-mbed5 and libmDot-dev-mbed5 specify the version of the Dot library the commit contains and the version of mbed-os it was compiled against. We recommend building your application with the version of mbed-os specified in the commit message of the version of the Dot library you're using. This will ensure that you don't run into any runtime issues caused by differences in the mbed-os versions.

Stable and development libraries are available for both mDot and xDot platforms. The library chosen must match the target platform. Compiling for the mDot platform with the xDot library or vice versa will not succeed.

mDot Library

Development library for mDot.


Stable library for mDot.

Import librarylibmDot-mbed5

Stable version of the mDot library for mbed 5. This version of the library is suitable for deployment scenarios. See lastest commit message for version of mbed-os library that has been tested against.

xDot Library

Development library for xDot.


Stable library for xDot.

Import librarylibxDot-mbed5

Stable version of the xDot library for mbed 5. This version of the library is suitable for deployment scenarios.


Jason Reiss
4 months ago

File content as of revision 33:5c0252521669:

#ifndef ATSERIAL_H
#define ATSERIAL_H

#include "mbed.h"

namespace mts

/** This class wraps provides a buffered wrapper to the mbed::UnbufferedSerial
 * class.  Looks for an escape sequence within received byte stream.
class ATSerial : private mbed::NonCopyable<ATSerial>
    /** Creates a new ATSerial object that can be used to talk to an mbed serial port
    * through internal SW buffers.  Providing RTS and CTS will enable flow control.
    * @param txd the transmit data pin on the desired mbed Serial interface.
    * @param rxd the receive data pin on the desired mbed Serial interface.
    * @param rts the request-to-send pin on the desired mbed Serial interface.
    * @param cts the clear-to-send pin on the desired mbed Serial interface.
    * @param baud The initial baudrate
    ATSerial(PinName txd, PinName rxd, PinName rts = NC, PinName cts = NC,

    /** Destructs an ATSerial object and frees all related resources, including
    * internal buffers.
    virtual ~ATSerial();

    /** This method is used to the set the baud rate of the serial port.
    * @param baudrate the baudrate in bps as an int. The default is 9600 bps.
    void baud(int baudrate);

    /** This method sets the transmission format used by the serial port.
    * @param bits the number of bits in a word (5-8; default = 8)
    * @param parity the parity used (SerialBase::None, SerialBase::Odd, SerialBase::Even,
    * SerialBase::Forced1, SerialBase::Forced0; default = SerialBase::None)
    * @param stop the number of stop bits (1 or 2; default = 1)
    void format(int bits=8, mbed::SerialBase::Parity parity=mbed::SerialBase::None, int stop_bits=1);

    /** Check if bytes are available to read.
     * @return True if receive buffer is not empty.
    bool readable();

    /** Check if bytes can be written.
     * @return True if transmit buffer is not full.
    bool writeable();

    /** Clear the receive buffer. */
    void rxClear();

    /** Clear the transmist buffer. */
    void txClear();

    /** Check for escape sequence detected on serial input
     * @return true if escape sequence was seen
    bool escaped();

    /** Set escape character. */
    void escapeChar(char esc);

    /** Get the escape character. */
    char escapeChar();

    /** Clear escaped state. */
    void clearEscaped();

    /** Read a byte from receive buffer
     * @param[out] c Storage for read character 
     * @return True if a character was read
    bool read(char& c);

    /** Read bytes from the receive buffer.
     * @param[out] buffer Allocated memory to store read bytes
     * @param length Size of buffer in bytes
     * @return Number of bytes read
    int read(char *buffer, size_t length);

    /** Write bytes from to transmit buffer.
     * @param buffer Bytes to write
     * @param length Size of buffer in bytes
     * @return Number of bytes written
    int write(const char *buffer, size_t length);

    /** Write formatted string to transmit buffer.
     * @param format Format string
     * @param ... Items to format
     * @return Number of bytes written
    int writef(const char* format, ... );

    mbed::UnbufferedSerial _serial; // Using unbuffered serial so reads can be done in event handler

    // Receive buffer
    mbed::CircularBuffer<char, MBED_CONF_DRIVERS_UART_SERIAL_RXBUF_SIZE> _rxbuf;
    // Transmit buffer
    mbed::CircularBuffer<char, MBED_CONF_DRIVERS_UART_SERIAL_RXBUF_SIZE> _txbuf;
    bool _tx_irq_enabled;   // Flag indicating transmit IRQ is enabled

    Timer _timer;           // Inter-byte receive timer
    std::chrono::milliseconds _last_time;   // Last time a byte was received
    int _esc_cnt;           // Number of escape characters received
    char _esc_ch;           // Escape character
    bool _escaped;          // True if escape sequence has been received
    void handleRead();      // Method for handling data to be read
    void handleWrite();     // Method for handling data writes
    void startWrite();      // Method for starting data writes
    PlatformMutex _mutex;   // Lock for API accesses
    bool _flow;             // Flag indicates flow control is enabled
    DigitalOut _rts;        // Request to send signal
    InterruptIn _cts;       // Clear to send signal
    size_t _hwm;            // RX buffer high water mark for setting RTS to stop
    size_t _lwm;            // RX buffer low water mark for setting RTS to start


#endif /* ATSERIAL_H */