The Dot library provides a LoRaWan certified stack for LoRa communication using MultiTech mDot and xDot devices. The stack is compatible with mbed 5.

The name of the repository can be used to determine which device the stack was compiled for and if it's a development or production-ready build:

• libmDot-mbed5 -> production-ready build for mDot
• libmDot-dev-mbed5 -> development build for mDot
• libxDot-mbed5 -> production-ready build for xDot
• libxDot-dev-mbed5 -> development build for xDot

A changelog for the Dot library can be found here.

The Dot library version and the version of mbed-os it was compiled against can both be found in the commit message for that revision of the Dot library. Building your application with the same version of mbed-os as what was used to build the Dot library is highly recommended!

The Dot-Examples repository demonstrates how to use the Dot library in a custom application.

The mDot and xDot platform pages have lots of platform specific information and document potential issues, gotchas, etc, and provide instructions for getting started with development. Please take a look at the platform page before starting development as they should answer many questions you will have.

FOTA¶

Full FOTA support is only available with mDot, xDot does not have the required external flash. xDot can use the FOTA example to dynamically join a multicast session only. After joining the multicast session the received Fragmentation packets could be handed to a host MCU for processing and at completion the firmware can be loaded into the xDot using the bootloader and y-modem. See xDot Developer Guide.

• Add the following code to allow Fota to use the Dot instance

    // Initialize FOTA singleton
    Fota::getInstance(dot);

• Add fragmentation handling the the PacketRx event

    virtual void PacketRx(uint8_t port, uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr, lora::DownlinkControl ctrl, uint8_t slot, uint8_t retries, uint32_t address, bool dupRx) {
        mDotEvent::PacketRx(port, payload, size, rssi, snr, ctrl, slot, retries, address, dupRx);

#if ACTIVE_EXAMPLE == FOTA_EXAMPLE
        if(port == 200 || port == 201 || port == 202) {
            Fota::getInstance()->processCmd(payload, port, size);
        }
#endif
    }

A definition is needed to enable Fragmentation support on mDot and save fragments to flash. This should not be defined for xDot and will result in a compiler error.

{
    "macros": [
        "FOTA=1"
    ]
}

The FOTA implementation has a few differences from the LoRaWAN Protocol

• Fragmentation Indexing starts at 0
• McKEKey is 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
• Start Time is a count-down in seconds to start of session