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

Dot Library versions 3.x.x require a channel plan to be injected into the stack. Channel plans are included with the 3.x.x Dot Library releases. The following code snippet demonstrates how to create a channel plan and inject it into the stack.

#include "mDot.h"
#include "channel_plans.h"
 
int main() {
    ChannelPlan* plan = new lora::ChannelPlan_US915();
    assert(plan);
    mDot* dot = mDot::getInstance(plan);
    assert(dot);
                   
    // ...
}

Dot devices must not be deployed with software using a different channel plan than the Dot's default plan! This functionality is for development and testing only!

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 Example

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 and multicast 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/Multicast implementation is compatible with the v1 specifications provided by LoRa Alliance

• LoRaWAN Fragmentation Protocol
• LoRaWAN Multicast Setup Protocol
• Default GenAppKey is 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00