The xDot adapter provides the ability for the ClearBlade platform to communicate with a MultiTech MultiConnect xDot device (https://www.multitech.com/models/94558032LF). The MultiConnect xDot is a LoRaWAN, low-power RF device. Interacting with the xDot is done through the use of AT commands (https://www.multitech.com/documents/publications/manuals/s000643.pdf).

As currently written, the xDot adapter enables peer-to-peer (http://www.multitech.net/developer/software/mdot-software/peer-to-peer/) communications with other xDot devices. Peer-to-peer mode provides the ability to create a mesh network of LoRa enabled devices. In additon, the xDot adapter enables serial data mode on the xDot device in order to transmit and receive data in peer-to-peer mode.

The adapter subscribes to MQTT topics which are used to interact with the xDot. The adapter publishes any data retrieved from the xDot to MQTT topics so that the ClearBlade Platform is able to retrieve and process xDot related data or write data to xDot devices.

The xDot adapter utilizes MQTT messaging to communicate with the ClearBlade Platform. The xDot adapter will subscribe to a specific topic in order to handle xDot device requests. Additionally, the xDot adapter will publish messages to MQTT topics in order to communicate the results of requests to client applications. The topic structures utilized by the xDot adapter are as follows:

• Read xDot data request: {TOPIC ROOT}/receive/request
• Read xDot data response: {TOPIC ROOT}/receive/response
• Write xDot data request: {TOPIC ROOT}/send/request

The xDot adapter was constructed to provide the ability to communicate with a System defined in a ClearBlade Platform instance. Therefore, the adapter requires a System to have been created within a ClearBlade Platform instance.

Once a System has been created, artifacts must be defined within the ClearBlade Platform system to allow the adapters to function properly. At a minimum:

• A device needs to be created in the Auth --> Devices collection. The device will represent the adapter, or more importantly, the xDot device or MultiTech Conduit gateway on which the adapter is executing. The name and active key values specified in the Auth --> Devices collection will be used by the adapter to authenticate to the ClearBlade Platform or ClearBlade Edge.
• An adapter configuration data collection needs to be created in the ClearBlade Platform system and populated with the data appropriate to the xDot adapter. The schema of the data collection should be as follows:

The adapter_settings column will need to contain a JSON object containing the following attributes:

• 4 bytes of hex data using a colon (:) to separate each byte from the next byte
• Must be identical on all xDots in order for peer-to-peer mode to function

• 16 bytes of hex data using a colon (:) to separate each byte from the next byte
• Must be identical on all xDots in order for peer-to-peer mode to function

• 16 bytes of hex data using a colon (:) to separate each byte from the next byte
• Must be identical on all xDots in order for peer-to-peer mode to function

• The full unix path to the xDot serial device (ex. /dev/ttyAP1)

• DR0-DR15 can be used
• See https://www.multitech.com/documents/publications/manuals/s000643.pdf for further information

• The transmit frequency to use in peer-to-peer mode
• Use 915.5-919.7 MhZ for US 915 devices to avoid interference with LoRaWAN networks

{
"networkAddress":"00:11:22:33",
"networkDataKey":"33:22:11:00:33:22:11:00:33:22:11:00:33:22:11:00",
"networkSessionKey":"00:11:22:33:00:11:22:33:00:11:22:33:00:11:22:33",
"serialPortName":"/dev/ttyAP1",
"transmissionDataRate":"DR8",
"transmissionFrequency":"915500000", "antennaGain": "0", "transmitPower": "20" }

xDotAdapter -systemKey=<SYSTEM_KEY> -systemSecret=<SYSTEM_SECRET> -platformURL=<PLATFORM_URL> -messagingURL=<MESSAGING_URL> -deviceName=<DEVICE_NAME> -password=<DEVICE_ACTIVE_KEY> -adapterConfigCollectionID=<COLLECTION_ID> -logLevel=<LOG_LEVEL>

Where

systemKey

• REQUIRED
• The system key of the ClearBLade Platform System the adapter will connect to

systemSecret

• REQUIRED
• The system secret of the ClearBLade Platform System the adapter will connect to

deviceName

• The device name the adapter will use to authenticate to the ClearBlade Platform
• Requires the device to have been defined in the Auth - Devices collection within the ClearBlade Platform System
• OPTIONAL
• Defaults to xDotSerialAdapter

password

• REQUIRED
• The active key the adapter will use to authenticate to the platform
• Requires the device to have been defined in the Auth - Devices collection within the ClearBlade Platform System

platformUrl

• The url of the ClearBlade Platform instance the adapter will connect to
• OPTIONAL
• Defaults to http://localhost:9000

messagingUrl

• The MQTT url of the ClearBlade Platform instance the adapter will connect to
• OPTIONAL
• Defaults to localhost:1883

adapterConfigCollectionID

• REQUIRED
• The collection ID of the data collection used to house adapter configuration data

logLevel

• The level of runtime logging the adapter should provide.
• Available log levels:
  • fatal
  • error
  • warn
  • info
  • debug
• OPTIONAL
• Defaults to info

The xdot adapters are dependent upon the ClearBlade Go SDK and its dependent libraries being installed. The xDot adapter was written in Go and therefore requires Go to be installed (https://golang.org/doc/install).

In order to compile the adapter for execution within mLinux, the following steps need to be performed:

1. Retrieve the adapter source code
   • git clone git@github.com:ClearBlade/xDot-Adapter.git
2. Navigate to the xdotadapter directory
   • cd xdotadapter
3. Compile the adapter
   • GOARCH=arm GOARM=5 GOOS=linux go build