addon Module Configuration

The addon module lets the Alemca Agent communicate with external software.
It is meant for uncommon protocols or highly specific systems.
An addon is a Lua module that interacts with the external software through function calls, and the link between the agent and the software is handled over gRPC, providing secure and efficient communication.

Addon Configuration

The Alemca agent is configured through a YAML file.
To declare an addon, add the following section to the agent’s configuration file:

iot:
  modules:
    addon:
      - name: can                  # Unique addon name (no spaces or special chars)
        addonType: can             # Addon type (here: CAN)
        address: "127.0.0.1:50051" # IP:PORT where the addon listens
        timeout: 5                 # Connection timeout in seconds
        useTLS: false              # true = enable TLS, false = plaintext

Configuration Details

• name : | Addon instance name. Must be unique with no spaces or special characters.
• addonType : Addon type (e.g., can for the CAN addon).
• address :Addon address in IP:PORT form.
• timeout :Connection timeout (seconds). The connection fails if it takes longer.
• useTLS : Whether to use TLS (true) or not (false). If you enable TLS, make sure the addon accepts TLS links

Configuration Example

From Lua you can access the addon as follows.
Calls are specific to the addon type; for a CAN addon you might use:

local can = require("can")

-- Connect to the CAN addon
local ok, err = can.connect()
if not ok then
    printError("Error connecting to CAN addon: " .. err)
    return
end

-- Get parsed DBC data (list of messages and signals)
local resp, err = can.call("GetDBCData")
--[[
[{
    "id" = 1,
    "name" = 2,
    "dlc" = 3,
    "signals" = [{
        "name"      = 1,
        "startBit"  = 2,
        "length"    = 3,
        "factor"    = 4,
        "offset"    = 5,
        "isSigned"  = 6,
        "isIntel"   = 7,
    }]
}]
]]

-- Stream of CAN frames with decoded signal values
local resp, err = can.call("SubscribeFrames")
--[[
{
  "id"    = 1,
  "name"  = 2,
  "dlc"   = 3,
  "signals" = [{
      "name"  = 1,
      "value" = 2,
  }]
}
]]

-- Latest decoded signal values from the last CAN frame
local resp, err = can.call("GetCurrentSignalValues")
--[[
[{
  "id"    = 1,
  "name"  = 2,
  "dlc"   = 3,
  "signals" = [{
      "name"  = 1,
      "value" = 2,
  }]
}]
]]

-- Disconnect from the CAN addon
local ok, err = can.disconnect()
if not ok then
    printError("Error disconnecting from CAN addon: " .. err)
    return
end

Associated Lua Fields

Field	Description
addon.name	Returns the addon instance name.
addon.type	Returns the module type (can, etc.).