Destination

Source: src/AWS/IoTWireless/Destination.ts

An AWS IoT Core for LoRaWAN destination — the routing rule that delivers uplink messages from wireless devices to an AWS IoT rule or MQTT topic.

The destination name is its identity (changing it replaces the destination); the expression, expression type, description, role, and tags all update in place.

Creating Destinations

Route uplinks to an IoT rule

import * as IoTWireless from "alchemy/AWS/IoTWireless";

const destination = yield* IoTWireless.Destination("Uplinks", {
  expressionType: "RuleName",
  expression: "process_sensor_uplinks",
  roleArn: deliveryRole.roleArn,
});

Publish uplinks straight to an MQTT topic

const destination = yield* IoTWireless.Destination("Uplinks", {
  expressionType: "MqttTopic",
  expression: "sensors/uplinks",
  roleArn: deliveryRole.roleArn,
});

Delivery Role

const deliveryRole = yield* IAM.Role("IotWirelessDelivery", {
  assumeRolePolicyDocument: {
    Version: "2012-10-17",
    Statement: [{
      Effect: "Allow",
      Principal: { Service: "iotwireless.amazonaws.com" },
      Action: ["sts:AssumeRole"],
    }],
  },
  policies: [{
    policyName: "deliver",
    policyDocument: {
      Version: "2012-10-17",
      Statement: [{
        Effect: "Allow",
        Action: ["iot:DescribeEndpoint", "iot:Publish"],
        Resource: ["*"],
      }],
    },
  }],
});

Consuming Uplinks in a Function

Uplinks are delivered through AWS IoT Core. For a RuleName destination, IoTWireless.consumeUplinks (see DestinationEventSource) creates the named IoT rule targeting the current Lambda and invokes the handler for every uplink. Alternatively, point an MqttTopic destination at a topic and consume it with AWS.IoT.consumeTopicMessages.

const destination = yield* IoTWireless.Destination("Uplinks", {
  expressionType: "RuleName",
  expression: "sensor_uplinks",
  roleArn: deliveryRole.roleArn,
});

// inside the Function effect (provide Lambda.WirelessDestinationEventSource):
yield* IoTWireless.consumeUplinks(destination, (uplinks) =>
  uplinks.pipe(
    Stream.runForEach((uplink) => processUplink(uplink)),
    Effect.orDie,
  ),
);