node-red-contrib-chirpstack-multicast

Node-RED node for sending multicast downlinks to ChirpStack v4 LoRaWAN network server.
This node was generated using claude.ai

Features

- ✅ Send multicast downlinks to groups of LoRaWAN devices
- ✅ Support for ChirpStack v4.x (gRPC API)
- ✅ Multiple data format support (Buffer, Hex, Base64, UTF-8)
- ✅ Cayenne LPP compatible
- ✅ Debug mode for troubleshooting
- ✅ Complete error handling

Installation

``bash
npm install node-red-contrib-chirpstack-multicast
`

Or install directly from Node-RED's palette manager.

Requirements

- Node-RED >= 2.0.0
- ChirpStack v4.x
- LoRaWAN devices in Class C mode
- Configured multicast group in ChirpStack

Configuration

$3

1. Drag the chirpstack-multicast node into your flow
2. Double-click to configure
3. Create a new server configuration:
- Server: Your ChirpStack server address (e.g., localhost:8080)
- API Token: Your ChirpStack API key

$3

- Name: Optional node name
- Server: Select your ChirpStack server
- Group ID: Multicast group ID (optional, can be provided via msg)
- fPort: LoRaWAN application port (default: 10)
- Debug: Enable debug logging

Usage

$3


`javascript
msg.multicastGroupId = "4820fc7f-0579-46a6-a67f-96d46e2c0cd7";
msg.fPort = 10;
msg.payload = "Hello World";
return msg;
`

$3

`javascript
msg.multicastGroupId = "4820fc7f-0579-46a6-a67f-96d46e2c0cd7";
msg.payload = Buffer.from([0x01, 0x02, 0x03, 0x04]);
return msg;
`

$3

`javascript
msg.payload = "48656C6C6F"; // "Hello" in hex
return msg;
`

$3

`javascript
// Temperature sensor (channel 1)
const buf = Buffer.alloc(4);
buf[0] = 1; // Channel
buf[1] = 0x67; // Temperature type
buf[2] = 0x01; // Value high byte (25.6°C)
buf[3] = 0x00; // Value low byte

msg.multicastGroupId = "your-group-id";
msg.payload = buf;
return msg;
`

$3


`javascript
function encodeCayenneLPP(temp1, temp2, hum1, hum2) {
const buf = Buffer.alloc(14);
let i = 0;

// Channel 1 - Temperature
buf[i++] = 1; buf[i++] = 0x67;
let t1 = Math.round(temp1 * 10);
buf[i++] = (t1 >> 8) & 0xFF;
buf[i++] = t1 & 0xFF;

// Channel 2 - Temperature
buf[i++] = 2; buf[i++] = 0x67;
let t2 = Math.round(temp2 * 10);
buf[i++] = (t2 >> 8) & 0xFF;
buf[i++] = t2 & 0xFF;

// Channel 3 - Humidity
buf[i++] = 3; buf[i++] = 0x68;
buf[i++] = Math.round(hum1 * 2);

// Channel 4 - Humidity
buf[i++] = 4; buf[i++] = 0x68;
buf[i++] = Math.round(hum2 * 2);

return buf;
}

msg.multicastGroupId = "4820fc7f-0579-46a6-a67f-96d46e2c0cd7";
msg.fPort = 10;
msg.payload = encodeCayenneLPP(25.5, 22.3, 65, 58);
return msg;
`

Input

$3


Type: string
Required: Yes (if not configured in node)
The UUID of the multicast group in ChirpStack.

$3

Type: number
Required: No (default: 10)
LoRaWAN application port (1-223).

$3

Type: Buffer | string | object
Required: Yes
The data to send. Supports:
- Buffer: Raw binary data
- Hex string: "48656C6C6F"
- Base64 string: "SGVsbG8="
- UTF-8 string: "Hello"

Output

$3

`javascript
{
"success": true,
"fCnt": 42,
"multicastGroupId": "4820fc7f-0579-46a6-a67f-96d46e2c0cd7",
"fPort": 10,
"timestamp": "2024-11-05T10:30:00.000Z"
}
`

$3

`javascript
{
"success": false,
"error": "Error message"
}
`

Supported Data Formats

| Format | Example | Detection |
|--------|---------|-----------|
| Buffer | Buffer.from([0x01, 0x02]) | Buffer.isBuffer() |
| Hex | "48656C6C6F" | Regex: ^[0-9A-Fa-f]+$ |
| Base64 | "SGVsbG8=" | Regex: ^[A-Za-z0-9+/=]+$ |
| UTF-8 | "Hello World" | Default fallback |

ChirpStack Configuration

$3

1. In ChirpStack web interface, go to Applications
2. Select your application
3. Click Multicast groups → Create
4. Configure:
- Name: Your group name
- Region: EU868, US915, etc.
- Multicast address: 4-byte address
- Network session key (McNwkSKey)
- Application session key (McAppSKey)
- Frame counter: Start at 0
- Data rate: Compatible with all devices
- Frequency: RX2 frequency for your region

$3

1. Go to your multicast group
2. Click Add device
3. Select devices (must be Class C)

$3

Your LoRa-E5 modules must be in Class C:
`
AT+CLASS=C
`

Troubleshooting

$3


- Ensure multicastGroupId is set in node configuration or msg

$3

- Check ChirpStack server address (default: localhost:8080)
- Verify API token is valid
- Check ChirpStack logs: docker logs -f chirpstack

$3

- Verify devices are in Class C mode
- Check devices are members of the multicast group
- Verify multicast group frequency and data rate
- Check ChirpStack gateway connection

$3

Enable debug mode in node configuration to see:
- Multicast Group ID
- fPort
- Data (hex and base64)

Example Flow

`json
[{"id":"inject1","type":"inject","name":"Test Multicast","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":140,"y":100,"wires":[["function1"]]},{"id":"function1","type":"function","name":"Prepare Data","func":"msg.multicastGroupId = \"4820fc7f-0579-46a6-a67f-96d46e2c0cd7\";\nmsg.fPort = 10;\nmsg.payload = Buffer.from(\"Hello\");\nreturn msg;","outputs":1,"x":310,"y":100,"wires":[["multicast1"]]},{"id":"multicast1","type":"chirpstack-multicast","name":"Send Multicast","server":"server1","multicastGroupId":"","fPort":10,"debug":true,"x":500,"y":100,"wires":[["debug1"]]},{"id":"debug1","type":"debug","name":"Response","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":680,"y":100,"wires":[]}]
`

API Reference

$3

Uses ChirpStack's MulticastGroupService.Enqueue method.

$3

`protobuf
service MulticastGroupService {
rpc Enqueue(EnqueueMulticastGroupQueueItemRequest) returns (EnqueueMulticastGroupQueueItemResponse);
}
``

Contributing

Contributions are welcome! Please:
1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

License

MIT License - see LICENSE file for details

Author

Votre Nom

Links

- GitHub Repository
- npm Package
- ChirpStack Documentation
- Node-RED

Changelog

$3

- Initial release
- Support for ChirpStack v4.x
- Multiple data format support
- Debug mode