@mschaeffler/node-red-lora

Five nodes to send and receive LoRaWan messages via a gateway via the Semtech UDP protocol.

Install

$ npm install @mschaeffler/node-red-lora

Usage

By combining this five nodes, you can receive and send LoRaWan messages via a compatible gateway.

lora server

This node is a UDP server to communicate with LoRa gateways via the SEMTECH protocol.

Input

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | encoded txpk object generated py lora encoder.|

Outputs

tx

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | received message to be processed by lora decoder.| |mac | string | mac of the gateway. |

stat

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | statistical data from gateway. | |mac | string | mac of the gateway. |

Parameters

|config| type | description | |:-----|:-------|:----------------------------------| |UDP Port | number | port at which the server receives messages from the gateway.|

lora decoder

This node decodes a LoraWan message received by lora server. It also generates messages to be sent to the end node in case of

• confirmed messages: the corresponding acknowledgment
• a message for this node from the send queue (s. lora send).

By this the downlink messages can be timed to be sent in the RX1 receive window of the LoRa end node.

Input

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | lora message received by lora server.|

Outputs

decoded payload

|msg. | type | description | |:-------|:-------|:----------------------------------| |topic | string | name of the end node from lora keys.| |payload | object | decoded message to be further processed by lora check FC.| |timeout | number | timeout, if present in lora keys for this node.|

{
    "rxpk": {                    // data from lora server
        "tmst": 501680883,
        "chan": 0,
        "rfch": 1,
        "freq": 868.1,
        "stat": 1,
        "modu": "LORA",
        "datr": "SF7BW125",
        "codr": "4/5",
        "lsnr": 10.3,
        "rssi": -67,
        "size": 23,
        "data": "...",
        "time": 1643556838991
    },
    "device_address": "123456ab",
    "frame_count": 4592,
    "port": 10,
    "mtype": "Confirmed Data Up",
    "confirmed": true,           // confirmed uplink?
    "type": "FooType",           // type of the lora node from lorawan-keys
    "name": "FooBar",            // name of the lora node from lorawan-keys
    "data": [ 0, 0 ]             // payload of the lora message
}

unknown sender

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | messages from unkown end nodes. |

send message for encoder

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object |message from send queue to be encoded by lora encoder.|

Parameters

|config | type | description | |:--------|:-------------|:--------------------------------| |LoRa Keys|lorawan-keys| configuration node to define the end nodes.| |TX-delay | number | delay in µs for a downlink message (RECEIVE_DELAY1 in LoRa); possibly needs some tweaking.|

lora encoder

This node encodes a LoraWan message.

A local filesystem context store called storeInFile is needed to store the internal data.

Input

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | lora message to be sent; normally from lora decoder, send message for encoder.| |framecounter|number|set frame counter default value from versions <2.0.0; this default value wil be active until Node-RED will be restarted.| |framecounter|object|set frame counters with value from persistent memory.|

Outputs

encoded payload

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | object | encoded message for lora sender.|

frame counters for persistence

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | number | frame counters for the different lora nodes for persistent storage.|

Parameters

|config | type | description | |:--------|:-------------|:--------------------------------| |LoRa Keys|lorawan-keys| configuration node to define the end nodes.| |TX-Power | number | transmit power for the gateway. |

lora check FC

This node checks the frame counter (FC) of a LoraWan message.

It recognizes this situations:

• first message received: ok
• FC 0: ok, startup of end node
• FC increased by one: ok
• FC rollover: ok
• FC increased by more then one: ok + error message missing frame
• FC the same as last valid one: duplicate message
• anything else: error merssage, LoRa message is discared

Input

|msg. | type | description | |:-------|:-------|:----------------------------------| |topic | string | name of the end node from lora keys.| |payload | object | lora message decoded by lora decoder.|

Outputs

checked lora message

|msg. | type | description | |:-------|:-------|:----------------------------------| |topic | string | name of the end node from lora keys.| |payload | object | checked ok message ready for node specific payload decoder.|

duplicate message

|msg. | type | description | |:-------|:-------|:----------------------------------| |topic | string | name of the end node from lora keys.| |payload | object | message in case of a reuse of the last valid farme counter value.|

error message

|msg. | type | description | |:-------|:-------|:----------------------------------| |topic | string | subject of the error message. | |payload | string | error message for logging. | |lora | object | lora msg that caused the error message.|

counters

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload.ok|number| Number of ok messages. | |payload.nok|number| Number of error messages. | |payload.dup|number| Number of duplicate messages. | |payload.mis|number| Number of missing messages. |

lora send

This node puts a LoraWan message into the send queue. The send queue is stored in the flow context sendqueue.

Input

|msg. | type | description | |:-------|:-------|:----------------------------------| |payload | byte array | lora payload to be sent; as an array of bytes or as a Buffer.| |topic | string | name of the LoRa end node as in LoRa Keys.|

Parameters

|config | type | description | |:--------|:-------------|:--------------------------------| |LoRa Keys|lorawan-keys| configuration node to define the end nodes.|

lora keys

This configuration node stores data about the LoRa end nodes.

Parameters

|config | type | description | |:--------|:-------|:--------------------------------| |LoRa-Keys| object | config data about the end nodes.|

{
    <device address in lowercase hex>: {
        "nsw": "<LoRa NwkSKey>",
        "asw": "<LoRa AppSKey>",
        "type": "<Type of the node for further processing>",
        "name": "<Name of the node>",
        "timeout": <Timeout value for further processing, optional>;
    },
    "123456ab": {
        "nsw": "0123456789abcdef0123456789abcdef",
        "asw": "0123456789abcdef0123456789abcdef",
        "type": "FooType",
        "name": "FooBar",
        "timeout": 3600
    },
    ...
}

Example Flow

example flow

Author

Mathias Schäffler

License

LGPL-2.1