Node-Red component to read NMEA 0183 sentences
npm install @coremarine/nmea-parser-nodered!npm (scoped)
!npm
Node-Red component to read NMEA 0183 sentences. It is a wrapper of @coremarine/nmea-parser (check it docs).
NMEA component uses 5 properties to work:
- payload is the main property with NMEA content.
- protocols, sentence, memory and fake are optionals.
| Input property | Description |
| :--------------------- | :------------------------------------------------------------------------------------- |
| payload (string) | NMEA ASCII content (important, it is an ASCII string, not other encoding). |
| memory (object) | Object to check or enabled / disabled parser memory state (look details below). |
| protocols (object) | Object to get or set the protocols supported and their sentences (look details below). |
| sentence (string) | Sentence ID to get if it is supported and its info (look details below). |
| fake (string) | Sentence ID to get a full fake NMEA-like sentence if it is supported. |
Each input proerty would be responded in the same output property
| Output property | Description |
| :--------------------- | :----------------------------------------------------------------------------------------------------------------------------- |
| payload (array) | It gives you the same parsing output that the CoreMarine NMEA Parser (an array of object with the info of each NMEA sentence). |
| memory (object) | Response to the memory input (look details below). |
| protocols (object) | Response to the protocols input (look details below). |
| sentence (string) | Response to the sentence input (look details below). |
| fake (string) | Response to the fake input (look details below). |
NMEA parser translate NMEA ASCII string data into a JavaScript objects (one for each
NMEA 0183 sentence). Each time it receives data from payload input, it gives the parsed sentences to payload output.
It just a wrapper of the npm library @coremarine/nmea-parser (take a look on it).
To interact with the memory | protocols | sentence API is through the memory | protocols | sentence property:
- If you request something in msg.memory | msg.protocols | msg.sentence input
- The response will be in msg.memory | msg.protocols | msg.sentence output
It is enabled by default:
- memory enabled: Every time you inject data, it's attached to the internal data.
- memory disabled: Every time you inject data, it clears internal data and add new one.
Internally it has a buffer with a max number of characters
| Input | Output |
| :------------------------------------------------------: | :-----------------------------------------------------------: |
| memory: { command: "set", payload: boolean } | memory: { memory: boolean, characters: number } |
| memory: { command: "get" } | memory: { memory: boolean, characters: number } |
The parser can be feeded or expanded to understand more nmea sentences, standard or propietary.
To do that it should be passed an object with the property command equal to "set" and one this three properties:
1. file: It's the string file path to the protocols YAML file.
2. content: It's the string content of the protocols YAML file.
3. protocols: It's the JS object after parsing the protocols YAML file.
If you send more of them, parser only will read one (file upper other, content upper protocols)
If you just want to know what are the known or supported sentences, you just need the command get.
| Input | Output |
| :----------------------------------------------------------: | :--------------------: |
| protocols: { command: "set", file: string } | protocols: array |
| protocols: { command: "set", content: string } | protocols: array |
| protocols: { command: "set", protocols: object } | protocols: array |
| protocols: { command: "get" } | protocols: array |
If you want to know if a sentence is known / supported, you need to send the sentence id.
Response will be an object with the whole info or null if it's unknown / not supported yet.
| Input | Output |
| :--------------------: | :------------------------------: |
| sentence: string | sentence: object \| null |
If you want to get a NMEA-like sentence, maybe just to do some tests, you need to send the sentence id.
Response will be a string with the whole ASCII sentence or null if it's unknown / not supported yet.
This fake sentence is correct in terms of NMEA requirements but each field has garbage.
| Input | Output |
| :----------------: | :--------------------------: |
| fake: string | fake: string \| null |