@ssv-embedded/ssb-decoder v1.3.0

@ssv-embedded/ssb-decoder

This module decodes the sensor payload.

API

Create instance

• Use default decoder

  const {createDecoder} = require('@ssv-embedded/ssb-decoder');
  const decoder = createDecoder();

  or

  const {createDecoder, defaultDecodeItem} = require('@ssv-embedded/ssb-decoder');
  const decoder = createDecoder({decodeItem: defaultDecodeItem});

• Use own decoder, example:

  const {createDecoder, defaultDecodeItem} = require('@ssv-embedded/ssb-decoder');
  function myDecoder (type, data) {
    // decode my stuff
    if (type === 0x80 && data.length === 4)
      return {'mag-x': data.readFloatLE()};
    if (type === 0x81 && data.length === 4)
      return {'mag-y': data.readFloatLE()};
    if (type === 0x82 && data.length === 4)
      return {'mag-z': data.readFloatLE()};
  
    // decode default staff
    return defaultDecodeItem(type, data);
  }
  const decoder = createDecoder({decodeItem: myDecoder});

Parameter of createDecoder() is optional and can provide a object with initial settings:

• decodeItem: Item decoder callback function with two parameters, required.
  • Input parameter:
    • type: item type to be decoded as Number
    • data: item data to be decoded as Buffer
  • Output should be an Object with one key and value, e.g. {'temp':22.3}

Check payload

const decoded = decoder.decode(payload);

payload: SSV/SSB payload from type Buffer

Return: Object with decoded items as raw data and user decoded data from decodeItem callback. Example output:

{
  raw: {
    '80': <Buffer 66 66 66 be>,
    '81': <Buffer 47 c1 bd>,
    '82': <Buffer 66 66 66 be>
  },
  data: {
    'mag-x': -0.22499999403953552,
    'mag-z': -0.22499999403953552,
  }
}