Payload functions

2

The TTN code uses:

…which says:

Otto targets ES5. ES6 features (eg: Typed Arrays) are not supported.

And some other TTN code documents:

// Decoder is a JavaScript function that accepts the payload as byte array and
// returns an object containing the decoded values
...
// Converter is a JavaScript function that accepts the data as decoded by
// Decoder and returns an object containing the converted values
...

More browsing shows that the first parameter is a Go []byte, which will become a JavaScript array of numbers. (JavaScript does not have bytes.) That is confirmed by a Decoder that prints it, just to investigate a bit:

function Decoder(bytes, port) {
  return { 
     bytes: {
       toString: Object.prototype.toString.call(bytes),
       typeof: typeof bytes
     },
     item: {
       toString: Object.prototype.toString.call(bytes[0]),
       typeof: typeof bytes[0]
     }
  };
}

…which yields:

{
  "bytes": {
    "toString": "[object Array]",
    "typeof": "object"
  },
  "item": {
    "toString": "[object Number]",
    "typeof": "number"
  }
}

So, JavaScript (ECMAScript 5) with an array of numbers. The best resource is Mozilla Developer Network, I feel, and “mdn” is a great keyword for search engines: mdn array. Also, you can use auto-completion in the developer console of your browser. Just start with something like:

var bytes = [0x31, 0x31, 0x31, 0x20, 0x30, 0x31, 0x34, 0x00];

…after which typing bytes. will show you the supported functions and all.

I’m quite sure it’s not, but just repeating that question here :slight_smile:

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