01. About neqto.js

neqto.js is a JavaScript environment that runs on the NEQTO Engine.
neqto.js has the following features.

About standard objects

neqto.js is compatible with ECMAScript 5.1 Edition.
Additionally, some key features of ArrayBuffer, TypedArray, and Template Literals defined in ECMAScript 2015 (ES6) Edition are available.

The system time uses GMT format.

About extension objects

Extension objects provide an interface to easily control NEQTO device specific functions, external devices, and external sensors.
For the details of an extension, refer to the description page of each extension.

Limitations

• The maximum size of script code is 127K bytes.

• The amount of available memory (RAM) on the script code is finite.
  If the memory is exhausted, the device will enter safe mode.
  Detailed memory information can be obtained using the heap() method.

• Only one callback can be executed at a time.
  It is not possible to wait for another callback in a callback process.

• It is recommended to execute callbacks quickly and to not perform long blocks during callback executions.

• If the function call hierarchy (nested functions) becomes too deep, it may cause an unexpected system reset due to stack overflow. Be especially careful when using recursive functions. It is recommended that the function call hierarchy be within a few steps and that the implementation always behaves within expectations.

• The try-catch function is supported in FW version 01.01.00 and later.

Explanatory notes

Legend for extension description pages.

• { } Braces indicate an object.

• [ ] Square brackets around an argument inside a method description indicate the argument is optional. If the option is the beginning of the argument, omit the delimiters ','.

  foo.func([opt1][,opt2])
  - foo.func();
  - foo.func(opt1);
  - foo.func(opt2); //Omit delimiter
  - foo.func(opt1,opt2);
  

Errata

It has been confirmed that depending on how the JavaScript code is written, the desired behavior may not be achieved.
If any of the following cases are applicable, please apply the appropriate workaround.

Errata 1

Affected Version: 02.01.00 or earlier

If the conditional expression of a while statement uses < and is specified with a variable that is updated externally, the while loop will completely occupy the processing, and all other processes executed outside of the while loop will not function.

Example of event occurrence: cnt is a variable that is updated externally.

var cnt = 0;

var tm = setInterval(function() {
    print('Interval:' + cnt);
    cnt++;
}, 1000);

while(cnt < 10) {
}

clearInterval(tm);

Workaround 1: Using an if-break within while.

var cnt = 0;

var tm = setInterval(function() {
    print('Interval:' + cnt);
    cnt++;
}, 1000);

while(1) {
    if(cnt >= 10) break;
}

clearInterval(tm);

Workaround 2: Using an inequality sign other than < in the conditional expression of the while statement.

var cnt = 0;

var tm = setInterval(function() {
    print('Interval:' + cnt);
    cnt++;
}, 1000);

while(cnt <= 9) {
}

clearInterval(tm);

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Updated: 2025-01-23