Question

我一直在玩 Raspberry Pi 和 Node 以获得乐趣。我想了一个简单的实验，如果我抓住一些用户输入来打开和关闭LED。

const readline = require('readline');
const log = console.log;
const five = require('johnny-five');
const raspi = require('raspi-io');
const board = new five.Board({
  io: new raspi(),
});

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

board.on('ready', function() {
  const led = new five.Led('P1-7');

  const recursiveAsyncReadLine = function () {
    rl.question('Command: ', function (answer) {
      switch(answer) {
        case 'on':
          log('Got it! Your answer was: "', answer, '"');
          led.on();
          break;
        case 'off':
          log('Got it! Your answer was: "', answer, '"');
          led.stop().off();
          break;
        default:
      }
      recursiveAsyncReadLine();
    });
  };
  recursiveAsyncReadLine();
});

它可以工作，但我得到2个奇怪的错误。在下面的控制台输出中，您将看到它提示输入...我输入我的输入，然后它以扭曲的文本字符串重复我的输入（参见实施例1）。然后输出我的验证消息（得到它！你的答案是：“打开”）我遇到了ReferenceError: on is not defined（例2），即使 LED完美亮起。

Command: on
oonn  //Example 1
Got it! Your answer was: " on "
Command:
ReferenceError: on is not defined //Example 2
>> off
ooffff
Got it! Your answer was: " off "
Command:
ReferenceError: off is not defined
>> on
oonn
Got it! Your answer was: " on "
Command:
ReferenceError: on is not defined
>> off
ooffff
Got it! Your answer was: " off "
Command:
ReferenceError: off is not defined
>> on
oonn
Got it! Your answer was: " on "
Command:
ReferenceError: on is not defined
>> off
ooffff
Got it! Your answer was: " off "
Command:
ReferenceError: off is not defined

我认为这不是一个Raspberry Pi / Johnny-five，而只是一个普通的JavaScript或Node问题。

有什么想法吗？

Answer 1

好的回顾我之前的陈述看起来好像是你的问题

led.stop().off();

在Johny-five的例子中，他们表示

led.stop();
led.off();

http://johnny-five.io/examples/led/

祝你好运，快乐的黑客行为： - ）

Answer 2

如果你减少到这个（对我有用）会发生什么？

const readline = require('readline');
const log = console.log;

const rl = readline.createInterface({
     input: process.stdin,
     output: process.stdout
   });

   const recursiveAsyncReadLine = function () {
          rl.question('Command: ', function (answer) {
             switch(answer) {
                case 'on':
                   log('Got it! Your answer was: "', answer, '"');
                break;
                   case 'off':
                   log('Got it! Your answer was: "', answer, '"');
                   break;
                default:
              }
              recursiveAsyncReadLine();
       });
 };

 recursiveAsyncReadLine();

如果有效，那至少告诉我们它与raspi-io或johnny-five的交互有关。此处运行的位置，此代码是否在pi上执行，如果是，您是直接在pi上输入文本还是远程输入。如果远程输入，您输入文本的机器的平台是什么？

节点中的ReferenceError使用用户输入的readline

2 个答案: