Raspberry Node-js GPIO控制

Question

我想打开GPIO4上的LED和按钮。但什么都没发生。日志什么也不会显示。我想我没能打开这个函数或者写这个函数。

var http = require('http');
var Gpio = require('onoff').Gpio;

var LED = new Gpio(4, 'out');


var http = require('http');
http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.write('<button onclick="LEDon()">ON</button>');
    res.write('<button onclick="LEDoff()">OFF</button>');
    function LEDon(){
        LED.writeSync(1);
        console.log('1');
    }
    
    function LEDoff(){
        LED.writeSync(0);
        console.log('2');
    }
  res.end();
}).listen(8080);

Answer 1

你好，欢迎来到这里，

试试这个：

var http = require('http');
var HttpDispatcher = require('httpdispatcher');
var Gpio = require('onoff').Gpio;

var dispatcher = new HttpDispatcher();

var LED = new Gpio(4, 'out');

function handleRequest(request, response){
    try {
        // log the request on console
        console.log(request.url);
        // Dispatch
        dispatcher.dispatch(request, response);
    } catch(err) {
        console.log(err);
    }
}  

dispatcher.onGet('/', function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.write(`
        <form action="/on" method="post">
            <input type="submit" value="On" />
        </form>
    `);


    res.write(`
        <form action="/off" method="post">
            <input type="submit" value="Off" />
        </form>
    `);
});

dispatcher.onPost('/on', function(req, res) {
    LED.writeSync(1);
    console.log('1');
});

dispatcher.onPost('/off', function(req, res) {
    LED.writeSync(0);
    console.log('2');
});

http.createServer(handleRequest).listen(8080);

还需要通过运行httpdispatcher来安装npm i httpdispatcher --save包。

您的代码不能工作的原因是您试图通过浏览器调用节点中的函数，这是不可能的，因此这里我们通过一些表单进行调用，并将调用发送到HTTP服务器，然后触发您的GPIO函数。