樹莓派上的40個GPIO是最好玩的東西
它們可以被C,/C++, Python, Java等語言直接控制
現在就來看看怎麼用Node.js做到同樣的事情
在試驗之前, 請先安裝好Node.js, 具體可以移步到: <樹莓派.安裝系統+Node.js+MongoDB系列環境>
1.準備試驗檔案夾
mkdir /home/pi/Documents/test-gpio-demo/
2.建立檔案package.json
{
"name": "test-gpio-demo",
"version": "0.0.1",
"dependencies":{
"rpio2":"0.4.1"
}
}
3.建立主檔案blank.js
//blink.js
const Gpio = require('/home/pi/Documents/test-gpio/node_modules/rpio2/lib/index.js').Gpio;
var led = new Gpio(36); //建立 P36 引腳
led.open(Gpio.OUTPUT, Gpio.LOW); //設定為 OUTPUT、預設低電平
for(var i = 0; i < 20; i++){
led.toggle(); //切換 led 的電平狀态
led.sleep(300); //等待 500ms
}
led.close();
4.硬體電路連接配接
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiInBnaukzM3YTN0YTM50SNwADOxMDN4ETMwgDM3EDMy0SM0QTO5ETMvwFOwcTMwIzLcFDN0kTOxEzLcd2bsJ2Lc12bj5ycn9Gbi52YucTMwIzcldWYtl2Lc9CX6MHc0RHaiojIsJye.jpg)
第36腳(GPIO16) 經過一個電阻(220歐或1K都可以),再接到LED的正級
LED負級接到第34腳(GND)
5.試運作
node /home/pi/Documents/test-gpio-demo/blank.js
閃燈效果:
亮燈
滅燈:
試驗成功!
===============================分隔線=========================
rpio2正常用法:
Synchronously
const Gpio = require('./lib/index.js').Gpio;
const gpio = new Gpio(40);
gpio.open(Gpio.OUTPUT);
for(var i = 0; i < 10; i++){
gpio.toggle();
gpio.sleep(500);
}
gpio.close();
Asynchronously
const Gpio = require('../lib/index.js').Gpio;
const gpio = new Gpio(40);
gpio.open(Gpio.OUTPUT);
void function loop(){
Promise.resolve(gpio.toggle())
.then(gpio.sleep.bind(null, 500, true))
.then(loop)
}();
process.on("SIGINT", function(){
gpio.close();
console.log('shutdown!');
process.exit(0);
});
Toggle with button
const Gpio = require('../lib/index.js').Gpio;
const button = new Gpio(32);
const output = new Gpio(40);
button.open(Gpio.INPUT);
output.open(Gpio.OUTPUT, Gpio.LOW);
//button down
button.on('rising', function(){
output.toggle();
});
process.on("SIGINT", function(){
button.close();
output.close();
console.log('shutdown!');
process.exit(0);
});