本文的目的是介绍pySerial在Python解释器中可以正常工作，但不能独立运行的详细情况，我们将通过专业的研究、有关数据的分析等多种方式，同时也不会遗漏关于127.0.0.1可以访问/正常工作，但

本文的目的是介绍pySerial在Python解释器中可以正常工作，但不能独立运行的详细情况，我们将通过专业的研究、有关数据的分析等多种方式，同时也不会遗漏关于127.0.0.1可以访问/正常工作，但localhost不可访问/不能正常工作、bash – 在python解释器提示符中添加颜色,不能正确包装、heroku local可以正常运行，但不能在线运行（Ionic和Firebase后端）、OS X Terminal中Python解释器中的制表符完成的知识。

• pySerial在Python解释器中可以正常工作，但不能独立运行
• 127.0.0.1可以访问/正常工作，但localhost不可访问/不能正常工作
• bash – 在python解释器提示符中添加颜色,不能正确包装
• heroku local可以正常运行，但不能在线运行（Ionic和Firebase后端）
• OS X Terminal中Python解释器中的制表符完成

pySerial在Python解释器中可以正常工作，但不能独立运行

早上好！最近，我买了一个Arduino开发板来对房间进行“灯光控制”。这是我编写的固件代码：

int control = 0;int pin = 0;void setup(){  Serial.begin(9600);  for(pin = 0; pin <= 13; pin++) pinMode(pin, OUTPUT);}void loop(){  control = Serial.read();  if (control > 0 && control <= 13) digitalWrite(control, HIGH);  if (control < 256 && control >= (256-13)) digitalWrite((256-control), LOW);}

之后，我使用了Python解释器中的pySerial来控制引脚，一切工作正常。这是一段解释器输出：

Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) [GCC 4.4.3] on linux2Type "help", "copyright", "credits" or "license" for more information.>>> import serial>>> ser = serial.Serial(''/dev/ttyUSB0'', 9600)>>> ser.write(chr(12))>>> # The light turned on here... >>> ser.write(chr(256-12))>>> # The light turned off here...

然后，我决定编写一个简单的Python脚本来执行相同的操作：

#!/usr/bin/env pythonimport serialimport timeser = serial.Serial(''/dev/ttyUSB0'', 9600)ser.write(chr(12))time.sleep(1)ser.write(chr(256-12))

但这根本不起作用！Arduino显示在我启动脚本的过程中收到了一些东西，但是什么也没发生。这是脚本的strace输出：

open("/dev/ttyUSB0", O_RDWR|O_NOCTTY|O_NONBLOCK) = 3ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(3, SNDCTL_TMR_START or TCSETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0open("/dev/ttyUSB0", O_RDWR|O_NOCTTY|O_NONBLOCK) = 4ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(4, SNDCTL_TMR_START or TCSETS, {B9600 -opost -isig -icanon -echo ...}) = 0ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 -opost -isig -icanon -echo ...}) = 0write(4, "\f", 1)                       = 1close(4)                                = 0rt_sigaction(SIGINT, {SIG_DFL, [], SA_RESTORER, 0x7f45cf4c88f0}, {0x4d9820, [], SA_RESTORER, 0x7f45cf4c88f0}, 8) = 0exit_group(0)                           = ?

看起来一切都应该很好，所以我不知道问题可能出在哪里。我将不胜感激，在此先感谢您！

PS当我在PDB下运行该程序时，一切正常。Heisenbug。

更新：我让控制器将接收到的数据发回给我，并且在运行脚本时似乎什么也没接收到，但是当我从解释器发送数据时，接收到了所有内容。固件的代码现在如下所示：

int control = 0;int pin = 0;void setup(){  Serial.begin(9600);  for(pin = 0; pin <= 13; pin++) pinMode(pin, OUTPUT);}void loop(){  if (Serial.available() > 0)  {    control = Serial.read();    if (control <= 13) digitalWrite(control, HIGH);    if (control < 256 && control >= (256-13)) digitalWrite((256-control), LOW);    Serial.println(control);  }}

答案1

我认为这可能是打开串行端口和发送数据之间的竞争状态。我可能会在打开和写入调用之间进行睡眠。

另外，您可能不想打开这个库“ serial”，而是直接打开并直接写入设备，这可能是在做一些有趣的事情（请参阅其他文章中提到的double open）

127.0.0.1可以访问/正常工作，但localhost不可访问/不能正常工作

sys.ps1 = '\033[96m>>> \033[0m'
sys.ps2 = '\033[96m... \033[0m'

sys.ps1 = '\001\033[96m\002>>> \001\033[0m\002'
sys.ps2 = '\001\033[96m\002... \001\033[0m\002'

var express = require("express");
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var morgan = require("morgan");
var bodyParser = require("body-parser");
var cors = require("cors");

app.use(morgan("dev"));
app.use(bodyParser.urlencoded({ extended: "true" }));
app.use(bodyParser.json());
app.use(cors());

app.use(function (req,res,next) {
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  res.header("Access-Control-Allow-Methods","DELETE,PUT");
  res.header(
    "Access-Control-Allow-Headers","Origin,X-Requested-With,Content-Type,Accept"
  );
  next();
});

app.use(express.static("www"));
app.set("port",process.env.PORT || 5000);
app.listen(app.get("port"),function () {
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});

{
  "name": "english","version": "0.0.1","author": "Ionic Framework","homepage": "https://ionicframework.com/","scripts": {
    "ng": "ng","start": "ng serve","build": "ng build","test": "ng test","lint": "ng lint","e2e": "ng e2e"
  },"private": true,"dependencies": {
    "@angular/common": "~10.0.0","@angular/core": "~10.0.0","@angular/fire": "^6.0.2","@angular/forms": "~10.0.0","@angular/platform-browser": "~10.0.0","@angular/platform-browser-dynamic": "~10.0.0","@angular/router": "~10.0.0","@capacitor/core": "2.4.1","@fortawesome/angular-fontawesome": "^0.7.0","@fortawesome/fontawesome-svg-core": "^1.2.30","@fortawesome/free-brands-svg-icons": "^5.14.0","@fortawesome/free-regular-svg-icons": "^5.14.0","@fortawesome/free-solid-svg-icons": "^5.14.0","@ionic-native/core": "^5.0.0","@ionic-native/splash-screen": "^5.0.0","@ionic-native/status-bar": "^5.0.0","@ionic/angular": "^5.0.0","@ionic/app-scripts": "^3.2.4","express": "^4.17.1","firebase": "^7.20.0","ng2-search-filter": "^0.5.1","rxjs": "~6.5.5","tslib": "^2.0.0","typescript": "~3.9.5","zone.js": "~0.10.3"
  },"devDependencies": {
    "@angular-devkit/architect": ">= 0.900 < 0.1100","@angular-devkit/build-angular": "^0.1000.8","@angular/cli": "~10.0.5","@angular/compiler": "~10.0.0","@angular/compiler-cli": "~10.0.0","@angular/language-service": "~10.0.0","@capacitor/cli": "2.4.1","@ionic/angular-toolkit": "^2.3.0","@types/jasmine": "~3.5.0","@types/jasminewd2": "~2.0.3","@types/node": "^12.11.1","codelyzer": "^6.0.0","firebase-tools": "^8.0.0","fuzzy": "^0.1.3","inquirer": "^6.2.2","inquirer-autocomplete-prompt": "^1.0.1","jasmine-core": "~3.5.0","jasmine-spec-reporter": "~5.0.0","karma": "~5.0.0","karma-chrome-launcher": "~3.1.0","karma-coverage-istanbul-reporter": "~3.0.2","karma-jasmine": "~3.3.0","karma-jasmine-html-reporter": "^1.5.0","open": "^7.0.3","protractor": "~7.0.0","ts-node": "~8.3.0","tslint": "~6.1.0"
  },"description": "An Ionic project"
}

import atexitimport os.pathtry:    import readlineexcept ImportError:    passelse:    import rlcompleter    class IrlCompleter(rlcompleter.Completer):        """        This class enables a "tab" insertion if there''s no text for        completion.        The default "tab" is four spaces. You can initialize with ''\t'' as        the tab if you wish to use a genuine tab.        """        def __init__(self, tab=''    ''):            self.tab = tab            rlcompleter.Completer.__init__(self)        def complete(self, text, state):            if text == '''':                readline.insert_text(self.tab)                return None            else:                return rlcompleter.Completer.complete(self,text,state)    #you could change this line to bind another key instead tab.    readline.parse_and_bind(''tab: complete'')    readline.set_completer(IrlCompleter(''\t'').complete)# Restore our command-line history, and save it when Python exits.history_path = os.path.expanduser(''~/.pyhistory'')if os.path.isfile(history_path):    readline.read_history_file(history_path)atexit.register(lambda x=history_path: readline.write_history_file(x))