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android - 如何让我的 android 应用程序与树莓派 3 上的 Flask 服务器交互？

问题描述

我正在尝试遵循 MattRichardson 关于“使用 Flask 服务 Raspberry Pi”的教程（http://mattrichardson.com/Raspberry-Pi-Flask/）。这是我从本网站提到的教程中获得的代码：

import RPi.GPIO as GPIO
from flask import Flask, render_template, request
app = Flask(__name__)

GPIO.setmode(GPIO.BCM)

# Create a dictionary called pins to store the pin number, name, and pin state:
pins = {
   24 : {'name' : 'coffee maker', 'state' : GPIO.LOW},
   25 : {'name' : 'lamp', 'state' : GPIO.LOW}
   }

# Set each pin as an output and make it low:
for pin in pins:
   GPIO.setup(pin, GPIO.OUT)
   GPIO.output(pin, GPIO.LOW)

@app.route("/")
def main():
   # For each pin, read the pin state and store it in the pins dictionary:
   for pin in pins:
      pins[pin]['state'] = GPIO.input(pin)
   # Put the pin dictionary into the template data dictionary:
   templateData = {
      'pins' : pins
      }
   # Pass the template data into the template main.html and return it to the user
   return render_template('main.html', **templateData)

# The function below is executed when someone requests a URL with the pin number and action in it:
@app.route("/<changePin>/<action>")
def action(changePin, action):
   # Convert the pin from the URL into an integer:
   changePin = int(changePin)
   # Get the device name for the pin being changed:
   deviceName = pins[changePin]['name']
   # If the action part of the URL is "on," execute the code indented below:
   if action == "on":
      # Set the pin high:
      GPIO.output(changePin, GPIO.HIGH)
      # Save the status message to be passed into the template:
      message = "Turned " + deviceName + " on."
   if action == "off":
      GPIO.output(changePin, GPIO.LOW)
      message = "Turned " + deviceName + " off."
   if action == "toggle":
      # Read the pin and set it to whatever it isn't (that is, toggle it):
      GPIO.output(changePin, not GPIO.input(changePin))
      message = "Toggled " + deviceName + "."

   # For each pin, read the pin state and store it in the pins dictionary:
   for pin in pins:
      pins[pin]['state'] = GPIO.input(pin)

   # Along with the pin dictionary, put the message into the template data dictionary:
   templateData = {
      'message' : message,
      'pins' : pins
   }

   return render_template('main.html', **templateData)

if __name__ == "__main__":
   app.run(host='0.0.0.0', port=80, debug=True)

对于 main.htm 文件：

<!DOCTYPE html>
<head>
   <title>Current Status</title>
</head>

<body>
   <h1>Device Listing and Status</h1>

   {% for pin in pins %}
   <p>The {{ pins[pin].name }}
   {% if pins[pin].state == true %}
      is currently on (<a href="/{{pin}}/off">turn off</a>)
   {% else %}
      is currently off (<a href="/{{pin}}/on">turn on</a>)
   {% endif %}
   </p>
   {% endfor %}

   {% if message %}
   <h2>{{ message }}</h2>
   {% endif %}

</body>
</html>

上面代码的作用是，它允许用户访问 pi 的 Web 服务器并控制 GPIO 引脚，即打开或关闭它们。

目前，我有一个树莓派提供上述 html 文件供我的网络浏览器访问。然而，我想使用一个简单的安卓应用程序来实现同样的事情，即一个简单的切换按钮，它以某种方式打开或关闭引脚。

这是我的安卓应用程序代码。所有这个应用程序在屏幕中央都有一个简单的按钮，只是为了让我控制引脚。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Switch
        android:id="@+id/switch1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:text="Switch"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

和java代码：

package com.example.testapp;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

谁能帮帮我？

标签： androidpythonflaskraspberry-piraspberry-pi3

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