라즈베리파이 파이썬(python) 플라스크(flask) 사용 LED 켜기/끄기

Posted on: 2019년 10월 12일 2019년 10월 12일
Categories: 강의자료, 라즈베리파이, 파이썬

flask 설치 : 라즈베리파이에 기본으로 설치되어 있음
1. 파이썬 2.x
  1. sudo apt-get install python-pip
  2. sudo pip install flask
2. 파이썬 3.x
  1. sudo apt-get install python3-pip
  2. sudo pip3 install flask

간단한 웹서버 구축 : web_server.py

from flask import Flask

app=Flask(__name__)

@app.route('/')
def index():
    return 'This is main page.'

@app.route('/sub')
def sub():
    return 'This is sub page.'

@app.route('/led/<state>')
def led(state):
    if state == 'on' or state == 'off':
        str = 'Led is now %s.' % state
    else:
        str = 'Invalid Pages'
    return str

if __name__ == '__main__':
    print('Webserver start.')
    app.run(debug=True, port=1234, host='0.0.0.0')

from flask import Flask

app=Flask(__name__)

@app.route('/')

def index():

return 'This is main page.'

@app.route('/sub')

def sub():

return 'This is sub page.'

@app.route('/led/<state>')

def led(state):

if state == 'on' or state == 'off':

str = 'Led is now %s.' % state

else:

str = 'Invalid Pages'

return str

if __name__ == '__main__':

print('Webserver start.')

app.run(debug=True, port=1234, host='0.0.0.0')

route() 메서드가 Flask에 정의되어 있어 그것을 사용
debug=True : 디버깅 결과를 출력
port=1234 : 1234 Port를 사용(기본은 5000번 포트 사용)
host=0.0.0.0 : public하게 하여 모두 접속 가능

실행 : python3 web_server.py

pi@raspberrypi:~/webapp $ python3 web_server.py
Webserver start.
 * Serving Flask app "web_server" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://0.0.0.0:1234/ (Press CTRL+C to quit)
 * Restarting with stat
Webserver start.
 * Debugger is active!
 * Debugger PIN: 238-007-790
192.168.0.10 - - [12/Oct/2019 10:39:12] "GET /led/off HTTP/1.1" 200 -
192.168.0.10 - - [12/Oct/2019 10:39:13] "GET /favicon.ico HTTP/1.1" 404 -
192.168.0.10 - - [12/Oct/2019 10:39:24] "GET /led/on HTTP/1.1" 200 -
192.168.0.10 - - [12/Oct/2019 10:39:28] "GET /sub HTTP/1.1" 200 -
192.168.0.10 - - [12/Oct/2019 10:39:33] "GET / HTTP/1.1" 200 -
 * Detected change in '/home/pi/webapp/web_server.py', reloading
 * Restarting with stat
Webserver start.
 * Debugger is active!
 * Debugger PIN: 238-007-790

pi@raspberrypi:~/webapp $ python3 web_server.py

Webserver start.

* Serving Flask app "web_server" (lazy loading)

* Environment: production

WARNING: Do not use the development server in a production environment.

Use a production WSGI server instead.

* Debug mode: on

* Running on http://0.0.0.0:1234/ (Press CTRL+C to quit)

* Restarting with stat

Webserver start.

* Debugger is active!

* Debugger PIN: 238-007-790

192.168.0.10 - - [12/Oct/2019 10:39:12] "GET /led/off HTTP/1.1" 200 -

192.168.0.10 - - [12/Oct/2019 10:39:13] "GET /favicon.ico HTTP/1.1" 404 -

192.168.0.10 - - [12/Oct/2019 10:39:24] "GET /led/on HTTP/1.1" 200 -

192.168.0.10 - - [12/Oct/2019 10:39:28] "GET /sub HTTP/1.1" 200 -

192.168.0.10 - - [12/Oct/2019 10:39:33] "GET / HTTP/1.1" 200 -

* Detected change in '/home/pi/webapp/web_server.py', reloading

* Restarting with stat

Webserver start.

* Debugger is active!

* Debugger PIN: 238-007-790

웹브라우저에서 접속
1. http://192.168.0.14:1234/
  1. 출력 : This is main page.
2. http://192.168.0.14:1234/sub
  1. 출력 : This is sub page.
3. http://192.168.0.14:1234/led/on
  1. 출력 : Led is now on
4. http://192.168.0.14:1234/led/off
  1. 출력 : Led is now off

flask를 이용하여 LED를 켜고 끄기 구현

서버 실행 : python3 web_led.py
클라이언트 접속 결과

flask 웹서버 구성 : web_led.py

import RPi.GPIO as gpio
from flask import Flask, render_template
import warnings

app=Flask(__name__)

warnings.filterwarnings('ignore')

LED = 4

def led_turn(st):
    if st == 'on':
        gpio.output(LED, gpio.HIGH)
    else:
        gpio.output(LED, gpio.LOW)

@app.route('/')
def index():
    return render_template('index.html', state='off')

@app.route('/led/<st>')
def led(st):
    led_turn(st)
    return render_template('index.html', state=st)


if __name__ == '__main__':
    gpio.setmode(gpio.BCM)
    gpio.setup(LED, gpio.OUT)
    led_turn('off')

    print('Webserver start.')
    app.run(debug=True, port=1234, host='0.0.0.0')
    gpio.cleanup()

import RPi.GPIO as gpio

from flask import Flask, render_template

import warnings

app=Flask(__name__)

warnings.filterwarnings('ignore')

LED = 4

def led_turn(st):

if st == 'on':

gpio.output(LED, gpio.HIGH)

else:

gpio.output(LED, gpio.LOW)

@app.route('/')

def index():

return render_template('index.html', state='off')

@app.route('/led/<st>')

def led(st):

led_turn(st)

return render_template('index.html', state=st)

if __name__ == '__main__':

gpio.setmode(gpio.BCM)

gpio.setup(LED, gpio.OUT)

led_turn('off')

print('Webserver start.')

app.run(debug=True, port=1234, host='0.0.0.0')

gpio.cleanup()

홈페이지 구성:/templates/index.html

<!doctype html>

<html>
<head>
	<title> LED Turn On/Off </title>
	<link type="text/css" rel="stylesheet" href="/static/style.css"/>
</head>

<body>
	<p></p>
	<input type="button" value="켜기" style="WIDTH:200pt; HEIGHT:80pt; font-size:50pt" onclick="location.href='/led/on'";>
	&nbsp;&nbsp;&nbsp;&nbsp;
	<input type="button" value="끄기" style="WIDTH:200pt; HEIGHT:80pt; font-size:50pt" onclick="location.href='/led/off'";>
	<br/>
	<p> LED is now <span id="state">{{state}}</span> state.</p>
</body>
</html>

<!doctype html>

<html>

<head>

</head>

<body>

<p></p>

<br/>

<p> LED is now <span id="state">{{state}}</span> state.</p>

</body>

</html>

홈페이지 스타일 지정 : /static/style.css

body{ background-color: black; text-align: center; } p{ font-size: 50px; color: yellow; } #state{ font-size: 80px; color: red; }

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body{
background-color: black;
text-align: center;
}

p{
font-size: 50px;
color: yellow;
}

#state{
font-size: 80px;
color: red;
}

whan0623

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