06 Pico W網路應用

(2022/12/11)

• Raspberry Pi Pico W 式款低成本且高靈活應用的 RP2040 開發平台，此外還有2.4GHz 無線接口和以下主要功能：

  • 內建 2MB 外部閃存的 RP2040 微控制器晶片

  • 2.4GHz 無線 (802.11n) 介開發板載

  • 用於電源、數據與對閃存重新編程的微型 USB 接口

  • 帶有 0.1 英寸通孔針的 40 針 21mm×51mm 'DIP' 型 1mm 厚的邊緣齒型 PCB

  • 外露 26 個多功能 3.3V 通用 I/O (GPIO)

  • 有 23 個僅適用於數字與另外 3 個支援 ADC 的 GPIO

  • 可作為模組進行表面貼裝

• Raspberry Pi Pico W 的完整詳細訊息可在 Raspberry Pi Pico W 數據表 中找到

• 發出 HTTP 請求

  • 您可以使用原始套接字對 HTTP 請求採用低級方法

    • 搭配 sockets 的 HTTP

      • # Connect to network

      • import network

      • 
        

      • wlan = network.WLAN(network.STA_IF)

      • wlan.active(True)

      • wlan.connect('Wireless Network', 'The Password')

      • 
        

      • # Should be connected and have an IP address

      • wlan.status() # 3 == success

      • wlan.ifconfig()

      • 
        

      • # Get IP address for google

      • import socket

      • ai = socket.getaddrinfo("google.com", 80)

      • addr = ai[0][-1]

      • 
        

      • # Create a socket and make a HTTP request

      • s = socket.socket()

      • s.connect(addr)

      • s.send(b"GET / HTTP/1.0\r\n\r\n")

      • 
        

      • # Print the response

      • print(s.recv(512))

• • 也可以使用 urequests 庫採用高級方法。

    • 搭配 urequests 的 HTTP

      • # Connect to network

      • import network

      • wlan = network.WLAN(network.STA_IF)

      • wlan.active(True)

      • wlan.connect('Wireless Network', 'The Password')

      • 
        

      • # Make GET request

      • import urequests

      • r = urequests.get("http://www.google.com")

      • print(r.content)

      • r.close()

• 利用網頁來控制內建LED燈的亮滅

  • 掃描WiFi

    • import network

    • wlan = network.WLAN(network.STA_IF)

    • wlan.active(True)

    • print(wlan.scan())

  • 建一個secrets.py來存WIFI的SSID及密碼

    • secrets = {

    • 'ssid': 'Replace-this-with-your-Wi-Fi-Name',

    • 'pw': 'Replace-this-with-your-Wi-Fi-Password'

    • }

  • 主要程式(main,py)

    • import rp2

    • import network

    • import ubinascii

    • import machine

    • import urequests as requests

    • import time

    • from secrets import secrets

    • import socket

    • 
      

    • # Set country to avoid possible errors

    • rp2.country('DE')

    • 
      

    • wlan = network.WLAN(network.STA_IF)

    • wlan.active(True)

    • # If you need to disable powersaving mode

    • # wlan.config(pm = 0xa11140)

    • 
      

    • # See the MAC address in the wireless chip OTP

    • mac = ubinascii.hexlify(network.WLAN().config('mac'),':').decode()

    • print('mac = ' + mac)

    • 
      

    • # Other things to query

    • # print(wlan.config('channel'))

    • # print(wlan.config('essid'))

    • # print(wlan.config('txpower'))

    • 
      

    • # Load login data from different file for safety reasons

    • ssid = secrets['ssid']

    • pw = secrets['pw']

    • 
      

    • wlan.connect(ssid, pw)

    • 
      

    • # Wait for connection with 10 second timeout

    • timeout = 10

    • while timeout > 0:

    • if wlan.status() < 0 or wlan.status() >= 3:

    • break

    • timeout -= 1

    • print('Waiting for connection...')

    • time.sleep(1)

    • 
      

    • # Define blinking function for onboard LED to indicate error codes

    • def blink_onboard_led(num_blinks):

    • led = machine.Pin('LED', machine.Pin.OUT)

    • for i in range(num_blinks):

    • led.on()

    • time.sleep(.2)

    • led.off()

    • time.sleep(.2)

    • # Handle connection error

    • # Error meanings

    • # 0 Link Down

    • # 1 Link Join

    • # 2 Link NoIp

    • # 3 Link Up

    • # -1 Link Fail

    • # -2 Link NoNet

    • # -3 Link BadAuth

    • 
      

    • wlan_status = wlan.status()

    • blink_onboard_led(wlan_status)

    • 
      

    • if wlan_status != 3:

    • raise RuntimeError('Wi-Fi connection failed')

    • else:

    • print('Connected')

    • status = wlan.ifconfig()

    • print('ip = ' + status[0])

    • # Function to load in html page

    • def get_html(html_name):

    • with open(html_name, 'r') as file:

    • html = file.read()

    • return html

    • 
      

    • # HTTP server with socket

    • addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1]

    • 
      

    • s = socket.socket()

    • s.bind(addr)

    • s.listen(1)

    • 
      

    • print('Listening on', addr)

    • led = machine.Pin('LED', machine.Pin.OUT)

    • 
      

    • # Listen for connections

    • while True:

    • try:

    • cl, addr = s.accept()

    • print('Client connected from', addr)

    • r = cl.recv(1024)

    • # print(r)

    • r = str(r)

    • led_on = r.find('?led=on')

    • led_off = r.find('?led=off')

    • print('led_on = ', led_on)

    • print('led_off = ', led_off)

    • if led_on > -1:

    • print('LED ON')

    • led.value(1)

    • if led_off > -1:

    • print('LED OFF')

    • led.value(0)

    • response = get_html('index.html')

    • cl.send('HTTP/1.0 200 OK\r\nContent-type: text/html\r\n\r\n')

    • cl.send(response)

    • cl.close()

    • except OSError as e:

    • cl.close()

    • print('Connection closed')

    • 
      

    • # Make GET request

    • #request = requests.get('http://www.google.com')

    • #print(request.content)

    • #request.close()
      

  • index.html

    • <!DOCTYPE html>

    • <html>

    • <head>

    • <title>Pico W</title>

    • </head>

    • <body>

    • <h1>Pico W</h1>

    • <p>Control the onboard LED</p>

    • <a href=\"?led=on\"><button>ON</button></a>&nbsp;

    • <a href=\"?led=off\"><button>OFF</button></a>

    • </body>

    • </html>