MicroPython_ESP8266_IoT——第五回 网页配置(局域网连接WiFi)
参考官方手册中,对network库的介绍:network
——network configuration 。
建议在REPL中,通过命令行逐个熟悉提示到的方法,加深理解。
network模块介绍
此模块提供网络连接的驱动,以及路由配置。配置网络后,可以通过usocket
模块获取网络服务。使用起来非常方便,官网教程中也给了例子:
# connect/ show IP config a specific network interface
# see below for examples of specific drivers
import network
import utime
nic = network.Driver(...)
if not nic.isconnected():
nic.connect()
print("Waiting for connection...")
while not nic.isconnected():
utime.sleep(1)
print(nic.ifconfig())
# now use usocket as usual
import usocket as socket
addr = socket.getaddrinfo('micropython.org', 80)[0][-1]
s = socket.socket()
s.connect(addr)
s.send(b'GET / HTTP/1.1\r\nHost: micropython.org\r\n\r\n')
data = s.recv(1000)
s.close()
网络适配接口
这里描述的network
接口针对不同的MicroPython硬件有不同的实例。提供的WiFi网络处理驱动,示例如下:
import network
# enable station interface and connect to WiFi access point
nic = network.WLAN(network.STA_IF)
nic.active(True)
nic.connect('your-ssid', 'your-password')
# now use sockets as usual
其中适用于ESP8266的为class WLAN
,那就以class WLAN
control built-in WiFi interfaces 为例,看看有哪些方法。
创建对象
WLAN 网络接口对象有两种:
network.STA_IF
(station,也叫做client,是连接到上游WiFi接入点);network.AP_IF
(access point,允许其他WiFi clients连接);
下面提到的方法是否可用取决于接口的类型,比如只有STA接口支持WLAN.connect()
来接入access point。如下列举此类中的方法:
- WLAN.active([is_active])
- WLAN.connect(ssid=None, password=None, *, bssid=None)
- WLAN.disconnect()
- WLAN.scan()
- WLAN.status([param])
- WLAN.isconnected()
- WLAN.ifconfig([(ip, subnet, gateway, dns)])
- WLAN.config(‘param’)
- WLAN.config(param=value,…)
这些都比较好理解,根据方法的名称基本就能了解个大概,详细说明可参考官方手册中的WLAN.()介绍。
关键方法WLAN.scan()
此处主要介绍WLAN.scan()
,用于扫描可用的无线网络(类似于手机打开WiFi之后,就开始搜索附近可用的无线网络)。
扫描方法只适用于STA接口
,会返回包含WiFi接入点的信息元组组成的列表,内容如下:
ssid(WiFi ID), bssid(MAC), channel(信道);
RSSI(信号强度), authmode(加密模式), hidden(隐藏);
其中,bssid
为接入点硬件地址,为二进制格式,返回为bytes
对象。可以使用ubinascii.hexlify()
转换为ASCII格式。
authmode
加密方(没有过多了解这些方式的区别,又兴趣可自行探索)有5个值:
- 0 - 不加密;
- 1 - WEP;
- 2 - WPA-PSK;
- 3 - WPA2-PSK;
- 4 - WPA/WPA2-PSK;
hidden
的值也有两种:
- 0 - visible;
- 1 - hidden;
看过了这些方法,可以在REPL
中挨个使用,加深对这些方法的理解(务必学会现在REPL中调试,再向ESP8266中传输文件);
WiFi Manager Works
这一部分内容并非本人原创,这里为Github仓库地址 。使用tayfunuln的WiFiManager,可以使用MicroPython配合ESP32或ESP8266等硬件,进行Wi-Fi连接的管理。
可以理解为手机打开WiFi的开关后,自动搜索周围的WiFi,选中需要连接的WiFi名称,输入对应密码即可连接。此外,还支持记住网络,将WiFi名称自动保存在ESP8266等Flash中,方便复位之后自动连接。
使用场景
方便在更换使用环境的时候,不需要重新在code中修改SSID和PASSWORD,重新烧录程序。
可以想象这么个场景,花时间和心思DIY了一个好玩的,想要分享给女朋友,难道还想要女朋友自己在源码中修改WiFi的账号和密码,再烧录到板子中吗?(如果你不使用Wi-Fi Manager,那么也就只能提前将源码修改好再给女朋友了)
使用ESP8266建立Access Point,之后同通过web配置网络信息,而且可以自动连接已经保存的网络,使用界面如下:
看起来跟手机直连WiFi差不多操作了。
工作原理
WiFi管理模块是这样工作的:
- EPS8266模块第一次重启,会建立Access Point(名称和密码再源码中设定的);
- 连接至上述Access Point后,在浏览器中输入IP地址
192.168.4.1
; - 通过显示出的网页,选择一个SSID,并输入密码,点击
submit
; - ESP8266保存网络的SSID和输入的PASSWORD,转换为Station mode连接入对应的WiFi网络;
- 当新的SSID和PASSWORD设定,ESP8266每次重启,都会被设定为Station mode并尝试连接之前保存的WiFi网络;
- 建立连接后,此模块操作就完成了。否则就回到第一步需要重新配置WiFi网络;
在仓库WiFiManager的主页中README中,可以找到工作原理的框图:
WiFi Manager MicroPython 源码
因为是非官方的库,所以需要将源码保存到ESP8266设备上保存文件名称为wifimgr.py
,方便在main.py
中调用,源码如下:
import network
import socket
import ure
import time
ap_ssid = "WifiManager"
ap_password = "tayfunulu"
ap_authmode = 3 # WPA2
NETWORK_PROFILES = 'wifi.dat'
wlan_ap = network.WLAN(network.AP_IF)
wlan_sta = network.WLAN(network.STA_IF)
server_socket = None
def get_connection():
"""return a working WLAN(STA_IF) instance or None"""
# First check if there already is any connection:
if wlan_sta.isconnected():
return wlan_sta
connected = False
try:
# ESP connecting to WiFi takes time, wait a bit and try again:
time.sleep(3)
if wlan_sta.isconnected():
return wlan_sta
# Read known network profiles from file
profiles = read_profiles()
# Search WiFis in range
wlan_sta.active(True)
networks = wlan_sta.scan()
AUTHMODE = {
0: "open", 1: "WEP", 2: "WPA-PSK", 3: "WPA2-PSK", 4: "WPA/WPA2-PSK"}
for ssid, bssid, channel, rssi, authmode, hidden in sorted(networks, key=lambda x: x[3], reverse=True):
ssid = ssid.decode('utf-8')
encrypted = authmode > 0
print("ssid: %s chan: %d rssi: %d authmode: %s" % (ssid, channel, rssi, AUTHMODE.get(authmode, '?')))
if encrypted:
if ssid in profiles:
password = profiles[ssid]
connected = do_connect(ssid, password)
else:
print("skipping unknown encrypted network")
else: # open
connected = do_connect(ssid, None)
if connected:
break
except OSError as e:
print("exception", str(e))
# start web server for connection manager:
if not connected:
connected = start()
return wlan_sta if connected else None
def read_profiles():
with open(NETWORK_PROFILES) as f:
lines = f.readlines()
profiles = {
}
for line in lines:
ssid, password = line.strip("\n").split(";")
profiles[ssid] = password
return profiles
def write_profiles(profiles):
lines = []
for ssid, password in profiles.items():
lines.append("%s;%s\n" % (ssid, password))
with open(NETWORK_PROFILES, "w") as f:
f.write(''.join(lines))
def do_connect(ssid, password):
wlan_sta.active(True)
if wlan_sta.isconnected():
return None
print('Trying to connect to %s...' % ssid)
wlan_sta.connect(ssid, password)
for retry in range(100):
connected = wlan_sta.isconnected()
if connected:
break
time.sleep(0.1)
print('.', end='')
if connected:
print('\nConnected. Network config: ', wlan_sta.ifconfig())
else:
print('\nFailed. Not Connected to: ' + ssid)
return connected
def send_header(client, status_code=200, content_length=None ):
client.sendall("HTTP/1.0 {} OK\r\n".format(status_code))
client.sendall("Content-Type: text/html\r\n")
if content_length is not None:
client.sendall("Content-Length: {}\r\n".format(content_length))
client.sendall("\r\n")
def send_response(client, payload, status_code=200):
content_length = len(payload)
send_header(client, status_code, content_length)
if content_length > 0:
client.sendall(payload)
client.close()
def handle_root(client):
wlan_sta.active(True)
ssids = sorted(ssid.decode('utf-8') for ssid, *_ in wlan_sta.scan())
send_header(client)
client.sendall("""\
<html>
<h1 style="color: #5e9ca0; text-align: center;">
<span style="color: #ff0000;">
Wi-Fi Client Setup
</span>
</h1>
<form action="configure" method="post">
<table style="margin-left: auto; margin-right: auto;">
<tbody>
""")
while len(ssids):
ssid = ssids.pop(0)
client.sendall("""\
<tr>
<td colspan="2">
<input type="radio" name="ssid" value="{0}" />{0}
</td>
</tr>
""".format(ssid))
client.sendall("""\
<tr>
<td>Password:</td>
<td><input name="password" type="password" /></td>
</tr>
</tbody>
</table>
<p style="text-align: center;">
<input type="submit" value="Submit" />
</p>
</form>
<p> </p>
<hr />
<h5>
<span style="color: #ff0000;">
Your ssid and password information will be saved into the
"%(filename)s" file in your ESP module for future usage.
Be careful about security!
</span>
</h5>
<hr />
<h2 style="color: #2e6c80;">
Some useful infos:
</h2>
<ul>
<li>
Original code from <a href="https://github.com/cpopp/MicroPythonSamples"
target="_blank" rel="noopener">cpopp/MicroPythonSamples</a>.
</li>
<li>
This code available at <a href="https://github.com/tayfunulu/WiFiManager"
target="_blank" rel="noopener">tayfunulu/WiFiManager</a>.
</li>
</ul>
</html>
""" % dict(filename=NETWORK_PROFILES))
client.close()
def handle_configure(client, request):
match = ure.search("ssid=([^&]*)&password=(.*)", request)
if match is None:
send_response(client, "Parameters not found", status_code=400)
return False
# version 1.9 compatibility
try:
ssid = match.group(1).decode("utf-8").replace("%3F", "?").replace("%21", "!")
password = match.group(2).decode("utf-8").replace("%3F", "?").replace("%21", "!")
except Exception:
ssid = match.group(1).replace("%3F", "?").replace("%21", "!")
password = match.group(2).replace("%3F", "?").replace("%21", "!")
if len(ssid) == 0:
send_response(client, "SSID must be provided", status_code=400)
return False
if do_connect(ssid, password):
response = """\
<html>
<center>
<br><br>
<h1 style="color: #5e9ca0; text-align: center;">
<span style="color: #ff0000;">
ESP successfully connected to WiFi network %(ssid)s.
</span>
</h1>
<br><br>
</center>
</html>
""" % dict(ssid=ssid)
send_response(client, response)
try:
profiles = read_profiles()
except OSError:
profiles = {
}
profiles[ssid] = password
write_profiles(profiles)
time.sleep(5)
return True
else:
response = """\
<html>
<center>
<h1 style="color: #5e9ca0; text-align: center;">
<span style="color: #ff0000;">
ESP could not connect to WiFi network %(ssid)s.
</span>
</h1>
<br><br>
<form>
<input type="button" value="Go back!" οnclick="history.back()"></input>
</form>
</center>
</html>
""" % dict(ssid=ssid)
send_response(client, response)
return False
def handle_not_found(client, url):
send_response(client, "Path not found: {}".format(url), status_code=404)
def stop():
global server_socket
if server_socket:
server_socket.close()
server_socket = None
def start(port=80):
global server_socket
addr = socket.getaddrinfo('0.0.0.0', port)[0][-1]
stop()
wlan_sta.active(True)
wlan_ap.active(True)
wlan_ap.config(essid=ap_ssid, password=ap_password, authmode=ap_authmode)
server_socket = socket.socket()
server_socket.bind(addr)
server_socket.listen(1)
print('Connect to WiFi ssid ' + ap_ssid + ', default password: ' + ap_password)
print('and access the ESP via your favorite web browser at 192.168.4.1.')
print('Listening on:', addr)
while True:
if wlan_sta.isconnected():
return True
client, addr = server_socket.accept()
print('client connected from', addr)
try:
client.settimeout(5.0)
request = b""
try:
while "\r\n\r\n" not in request:
request += client.recv(512)
except OSError:
pass
print("Request is: {}".format(request))
if "HTTP" not in request: # skip invalid requests
continue
# version 1.9 compatibility
try:
url = ure.search("(?:GET|POST) /(.*?)(?:\\?.*?)? HTTP", request).group(1).decode("utf-8").rstrip("/")
except Exception:
url = ure.search("(?:GET|POST) /(.*?)(?:\\?.*?)? HTTP", request).group(1).rstrip("/")
print("URL is {}".format(url))
if url == "":
handle_root(client)
elif url == "configure":
handle_configure(client, request)
else:
handle_not_found(client, url)
finally:
client.close()
需要自定义的宏为:
ap_ssid = "WifiManager" # 这是ESP8266 接入点的名称
ap_password = "tayfunulu" # 这是ESP8266 接入点的密码
ap_authmode = 3 # WPA2` # 这是协议类型,可默认为3
main.py
配合模块使用需要修改main.py的源码为:
import wifimgr # 这个模块名称务必要与上述WiFiManager模块文件名一致
wlan = wifimgr.get_connection()
if wlan is None:
print("Could not initialize the network connection.")
while True:
pass # you shall not pass :D
# Main Code goes here, wlan is a working network.WLAN(STA_IF) instance.
print("ESP OK")
这个import的模块名称务必要与上述WiFiManager模块文件名一致 。
WiFi Manger模块测试
通过系列文章第四回中介绍的方式,将main.py和wifimgr.py烧录至ESP8266的Flash中,并进行复位操作,就可以在REPL中看到相应的串口信息提示:
Connect to WiFi ssid WifiManager, default password: tayfunulu and access the ESP via your favourite web browser at 192.168.4.1.
Listening on:('0.0.0', 80)
按照上述提示,使用手机或者有WiFi的电脑,接入Access Point:WifiManager,密码:tayfunulu(如果修改过,请输入自己修改后的密码):
当连接WiFiManager网络成功后,在浏览器地址栏输入IP192.268.4.1
,就会返回得到如下网页:
选择你的网络,并输入PASSWORD,点击Submit
,加载完成后可以跳转到连接成功界面:
同时,REPL也会出现接入WiFi的提示:
显示已经接入WiFi,以及相应的IP,掩码,网关等;
最主要的是,在REPL中显示:
ESP OK
这就说明,在main.py中,已经运行到了最后一句。也就是说已经成功完成了配置WiFi的操作,如果后续有什么功能,就可以继续下去。
结束语
通过Web配置WIFI肯定不是唯一的方法。相对于再源码里面修改WIFI的配置信息来说,这样显得更加人性化,毕竟不是每个人都喜欢捣鼓这些玩意儿。
笔者对HTML不熟悉,有兴趣页面应该可以做的更好看点。
还有,切勿拿来主义,只有学习的态度是不能够的,更重要的是真的去学习。
参考连接
- https://randomnerdtutorials.com/micropython-wi-fi-manager-esp32-esp8266/
- https://github.com/tayfunulu/WiFiManager
2021-01-10;