Use MicroPython development ESP32 (04): Use wireless networks and WebREPL

purpose

ESP32 a major feature is support for wireless networks, this article will introduce the use MicroPython setup / wireless network connection.

Wireless local area network (WLAN)

Function Description

MicroPython used mainly uses a wireless network networkmodule WLANtype, the specific function as follows:

• class network.WLAN(interface_id)
  The constructor for declaring objects WLAN, optional parameters network.STA_IF(connected to an existing wireless network), network.AP_IF(as the network access point);
• WLAN.active([is_active])
  Do not fill the parameters used to return the state of the wireless network function, fill in Truethe Wi-Fi enabled, fill Falsedeactivate the wireless network;
• WLAN.connect(ssid=None, password=None, *, bssid=None)
  The STA mode is used to connect to wireless networks, parameters are ssidnetwork name, passwordpassword, bssidMAC address of the network device;
• WLAN.disconnect()
  For disconnecting the current network connection;
• WLAN.scan()
  Wireless networks available in the environment in a scanning STA mode, returning a list indicating the tuple consisting of wireless network information, wireless network information in the following format:
  (ssid, bssid, channel, RSSI, authmode, hidden)
  BSSID expressed in binary form, can be used ubinascii.hexlify () is converted to ASCII format;
  Channel is channel number, 2.4G network channel number from 1 to 13, based on the channel may cause contamination, often taking 1,6,11;
  the RSSI signal strength, the smaller the value the better the signal;
  the AuthMode encryption mode, is not of 0 – open, 1 – WEP, 2 – WPA-PSK, 3 – WPA2-PSK, 4 – WPA/WPA2-PSK;
  hidden indicate whether the wireless network False – 0 – visible – 可见的hidden , True – 1 – hidden –隐藏的;
• WLAN.status([param])
  Return to the Network work state does not fill parameters:
  STAT_IDLE - Wi-Fi is not turned on;
  STAT_CONNECTING - Connecting;
  STAT_WRONG_PASSWORD - connection failed because of wrong password;
  STAT_NO_AP_FOUND - access point is not found;
  STAT_CONNECT_FAIL - connection failed for other reasons;
  STAT_GOT_IP - successful IP connection ;
  the STA mode may also be filled in 'rssi'as a parameter to get the current network signal strength;
• WLAN.isconnected()
  If the STA mode has an IP network and returns True;
  AP mode if the access device returns True;
• WLAN.ifconfig([(ip, subnet, gateway, dns)])
  Without parameters will return the current network device parameter, the parameter will be a tuple organization with four items, parameters are the IP address, subnet mask, gateway address, DNS server address;
  may be provided with parameters used when the device network parameters, for example in the following manner:
  nic.ifconfig(('192.168.0.4', '255.255.255.0', '192.168.0.1', '8.8.8.8'))
• WLAN.config('param')
WLAN.config(param=value, ...)
  Device used to query or modify network parameters, parameters required by the designated keyword manner, the available parameters are as follows:
  MAC - address of a physical device
  essid - ap network name mode
  channel - channel number
  hidden - is hidden
  authmode - encryption
  password - ap mode password
  dhcp_hostname - dhcp hostname

Demo

STA mode

image above connection I called (SSID) AAA, the password is 12345678 wireless network, even after the network print IP, subnet mask, gateway, DNS server information.

AP mode

image above-enabled wireless access point, the network name is lalala, encryption is WPA / WPA2-PSK, the password is 12345678;

WebREPL

All interact through the serial port and the development board before the presentation of the article, after the network-enabled, we can interact through a network, the following presentation:

on the interactive map is made by a browser to access the IP address of the development board, when entering the password above, and Linux habits as the input will not be displayed. After a successful login press Ctrl + Bcan enter the Shell debugging. In this tool, you can also transfer files.

Need to make before using the tool development board settings:

Enter the password and port number is set, the default port number can also be the default case of default port number is 8266. For webrepl settings are saved in a file, reboot the device also effective. You can use webrepl.stop () method to close the service. You can write a network of automatic initialization code is stored main.pyinto the module, so that after the next time you start to debug directly through the network.

WebREPL Download: https://github.com/micropython/webrepl
WebREPL online hosted version Address: http://micropython.org/webrepl

to sum up

Wireless networking is relatively simple to use, more content can refer to the following links:
http://docs.micropython.org/en/latest/library/network.WLAN.html