Soft Access Point Class

Section below is ESP8266 specific as Arduino WiFi library documentation does not cover soft access point. The API description is broken down into three short chapters. They cover how to setup soft-AP, manage connection, and obtain information on soft-AP interface configuration.

Table of Contents

Set up Network

This section describes functions to set up and configure ESP8266 in the soft access point (soft-AP) mode.

softAP

Set up a soft access point to establish a Wi-Fi network.

The simplest version (an overload in C++ terms) of this function requires only one parameter and is used to set up an open Wi-Fi network.

WiFi.softAP(ssid)

To set up password protected network, or to configure additional network parameters, use the following overload:

WiFi.softAP(ssid, password, channel, hidden, max_connection)

The first parameter of this function is required, remaining four are optional.

Meaning of all parameters is as follows:

  • ssid - character string containing network SSID (max. 63 characters)
  • password - optional character string with a password. For WPA2-PSK network it should be at least 8 character long. If not specified, the access point will be open for anybody to connect.
  • channel - optional parameter to set Wi-Fi channel, from 1 to 13. Default channel = 1.
  • hidden - optional parameter, if set to true will hide SSID.
  • max_connection - optional parameter to set max simultaneous connected stations, from 0 to 8. Defaults to 4. Once the max number has been reached, any other station that wants to connect will be forced to wait until an already connected station disconnects.

Function will return true or false depending on result of setting the soft-AP.

Notes:

  • The network established by softAP will have default IP address of 192.168.4.1. This address may be changed using softAPConfig (see below).
  • Even though ESP8266 can operate in soft-AP + station mode, it actually has only one hardware channel. Therefore in soft-AP + station mode, the soft-AP channel will default to the number used by station. For more information how this may affect operation of stations connected to ESP8266’s soft-AP, please check this FAQ entry on Espressif forum.

softAPConfig

Configure the soft access point’s network interface.

softAPConfig (local_ip, gateway, subnet)

All parameters are the type of IPAddress and defined as follows:

  • local_ip - IP address of the soft access point
  • gateway - gateway IP address
  • subnet - subnet mask

Function will return true or false depending on result of changing the configuration.

Example code:

#include <ESP8266WiFi.h>

IPAddress local_IP(192,168,4,22);
IPAddress gateway(192,168,4,9);
IPAddress subnet(255,255,255,0);

void setup()
{
  Serial.begin(115200);
  Serial.println();

  Serial.print("Setting soft-AP configuration ... ");
  Serial.println(WiFi.softAPConfig(local_IP, gateway, subnet) ? "Ready" : "Failed!");

  Serial.print("Setting soft-AP ... ");
  Serial.println(WiFi.softAP("ESPsoftAP_01") ? "Ready" : "Failed!");

  Serial.print("Soft-AP IP address = ");
  Serial.println(WiFi.softAPIP());
}

void loop() {}

Example output:

Setting soft-AP configuration ... Ready
Setting soft-AP ... Ready
Soft-AP IP address = 192.168.4.22

Manage Network

Once soft-AP is established you may check the number of stations connected, or shut it down, using the following functions.

softAPgetStationNum

Get the count of the stations that are connected to the soft-AP interface.

WiFi.softAPgetStationNum()

Example code:

Serial.printf("Stations connected to soft-AP = %d\n", WiFi.softAPgetStationNum());

Example output:

Stations connected to soft-AP = 2

Note: the maximum number of stations that may be connected to ESP8266 soft-AP is 4 by default. This can be changed from 0 to 8 via the max_connection argument of the softAP method.

softAPdisconnect

Disconnect stations from the network established by the soft-AP.

WiFi.softAPdisconnect(wifioff)

Function will set currently configured SSID and password of the soft-AP to null values. The parameter wifioff is optional. If set to true it will switch the soft-AP mode off.

Function will return true if operation was successful or false if otherwise.

Network Configuration

Functions below provide IP and MAC address of ESP8266’s soft-AP.

softAPIP

Return IP address of the soft access point’s network interface.

WiFi.softAPIP()

Returned value is of IPAddress type.

Example code:

Serial.print("Soft-AP IP address = ");
Serial.println(WiFi.softAPIP());

Example output:

Soft-AP IP address = 192.168.4.1

softAPmacAddress

Return MAC address of soft access point. This function comes in two versions, which differ in type of returned values. First returns a pointer, the second a String.

Pointer to MAC

WiFi.softAPmacAddress(mac)

Function accepts one parameter mac that is a pointer to memory location (an uint8_t array the size of 6 elements) to save the mac address. The same pointer value is returned by the function itself.

Example code:

uint8_t macAddr[6];
WiFi.softAPmacAddress(macAddr);
Serial.printf("MAC address = %02x:%02x:%02x:%02x:%02x:%02x\n", macAddr[0], macAddr[1], macAddr[2], macAddr[3], macAddr[4], macAddr[5]);

Example output:

MAC address = 5e:cf:7f:8b:10:13

MAC as a String

Optionally you can use function without any parameters that returns a String type value.

WiFi.softAPmacAddress()

Example code:

Serial.printf("MAC address = %s\n", WiFi.softAPmacAddress().c_str());

Example output:

MAC address = 5E:CF:7F:8B:10:13

For code samples please refer to separate section with examples dedicated specifically to the Soft Access Point Class.