esp-idf/examples/protocols/http_server/captive_portal

Captive Portal Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example demonstrates a simple captive portal that will redirect all DNS IP questions to point to the softAP and redirect all HTTP requests to the captive portal root page. Triggers captive portal (sign in) pop up on Android, iOS and Windows. Note that the example will not redirect HTTPS requests.

How to Use Example

Before project configuration and build, be sure to set the correct chip target using idf.py set-target <chip_name>.

Hardware Required

• A development board with ESP32/ESP32-S2/ESP32-C3 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for power supply and programming
• WiFi interface

Configure the project

Open the project configuration menu (idf.py menuconfig).

In the Example Configuration menu:

• Set the Wi-Fi configuration.
  • Set SoftAP SSID
  • Set SoftAP Password
  • Set Maximal STA connections

When using the legacy GNU Make build system, set Default serial port under Serial flasher config.

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

I (733) example: Set up softAP with IP: 192.168.4.1
I (743) example: wifi_init_softap finished. SSID:'esp32_ssid' password:'esp32_pwd'
I (753) example: Starting server on port: '80'
I (753) example: Registering URI handlers
I (763) example_dns_redirect_server: Socket created
I (763) example_dns_redirect_server: Socket bound, port 53
I (773) example_dns_redirect_server: Waiting for data
I (1873) wifi:new:<1,1>, old:<1,1>, ap:<1,1>, sta:<255,255>, prof:1
I (1873) wifi:station: e8:84:a5:18:8f:80 join, AID=1, bgn, 40U
I (2203) example: station e8:84:a5:18:8f:80 join, AID=1
I (2833) example_dns_redirect_server: Received 50 bytes from 192.168.4.2 | DNS reply with len: 66
I (2843) example_dns_redirect_server: Waiting for data
I (3043) example_dns_redirect_server: Received 39 bytes from 192.168.4.2 | DNS reply with len: 55
I (3043) example_dns_redirect_server: Waiting for data
I (3043) example_dns_redirect_server: Received 42 bytes from 192.168.4.2 | DNS reply with len: 58
I (3053) example_dns_redirect_server: Waiting for data
W (3203) wifi:<ba-add>idx:4 (ifx:1, e8:84:a5:18:8f:80), tid:0, ssn:9, winSize:64
I (3533) example: Redirecting to root
I (5693) example_dns_redirect_server: Received 37 bytes from 192.168.4.2 | DNS reply with len: 53
I (5693) example_dns_redirect_server: Waiting for data
I (5783) example_dns_redirect_server: Received 46 bytes from 192.168.4.2 | DNS reply with len: 62
I (5783) example_dns_redirect_server: Waiting for data
I (6303) example_dns_redirect_server: Received 41 bytes from 192.168.4.2 | DNS reply with len: 57
I (6303) example_dns_redirect_server: Waiting for data
I (6303) example_dns_redirect_server: Received 41 bytes from 192.168.4.2 | DNS reply with len: 57
I (6313) example_dns_redirect_server: Waiting for data
I (6593) example: Redirecting to root
I (9623) example: Redirecting to root
I (12913) example: Redirecting to root
I (13263) example_dns_redirect_server: Received 34 bytes from 192.168.4.2 | DNS reply with len: 50
I (13273) example_dns_redirect_server: Waiting for data
I (13273) example_dns_redirect_server: Received 34 bytes from 192.168.4.2 | DNS reply with len: 50
I (13283) example_dns_redirect_server: Waiting for data
I (16303) example_dns_redirect_server: Received 32 bytes from 192.168.4.2 | DNS reply with len: 48
I (16303) example_dns_redirect_server: Waiting for data
I (18073) example: Redirecting to root
I (18273) example_dns_redirect_server: Received 34 bytes from 192.168.4.2 | DNS reply with len: 50
I (18273) example_dns_redirect_server: Waiting for data
I (18273) example_dns_redirect_server: Received 34 bytes from 192.168.4.2 | DNS reply with len: 50
I (18283) example_dns_redirect_server: Waiting for data
I (20683) example_dns_redirect_server: Received 42 bytes from 192.168.4.2 | DNS reply with len: 58
I (20683) example_dns_redirect_server: Waiting for data
I (20753) example: Redirecting to root
I (21323) example: Redirecting to root
I (22683) example_dns_redirect_server: Received 48 bytes from 192.168.4.2 | DNS reply with len: 64
I (22693) example_dns_redirect_server: Waiting for data
I (23443) example_dns_redirect_server: Received 48 bytes from 192.168.4.2 | DNS reply with len: 64
I (23453) example_dns_redirect_server: Waiting for data
I (23473) example: Serve root
I (23503) example_dns_redirect_server: Received 48 bytes from 192.168.4.2 | DNS reply with len: 64
I (23513) example_dns_redirect_server: Waiting for data