eth2wlan

The project enables ethernet to Wi-Fi data forwarding function (Ethernet to Wi-Fi bridge). It supports both station and access point mode.

Overview

The similarities on MAC layer between Ethernet and Wi-Fi make it easy to forward packets from Ethernet to Wi-Fi and vice versa. This example illustrates how to implement a simple "router" which only supports forwarding packets between Ethernet port and Wi-Fi interface.

In this example, ESP32 works like a bridge between Ethernet and Wi-Fi, and it won't perform any actions on Layer3 and higher layer, which means there's no need to initialize the TCP/IP stack.

Hardware

To run this example, it's recommended that you have an official ESP32 Ethernet development board - ESP32-Ethernet-Kit. This example should also work for 3rd party ESP32 board as long as it's integrated with a supported Ethernet PHY chip. Up until now, ESP-IDF supports up to four Ethernet PHY: LAN8720, IP101, DP83848 and RTL8201, additional PHY drivers should be implemented by users themselves.

Besides that, esp_eth component can drive third-party Ethernet module which integrates MAC and PHY and provides common communication interface (e.g. SPI, USB, etc). This example will take the DM9051 as an example, illustrating how to install the Ethernet driver in the same manner.

Common Pin Assignments

See here the common pin assignments for Ethernet examples.

Common Boards

• wESP32

  Parameter	Value
  type	LAN87XX
  MDC	16
  MDIO	17
  PHY Address	0

• Olimex ESP32-POE

  Parameter	Value
  type	LAN87XX
  MDC	23
  MDIO	18
  PHY Address	0
  Power PIN	12

• Olimex ESP32-EVB

  Parameter	Value
  type	LAN87XX
  MDC	23
  MDIO	18
  PHY Address	0

• LILYGO TTGO T-Internet-POE ESP32-WROOM LAN8270A Chip

  Parameter	Value
  type	LAN87XX
  MDC	23
  MDIO	18
  PHY Address	0

• OpenHacks LAN8720

  Parameter	Value
  type	LAN87XX
  MDC	23
  MDIO	18
  PHY Address	1

• Wireless Tag WT32-ETH01

  Parameter	Value
  type	LAN87XX
  MDC	23
  MDIO	18
  PHY Address	1
  Power PIN	16

Configuration

docker-compose run --rm idf idf.py menuconfig

In addition to the common configurations, you might need to update the default values of following configuration:

In the Ethernet to WLAN Configuration menu:

• Set the SSID and passphrase for Wi-Fi interface under Wi-Fi SSID and Wi-Fi Password.

Build and Flash

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

docker-compose run --rm idf idf.py build 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.

Troubleshooting

See here the common troubleshooting for Ethernet examples.

• If you got error message like WiFi send packet failed when running the example, you may need to enlarge the value of FLOW_CONTROL_WIFI_SEND_DELAY_MS in "ethernet_example_main.c", because Ethernet process packets faster than Wi-Fi on ESP32.
• If you got error message like send flow control message failed or timeout when running the example, you may need to enlarge the value of FLOW_CONTROL_QUEUE_LENGTH in "ethernet_example_main".