yskim96/esp32-arduino-espidf-comp-wifirepeater

ESP32 WiFi Repeater using Arduino as a component of ESP-IDF

Get Started

The following are the steps required to run this project on the ESP32 and turn it into a WiFi repeater.

Step 1 - Download and setup ESP-IDF

Follow the official setup guide for the ESP-IDF v3.3: https://docs.espressif.com/projects/esp-idf/en/v3.3/get-started/index.html

Step 2 - Get lwIP library with NAT

Download the repository of the NAT lwIP library using the following command:

git clone https://github.com/jonask1337/esp-lwip.git

Note: It is important to clone the repository. If it is only downloaded it will be replaced by the orginal lwIP library during the build.

Step 3 - Replace original ESP-IDF lwIP library with NAT lwIP library

1. Go to the folder where the ESP-IDF is installed.
2. Rename or delete the esp-idf/component/lwip/lwip directory.
3. Move the lwIP library with NAT repository folder from Step 2 to esp-idf/component/lwip/
4. Rename the lwIP library with NAT repository folder from esp-lwip to lwip.

Step 4 - Get this project

Clone this repository using the following command:

git clone https://github.com/jonask1337/esp32-arduino-espidf-comp-wifirepeater.git

Step 5 - Setup Arduino as component of ESP-IDF

Based on instruction from: https://github.com/espressif/arduino-esp32/blob/master/docs/esp-idf_component.md

1. Change into the esp32-arduino-espidf-comp-wifirepeater project folder

2. In the project folder, create a folder called components and clone this repository inside

   mkdir -p components && \
   cd components && \
   git clone https://github.com/espressif/arduino-esp32.git arduino && \
   cd arduino && \
   git submodule update --init --recursive && \
   

Step 6 - Build and flash project

You should be now able to build the project and flash it to the esp32.

For this either use idf.py flash (CMake build system) or make flash (make build system).

For more details on building and flashing esp-idf projects see the official Get Started guide for ESP-IDF from Step 1.

Fix Compilation Errors

When building the esp-idf project it may come to some compilation errors due to incompatibilities with components.

Error 1

• Error output:

      /home/jonas/test_arduino_wifirepeater_setup/esp-idf/components/lwip/lwip/src/core/ipv6/nd6.c: 
      In function 'nd6_input': 
      /home/jonas/test_arduino_wifirepeater_setup/esp-idf/components/lwip/lwip/src/core/ipv6/nd6.c:565:39: error: 
      incompatible types when initializing type 'const ip_addr_t * {aka const struct ip_addr *}' 
      using type'ip_addr_t {aka struct ip_addr}' const ip_addr_t *addr = dns_getserver(s);
  

• Fix: In file esp-idf/components/lwip/lwip/src/core/ipv6/nd6.c:565

       ...
       // const ip_addr_t *addr = dns_getserver(s);
       ip_addr_t addr = dns_getserver(s);
       // if(ip_addr_cmp(addr, &rdnss_address)) {
       if(ip_addr_cmp(&addr, &rdnss_address)) {
       ...

Error 2

• Error output:

       home/jonas/test_arduino_wifirepeater_setup/esp-idf/components/tcpip_adapter/tcpip_adapter_lwip.c: 
       In function 'tcpip_adapter_get_dns_info':
       /home/jonas/test_arduino_wifirepeater_setup/esp-idf/components/tcpip_adapter/tcpip_adapter_lwip.c:797:16: 
       error: incompatible types when assigning to type 'const ip_addr_t * 
       {aka const struct ip_addr *}' from type 'ip_addr_t {aka struct ip_addr}'
       dns_ip = dns_getserver(type);
  

• Fix: In file esp-idf/components/tcpip_adapter/tcpip_adapter_lwip.c:778

      // const ip_addr_t*  dns_ip = NULL;
      ip_addr_t dns_ip;
      ...
      if (tcpip_if == TCPIP_ADAPTER_IF_STA || tcpip_if == TCPIP_ADAPTER_IF_ETH) {
          dns_ip = dns_getserver(type);
          //if (dns_ip != NULL) {
          //    dns->ip = *dns_ip;                                                                             
          //}
          dns->ip = dns_ip;
      ...

Configuration

In the main/main.cpp file change the values of the ssid and password variables to the credentials of the WIFI network the ESP32 should connect to.

By Default the DNS-Server which is offerd to clients connecting to the ESP32 AP is set to 8.8.8.8. Replace the value of the MY_DNS_IP_ADDR with your desired DNS-Server IP address (in hex) if you want to use a different one.