STM32 Ethernet Example – HTTP Server Part 1

This is the Series of tutorials on the STM32 Microcontroller. The aim of this series is to provide easy and practical examples that anyone can understand. In this article, we are going to see the STM32 Ethernet Example program which runs a simple HTTP server.

Hardware Required

• STM32F767Zi Nucleo Board
• Ethernet Cable
• Router

STM32 Ethernet Example

In this tutorial, we are going to create a simple HTTP web server in the STM32. Then we are going to access the web server through the ethernet port. Let’s get started.

Project Creation

Create the new project in STM32CubeIDE. Then in the .ioc file, Click “Connectivity” –> “ETH“. Set the Mode as RMII. Please refer to the below image.

Now we need to modify the pins based on our Nucleo board. In our STM32F767Zi Nucleo board, the below pins are connected to the ethernet port.

Pin Name	Pin Function
PA1	RMII Reference Clock (ETH_REF_CLK)
PA2	RMII MDIO (ETH_MDIO)
PC1	RMII MDC (ETH_MDC)
PA7	RMII RX Data Valid (ETH_CRS_DV)
PC4	RMII RXD0 (ETH_RXD0)
PC5	RMII RXD1 (ETH_RXD1)
PG11	RMII TX Enable (ETH_TX_EN)
PG13	RXII TXD0 (ETH_TXD0)
PB13	RMII TXD1 (ETH_TXD1)

But in the STM32CubeIDE, PG13, and PG11 are not enabled. Instead, other pins are used. Change the ETH_TXD0 pin to PG13 and ETH_TX_EN pin to PG11. The rest of the other pins are same as the STM32F767Zi board pins. Ensure you enabled all the pins like the below image.

Then Click the “Middleware” –> “LWIP” and Enable that. Then, In the Platform Settings, Select the LAN8742 as a Driver_PHY. Refer to the below image.

Now, we will set the IP address. Click the General Settings, and Disable the LWIP_DHCP(DHCP Module). Then set the IP address, Netmask, and Gateway like the below image.

Now our IP address is 192.168.1.25. Then click the HTTPD and enable the LWIP_HTTPD. Refer to the below image.

We are going to use the User LED for blinking. So, enable the PB0 pin as GPIO Output. Refer to the below image.

Now, click the Clock Configuration. The clock is not configured properly. It is asking me to run the automatic clock issue resolver. Click Yes (If you don’t want to set it manually). You can setup manually also based on your project. Refer to the below image.

It has resolved the clock issues automatically. That’s it. We have configured it. Save this ioc file and it will auto-generate the code for us. You can see the video explanation here if you are confused.

Source Code – STM32 Ethernet Example

Add the below code to the main.c file between USER CODE BEGIN Includes and USER CODE END Includes).

You can get the entire project code from GitHub.

/* USER CODE BEGIN Includes */
#include "lwip/apps/httpd.h"
/* USER CODE END Includes */

Add the below code between USER CODE BEGIN 2 and USER CODE END 2. This code will initialize the HTTP server.

  /* USER CODE BEGIN 2 */
  httpd_init();
  uint32_t count = 0;
  /* USER CODE END 2 */

Add the below code between the while (1) and USER CODE END WHILE. This MX_LWIP_Process() function process the HTTP server. And to know that process is running perfectly without any issues, we are toggling the PB0 LED every 10000 times.

  /* USER CODE BEGIN WHILE */
  while (1)
  {
    MX_LWIP_Process();
    count++;
    if( count >= 10000)
    {
      HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_0 );    //Green LED Toggle
      count = 0;
    }
    /* USER CODE END WHILE */

Now build the source code.

You will get the error called “/Middlewares/Third_Party/LwIP/src/include/lwip/apps/httpd_opts.h:386:27: fatal error: fsdata_custom.c: No such file or directory“. We will have to generate this file based on our webpage. Now we will do that.

MakeFsData

Download this zip file and extract it. To run this makefsdata.pl, we need to install Perl on our machine. Download and install Perl from the official website.

Then open the command terminal and run the following command under the extracted directory.

perl makefsdata.pl

You should get the output like below and it should generate the fsdata_custom.c and fsdata.c files.

perl makefsdata.pl
opening root directory, found the following files and all subdirectories to process:
  404.html index.html


Starting convert files to arrays process:
  Adding file: 404.html
  /404.html, Bytesread = 1745

  Adding file: index.html
  /index.html, Bytesread = 1413

Now we have fsdata_custom.c and fsdata.c files. Copy that and add those files to the Middlewares –> Third_Party –> LwIP –> Src –> apps –> HTTP. Refer to the below image.

Now we will exclude those two files from the build. Select those two files and right-click. Then click Resource configurations –> Exclude from build. Refer to the below image.

Now select Debug and Release then click OK. Refer to the below image.

That’s it. Now build the project. There should not be any errors. Flash the bin file to the STM32F767Zi.

Connection

Connect the LAN cable (RJ45 cable) to the STM32F7 and Router. Now, ensure your machine or mobile is connected to the same router through wifi or ethernet cable. Refer to the below image.

Note: Ensure that the jumpers are connected in JP6 and JP7 in the STM32F767Zi Nucleo board.

STM32 Ethernet Demo

Now restart the STM32F7 Necleo. You should see the LED is blinking fastly. Then when you access this “192.168.1.25” from your browser, you should see the webpage. When you access the “192.168.1.25/test“, you should see the 404 error page. We have added only two HTML pages. You can add many pages to the fsdata_custom.c and fsdata.c files by using this process. Please check the below video demo.

Video Explanation

Added Soon

You can also read the below tutorials.

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RTX RTOS Tutorials	Interrupts Basics
I2C Protocol – Part 1 (Basics)	I2C Protocol – Part 2 (Advanced Topics)
STM32 Tutorials	LPC2148 (ARM7) Tutorials
PIC16F877A Tutorials	8051 Tutorials
Unit Testing in C Tutorials	ESP32-IDF Tutorials
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STM32F7 Bootloader Tutorials	Raspberry PI Pico Tutorials
STM32F103 Bootloader Tutorials	RT-Thread RTOS Tutorials
Zephyr RTOS Tutorials – STM32	Zephyr RTOS Tutorials – ESP32
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