---
title: "Ethernet_STM"
url: "https://maker.wiznet.io/mayuri/projects/ethernet-stm/"
markdown_url: "https://maker.wiznet.io/mayuri/projects/ethernet-stm/md"
type: "UCC: User Created Content"
author: "Serasidis"
author_url: "https://github.com/Serasidis/Ethernet_STM"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Serasidis"
original_url: "https://github.com/Serasidis/Ethernet_STM"
published: "2022-12-29"
language: "en"
hardware: ["WIZnet W5100 ethernet shield"]
likes: 3
views: 594
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Ethernet_STM

> W5x00 ethernet library for STM32F103 micro-controllers

Original author: Serasidis (source: https://github.com/Serasidis/Ethernet_STM)

## Components

- **WIZnet W5100 ethernet shield** x 1 ([docs](https://www.wiznet.hk/en/open-source-hardware/102-w5100s-ethernetshield.html?search_query=W5100+ethernet+shield&results=84))

## Article

## W5x00 ethernet library for STM32F103 micro-controllers

That library has been ported from the **WIZnet WIZ_Ethernet_Library**, to STM32F103 microcontrollers. The library supports **W5100** and **W5500** Ethernet controllers. The source code has been modified to support the **W5200** too, but has not been tested (yet) on a real W5200 controller.

Ported to STM32F103 on 23 Aug 2015 by **Vassilis Serasidis**

## Library installation

### **Install the library globally**

- Unzip the file **Ethernet_STM-master.zip** into your Arduino IDE directory

> arduino\libraries

and rename the folder **Ethernet_STM-master** to **Ethernet_STM**

In this case the library can be used from the 8-bit and 32-bit Arduino boards (UNO, Nano, DUE etc) and from STM32F1 microcontroller series (for example STM32F103).

#### **Install the library for using it only with STM32F1 series**

- Unzip the file **Ethernet_STM-master.zip** into your Arduino IDE directory

> ...arduino\hardware\Arduino_STM32\STM32F1\libraries

and rename the folder **Ethernet_STM-master** to **Ethernet_STM**

## Selecting the Ethernet type controller (W5100, W5200 or W5500)

For selecting among those tree chips edit the file: `Ethernet_STM\src\utility\w5100.h` and comment-out only the line with the chip you want to use.

By default the **W5500** ethernet controller is selected.

```plaintext
//#define W5100_ETHERNET_SHIELD // Arduino Ethenret Shield and Compatibles ...
//#define W5200_ETHERNET_SHIELD // WIZ820io, W5200 Ethernet Shield 
#define W5500_ETHERNET_SHIELD   // WIZ550io, ioShield series of WIZnet
```

If you edit the **w5100.h** file, save it and re-compile your sketch.

## Selecting W5500 Sockets number and RAM buffer amount

For selecting the Sockets number (1-8) and the RAM buffer amount (1-16 kBytes) for each Socket, edit the file: `Ethernet_STM\src\utility\w5500.h` and change the values you want.

```plaintext
Total RAM buffer is 16 kBytes for Transmitter and 16 kBytes for receiver for 1 Socket.
The Total W5500 RAM buffer is 32 kBytes (16 + 16).
If you use more Sockets then the RAM buffer must be split.
For example: if you use 2 Sockets then all socket must use upto 16 kBytes in total RAM.
So, we have: 
 
   #define MAX_SOCK_NUM 2   // Select two Sockets.
   #define RXBUF_SIZE   8   // The Receiver buffer size will be 8 kBytes
   #define TXBUF_SIZE   8   // The Transmitter buffer size will be 8 kBytes
 
In total we use (2 Sockets)*(8 kBytes) for transmitter + (2 Sockets)*(8 kBytes) for receiver = 32 kBytes.
  
I would prefer to use only 1 Socket with 16 kBytes RAM buffer for transmitter and 16 kByte for receiver buffer.
 
   #define MAX_SOCK_NUM 1   // Select only one Socket
   #define RXBUF_SIZE   16  // Select 16 kBytes Receiver RAM buffer
   #define TXBUF_SIZE   16  // Select 16 kBytes Transmitter RAM buffer
```

Default settings:

```plaintext
#define MAX_SOCK_NUM 8   // Select the number of Sockets (1-8)
#define RXBUF_SIZE   2   // Select the Receiver buffer size (1 - 16 kBytes)
#define TXBUF_SIZE   2   // Select the Transmitter buffer size (1 - 16 kBytes)
```

If you edit the **w5500.h** file, save it and re-compile your sketch.

## Using the Ethernet_STM library

1. Choose the desired ethernet chip you want to use (W5100, W5200 or W5500) from the w5100.h file

2. include this library in your sketch

`#include <Ethernet_STM.h>`

All functions / commands have the same syntax with the stock Arduino Ethernet library.

## PIN Connections

| W5x00 | STM32F103 |
| --- | --- |
| SS | PA4 |
| SCK | PA5 |
| MISO | PA6 |
| MOSI | PA7 |

**DO NOT FORGET TO ADD A RESISTOR 4k7 BETWEEN RESET AND 3.3V (OR RESET AND 5V) PINS ON ETHERNET SHIELD.**

---

Source: https://maker.wiznet.io/mayuri/projects/ethernet-stm/