---
title: "With the STM32 into the Internet of Things"
url: "https://maker.wiznet.io/ssekim/projects/with-the-stm32-into-the-internet-of-things/"
markdown_url: "https://maker.wiznet.io/ssekim/projects/with-the-stm32-into-the-internet-of-things/md"
type: "UCC: User Created Content"
author: "Martin Mohr"
author_url: "https://iotcon.de/blog/iot-konferenz/with-the-stm32-into-the-internet-of-things/"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Martin Mohr"
original_url: "https://iotcon.de/blog/iot-konferenz/with-the-stm32-into-the-internet-of-things/"
published: "2022-08-30"
language: "en"
likes: 5
views: 1056
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# With the STM32 into the Internet of Things

> The STM32 is a true classic: the microcontroller is widely used, inexpensive and ideal for getting started with the Internet of Things.

Original author: Martin Mohr (source: https://iotcon.de/blog/iot-konferenz/with-the-stm32-into-the-internet-of-things/)

## Documents and links

- [Entwickler Magazin](https://github.com/EntwicklerMagazin/Entwickler-Magazin) (code)

## Article

The STM32 is a true classic: the microcontroller is widely used, inexpensive and ideal for getting started with the Internet of Things. So roll up your sleeves and let’s get started: We want to equip the STM32 Nucleo board with Ethernet. Along the way, you'll get plenty of practical tips on what to consider when programming a web server on a microcontroller.

### WIZ5500 Ethernet Controller

In order to connect the Nucleo board to a network, we first need a suitable interface. The WIZ5500 is a hardware Ethernet controller that supports the usual protocols such as TCP, UDP, ICMP, IPv4, ARP, IGMP, and PPPoE. Its operating voltage is 3.3 volts. The Ethernet controller operates at both 10 Mbit and 100 Mbit. As a hobbyist-friendly module, the WIZ5500 costs about 9 euros. The data transfer between the network module and the Nucleo board is done via the SPI interface. This is often used for the communication of microcontrollers with their peripherals. In principle, the data is transmitted clock-synchronously and serially. Table 2 shows how the Nucleo Board must be connected to the network module. It should be noted here that we are using the SPI2 interface of the Nucleo board. Figure 7 shows how to make the connections. To make sure we don’t forget later, we should connect the LAN directly as well. It wouldn’t be the first time that we spent hours looking for a fault—and in the end, it was only a forgotten plug connection.

The WIZ5500 module does not have its own Media Access Control (MAC) address. This means that the MAC must be provided externally. There are two possibilities here: For testing, just take any random sequence, because it would be quite unlikely to hit a MAC that you already have in your own network segment. The second option is to buy a chip that contains a MAC (globally unique). You read this and use it for the WIZ5500. The 24AA025E48 is for example such a chip.

For simple experiments, the first variant is absolutely fine because the MAC address only has to be unique within one network segment. The MAC is not transmitted across router boundaries. If you want to know even more about the WIZ5500 chip, take a look at the data sheet.

---

Source: https://maker.wiznet.io/ssekim/projects/with-the-stm32-into-the-internet-of-things/