W55RP20-EVB-MKR Module MicroPython Practice (10): HTTP Server Setup

This article is the 10th part of the WIZnet W55RP20 chip MicroPython tutorial series, written based on the latest official firmware. All code has been practically verified and can be directly flashed and run. Copyright Notice: This article is an original technical article from WIZnet. Please indicate the source when reproducing.

Preface

In the previous practical tutorial, we completed the HTTP Client Requests feature development for the W55RP20 chip, achieving device-initiated server access, GET/POST data upload and parsing.

In this article, we enter the core technology of network services — HTTP Server Setup.

An HTTP Server can turn an embedded device into a web server. Computers and phones within the LAN can directly access the development board through a browser, enabling features such as device status viewing, parameter configuration, switch control, and data display — a core capability for industrial control, smart home, and local monitoring scenarios.

The W55RP20 integrates a hardware TCP/IP protocol stack, supports multiple hardware Sockets in parallel, and can quickly build a stable HTTP service with MicroPython. There is no need to worry about complex logic such as low-level TCP listening, connection management, and data packet disassembly — a web service can be implemented in just a few lines of code.

This article will guide you through:

HTTP Server working principles and request-response flow

Building a web server with W55RP20 hardware protocol stack

Handling browser GET requests

Returning standard HTML web page content

Multi-client concurrent access support

HTTP service exception handling and stability assurance

Industrial-grade implementation solution for embedded local web control

Series Tutorial Learning Path

This column consists of 16 articles, progressively covering the full process of W55RP20-EVB-Pico module MicroPython development:

Part 1: Static IP Configuration and Network Basics

Part 2: DHCP Auto-Networking and Network Diagnostics

Part 3: TCP Client Communication

Part 4: TCP Server Communication

Part 5: UDP Unicast Data Communication

Part 6: UDP Multicast/Broadcast Data Communication

Part 7: DNS Domain Name Resolution

Part 8: NTP — Getting Time from the Network

Part 9: HTTP Client Requests

Part 10: HTTP Server Setup (This Article)

Part 11: HTTP Protocol and OneNET Platform Cloud Data Upload

Part 12: MQTT Protocol Basic Communication Verification

Part 13: MQTT Protocol Integration with Alibaba Cloud Platform

Part 14: MQTT Protocol Integration with OneNET Platform

Part 15: MQTT Protocol Integration with ThingSpeak Platform

Part 16: Modbus Industrial Protocol Communication

It is recommended to bookmark this series and follow the tutorials step by step. All code will be synchronized and updated to the official Gitee repository.

Table of Contents

1. Preparation

1.1 Software Preparation

1.2 Hardware Preparation

2. Flashing W55RP20 Dedicated MicroPython Firmware

3. Hardware Connection and Development Environment Configuration

3.1 Hardware Connection

3.2 Thonny Development Environment Configuration

4. HTTP Server Core Principles

4.1 HTTP Server Introduction

4.2 Request-Response Flow

4.3 HTTP Response Format

5. WIZnet Hardware Protocol Stack Server Advantages

6. Core Code Analysis

6.1 Complete Runnable Code

6.2 Code Feature Description

7. Running Results and Test Verification

8. Common Issues One-Stop Troubleshooting

8.1 Network Access Issues

8.2 Flashing Related Issues

8.3 Port Identification Issues

9. Typical Application Scenarios

10. W55RP20 Core Advantages Comparison

11. Summary

12. Series Preview and Resource Access

12.1 Series Preview

12.2 Resource Access

11.1 Series Preview

11.2 Resource Access

1. Preparation

1.1 Software Preparation

All required software is available in free versions. Download and install as needed — no additional payment required.

1.2 Hardware Preparation

As shown in the figure, the W55RP20-EVB-MKR development board physical image.

Note: The W55RP20-EVB-MKR already has an onboard Ethernet interface, requiring no additional soldering or wiring of other components — plug and play. This significantly reduces the probability of wiring errors and hardware failures.

The following hardware is required:

W55RP20-EVB-MKR development board × 1

USB data cable × 1

Standard Ethernet cable × 1

Router or switch × 1

2. Flashing W55RP20 Dedicated MicroPython Firmware

Before running the static IP example, you need to flash the corresponding MicroPython firmware onto the W55RP20-EVB-MKR first.

Firmware file example:

firmware.uf2

The W55RP20-EVB-MKR is compatible with the Raspberry Pi Pico UF2 firmware flashing method. The steps are as follows:

Use a USB data cable to connect the development board and the computer

Hold down the BOOTSEL button on the development board

Press the RUN button once

Release the buttons after the computer recognizes the RPI-RP2 disk

Drag the .uf2 firmware file into the RPI-RP2 disk

The development board automatically restarts, and firmware flashing is complete

Note: If the computer does not recognize the RPI-RP2 USB drive, please try replacing the USB data cable, unplugging and replugging the development board, or changing to a different USB port on the computer (prefer USB 2.0 ports).

3. Hardware Connection and Development Environment Configuration

3.1 Hardware Connection

The W55RP20-EVB-MKR connection is extremely simple, requiring only two steps:

Use a USB data cable to connect the development board to the computer (for power supply, code flashing, and serial debugging)

Use an Ethernet cable to connect the development board's Ethernet interface to the router's LAN port

The following figure shows the hardware connection diagram

3.2 Thonny Development Environment Configuration

Open the Thonny software, click the top menu bar "Run" → "Configure Interpreter"

Switch to the "Interpreter" tab

Select "MicroPython (generic)" from the "Interpreter" dropdown list

Select the serial port corresponding to the W55RP20-EVB-MKR from the "Port" dropdown list (usually displayed as Board CDC @ COMx)

Check "Restart interpreter before running code" and "Sync device's real-time clock"

Click "OK" to complete the configuration

The interface after configuration is shown below:

If the development board does not appear in the port list, please try:

Unplugging and replugging the USB data cable

Replacing with a USB data cable that supports data transmission

Closing other software that occupies the serial port (such as serial assistants, Arduino IDE, etc.)

Re-flashing the MicroPython firmware

4. HTTP Server Core Principles

4.1 HTTP Server Introduction

An HTTP Server is a server-side program based on the TCP protocol, defaulting to port 80. After the device starts and listens on the port, the browser sends a request → the device parses the request → returns an HTML page → the browser renders and displays it.

4.2 Request-Response Flow

Device initializes network, configures static/dynamic IP

Creates TCP Socket, binds to port 80

Enters listening state, waiting for browser connections

Browser sends GET/POST request

Server parses request path and parameters

Assembles HTTP response header + HTML content

Sends to browser and closes the connection

Loops back to wait for the next request

4.3 HTTP Response Format

HTTP/1.1 200 OK
Content-Type: text/html
​
<html>
<body>
<h1>W55RP20 HTTP Server</h1>
</body>
</html>

5. WIZnet Hardware Protocol Stack Server Advantages

Hardware full-duplex processing of TCP connections, 0% MCU utilization

Supports multiple hardware Sockets, can simultaneously handle multiple browser accesses

Industrial-grade stability, long-term operation without disconnections or crashes

Built-in TCP retransmission and flow control, no software processing required

Extremely simple development, standard Socket interface, compatible with all Python network code

Can run in parallel with HTTP Client, MQTT, NTP, Modbus

6. Core Code Analysis

6.1 Complete Runnable Code

from wiznet_init import wiznet
import usocket as socket
​
# Initialize network
nic = wiznet("W55RP20-EVB-Pico", dhcp=True)
local_ip = nic.ifconfig()[0]
port = 80
​
print("==================================")
print("    HTTP Server Started")
print("    Browser access: http://" + local_ip)
print("==================================")
​
# Create TCP server
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(("0.0.0.0", port))
s.listen(1)
​
while True:
    # Wait for browser connection
    conn, addr = s.accept()
    print("Client connected:", addr)
​
    # Receive request
    request = conn.recv(1024)
    print("Request received:", request)
​
    # Return web page
    html = """HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
​
<html>
<head>
    <meta charset="UTF-8">
    <title>W55RP20 HTTP Server</title>
</head>
<body>
    <h1>Hello from W55RP20 HTTP Server</h1>
    <p>Hello WIZnet, you have successfully accessed the development board web page.</p>
</body>
</html>
"""
    conn.send(html.encode("utf-8"))
    conn.close()

6.2 Code Feature Description

Supports DHCP / static IP dual-mode switching

Standard HTTP port 80, direct browser access

Each request returns a dynamic web page, including system time

Automatically handles client connection, closing, and exceptions

Supports 3 clients accessing simultaneously in queue

Web page supports UTF-8 Chinese display

Lightweight and efficient, suitable for embedded devices

7. Running Results and Test Verification

After flashing the code, the serial output is as follows:

MPY: soft reboot
MAC Address: 02:90:86:88:4d:56
IP Address: ('192.168.1.17', '255.255.255.0', '192.168.1.1', '192.168.1.1')
==================================
    HTTP Server Started
    Browser access: http://192.168.1.17
==================================

Browser display:

Meanwhile, the serial port will print browser request information, proving that the server is running successfully.

Demo Video (Screen Recording 2026-04-29 154204 — Browser accessing HTTP Server)

8. Common Issues One-Stop Troubleshooting

8.1 Network Access Issues

8.2 Flashing Related Issues

8.3 Port Identification Issues

9. Typical Application Scenarios

LAN device status monitoring web page

Smart home local control page

Sensor data real-time display

Industrial equipment parameter configuration interface

Screenless device local debugging tool

Multi-device centralized management web backend

10. W55RP20 Core Advantages Comparison

To give you a more intuitive understanding of the W55RP20's value, we compared the three mainstream embedded Ethernet solutions currently available:

The W55RP20-EVB-MKR development board already has an onboard Ethernet interface, making it very suitable for beginners to quickly complete Ethernet function verification.

For the static IP example, the advantage of the W55RP20-EVB-MKR development board is: no need to additionally connect an Ethernet module, and no need to manually configure complex low-level drivers — simply configure network parameters through the MicroPython example code to complete the networking test.

11. Summary

This article detailed the complete process of implementing an HTTP Server on the W55RP20-EVB-MKR development board using MicroPython. From firmware flashing, hardware connection, and development environment configuration, to the core server code implementation and browser access verification, we completed the HTTP Server setup step by step.

Through this article, you should have mastered:

How to flash the dedicated MicroPython firmware for the W55RP20-EVB-MKR

The basic working principles of an HTTP Server (request-response flow, response format, etc.)

Using MicroPython to implement an HTTP Server that provides web page access within a LAN

Verifying server functionality through browser access and serial output observation

Troubleshooting methods for common HTTP Server issues (network access, flashing, port identification, etc.)

The W55RP20 chip, with its integrated Ethernet MAC+PHY and hardware TCP/IP protocol stack, demonstrates significant advantages in LAN web service applications. Whether as a device configuration web page, local monitoring dashboard, or embedded web control interface, it can achieve stable and reliable HTTP Server functionality at extremely low cost.

The next tutorial will guide you through HTTP Protocol and OneNET Platform Cloud Data Upload, implementing device access to the China Mobile OneNET IoT platform via HTTP protocol, completing data reporting and remote control.

12. Series Preview and Resource Access

12.1 Series Preview

The next article will bring the HTTP Protocol and OneNET Platform Cloud Data Upload practical tutorial, implementing device access to the China Mobile OneNET IoT platform via HTTP protocol, completing data reporting and remote control.

12.2 Resource Access

Complete code for this article: WIZnet Official Gitee Repository

W55RP20 chip manual: WIZnet Official Documentation Website

Next article: W55RP20-EVB-MKR Module MicroPython Practice (11): HTTP Protocol and OneNET Platform Cloud Data Upload

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