---
title: "W55RP20-S2E Web Server Example (MicroPython)"
url: "https://maker.wiznet.io/Grace_Koo/projects/w55rp20-s2e-web-server-example-micropython/"
markdown_url: "https://maker.wiznet.io/Grace_Koo/projects/w55rp20-s2e-web-server-example-micropython/md"
type: "WCC: WIZnet Created Content"
author: "Grace"
author_url: "https://maker.wiznet.io/Grace_Koo/"
original_author: "Grace_Koo"
published: "2026-02-06"
language: "en"
tags: ["W55RP20", "MicroPython", "wow-contest-ref"]
hardware: ["WIZnet W5500"]
likes: 0
views: 828
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# W55RP20-S2E Web Server Example (MicroPython)

> This example demonstrates Web Server on W55RP20 S2E via UART/SPI using MicroPython on a Raspberry Pi Pico (Master)

Original author: Grace_Koo

## Components

- **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500))
- Software: **MicroPython** ([docs](http://micropython.org/))

WIZnet parts: W5500 ([Datasheet](https://docs.wiznet.io/Product/Chip/Ethernet/W5500/datasheet?utm_source=maker&utm_medium=project&utm_campaign=w5500), [product hub](https://maker.wiznet.io/products/w5500/))

## Documents and links

- [GitHub : W55RP20-S2E_master_Micropython](https://github.com/WIZnet-ioNIC/WoW-io-Design-Contest/tree/main/MicroPython) (code)

## Article

## How to Web Server Example (MicroPython)

This program demonstrates how to turn the W55RP20 S2E board into a simple Web Server via UART or SPI interface. The Raspberry Pi Pico (Host) configures the W55RP20 S2E as a TCP Server (OP1) listening on Port 80. When a PC or Mobile web browser connects to the module's IP, the Pico serves a simple HTML page.

## Step 1: Prepare software

The following software is required to run and test the MicroPython example.

- [**Thonny**](https://thonny.org/) : An integrated development environment for MicroPython. used to write, upload, and run code.

- Public Test Server: We will use `httpbin.org` (a simple HTTP Request & Response Service) for testing, so no local server software is strictly required.

⚠️ Browser Warning (Chrome/Edge): Modern browsers like Chrome try to open multiple connections (caching, favicon). This simple server handles one connection at a time.

- Fix: Use Incognito Mode (Private Window) or press Ctrl+F5 if the page hangs.

## Step 2: Prepare hardware

1. Connect GPIO13 according to the selected UART/SPI mode of the W55RP20 EVB Pico, as illustrated below.

| GPIO13 Pin | Desc |
| --- | --- |
| LOW(GND) | UART mode (default) |
| HIGH(3.3V) | SPI mode |

2. Connect the Raspberry Pi Pico and the W55RP20 EVB Pico using jumper wires as shown below, depending on the selected UART/SPI mode.

- Important Note on Mode Switching: In this example setup, GPIO 13 of the W55RP20 EVB Pico is physically connected to GPIO 13 of the Raspberry Pi Pico. The Host Pico sets the mode (High/Low) automatically based on the software configuration.

- If you change the **`**MODE**`** in the code (e.g., UART ↔ SPI): You MUST reset both boards (Raspberry Pi Pico and W55RP20 EVB Pico) to ensure the mode is switched and recognized correctly.

**If UART mode :**

| Raspberry Pi Pico | W55RP20 EVB Pico |
| --- | --- |
| GPIO4 (UART_TX) | GPIO5 (UART_RX) |
| GPIO5 (UART_RX) | GPIO4 (UART_TX) |
| GPIO13 (MODE_SEL) | GPIO13 (MODE_SEL) |
| GND | GND |

**If SPI mode :**

| Raspberry Pi Pico(Master) | W55RP20 EVB Pico(Slave) |
| --- | --- |
| GPIO2 (SPI_CLK) | GPIO2 (SPI_CLK) |
| GPIO3 (SPI_TX) | GPIO4 (SPI_RX) |
| GPIO4 (SPI_RX) | GPIO3 (SPI_TX) |
| GPIO5 (SPI_CS) | GPIO5 (SPI_CS) |
| GPIO26 (SPI_INT) | GPIO26 (SPI_INT) |
| GPIO13 (MODE_SEL) | GPIO13 (MODE_SEL) |
| GND | GND |

3. Connect the Raspberry Pi Pico to your PC (desktop or laptop) using a 5-pin Micro USB cable.

4. Connect the W55RP20 EVB Pico to your PC (desktop or laptop) using a USB Type-C cable.

## Step 3: Setup Example

- Raspberry Pi Pico (Master) : [Getting started with Raspberry Pi Pico (MicroPython)](https://www.raspberrypi.com/documentation/microcontrollers/micropython.html)

Please refer to the link below to install the MicroPython firmware on the Raspberry Pi Pico.

- **W55RP20 EVB Pico : **[Getting started with W55RP20 EVB Pico](https://docs.wiznet.io/Product/Chip/MCU/Pre-programmed-MCU/W55RP20-S2E/w55rp20-evb-pico-s2e)

Please refer to the link below for instructions on how to use the W55RP20 S2E.

## Step 4: Upload Code

- **Raspberry Pi Pico**

Open Thonny IDE and connect to the Raspberry Pi Pico. Upload the following driver and example files to the Pico's storage.

![](https://maker.wiznet.io/upload/ckeditor5/408384515%5F1769791777%2Epng)

*PICO's storage*

Required Files:

1. `w55rp20_s2e_uart.py` (Required for UART mode)

2. `w55rp20_s2e_spi.py` (Required for SPI mode)

Example Application Files (Choose one to test):

- `06_web_server.py`

Configuration: Before running an example, open the Python file you intend to use and modify the User Configuration section at the top.

```c
# 06_webserver.py
#
# Web server example (Supports both SPI and UART modes):
# - Configure the module as TCP server + DHCP
# - Listen on local port and serve HTTP responses
# Select mode by changing the MODE variable below.

import time

# -------------------------------------------------------------------------
# Configuration
# -------------------------------------------------------------------------
MODE = "spi"   # Set to "spi" or "uart"

# IP Configuration Mode
USE_DHCP = True  # True: DHCP (IM=1), False: Static IP (IM=0)

# Network Configuration
LOCAL_IP    = "192.168.11.100"  # Local IP (Used when USE_DHCP=False)
SUBNET_MASK = "255.255.255.0"   # Subnet Mask (Used when USE_DHCP=False)
GATEWAY     = "192.168.11.1"    # Gateway (Used when USE_DHCP=False)
DNS_SERVER  = "8.8.8.8"         # DNS Server (Used when USE_DHCP=False)

LOCAL_PORT = "80"  # HTTP port to listen on
.
.
```

- Note on Connection Status Check

Note: Real-time connection status verification using the `ST` (Status) command is recommended only for SPI mode. In UART mode, the module operates as a transparent data pipe. Sending AT commands (like `ST`) requires switching out of Data Mode using `+++`, which would interrupt the active Web Server connection. Therefore, this example relies on data polling for compatibility with both modes.

## Step 5: Run

![](https://maker.wiznet.io/upload/ckeditor5/617500408%5F1770398738%2Epng)

Pico (Thonny):

- Open `08_web_server.py`.

- Run the script (F5).

- If you used DHCP, check your Router's connected device list to find the "WIZnet" or "W55RP20" device IP.

- If you used Static IP, use the IP you defined (e.g., `192.168.11.100`).

- Wait for the "Server is listening..." message.

---

![](https://maker.wiznet.io/upload/ckeditor5/617500408%5F1770398809%2Epng)

Result:

- Type the IP address in the address bar: `http://192.168.11.100` (Replace with actual IP).

- The browser should display the "W55RP20-S2E Web Server" page.

- Thonny shell will show:![](https://maker.wiznet.io/upload/ckeditor5/617500408%5F1770398828%2Epng)

---

Source: https://maker.wiznet.io/Grace_Koo/projects/w55rp20-s2e-web-server-example-micropython/