---
title: "UARDECS W55RP20 envsensor"
url: "https://maker.wiznet.io/Aimee0/projects/uardecs-w55rp20-envsensor/"
markdown_url: "https://maker.wiznet.io/Aimee0/projects/uardecs-w55rp20-envsensor/md"
type: "UCC: User Created Content"
author: "Aimee"
author_url: "https://maker.wiznet.io/Aimee0/"
original_author: "aimee"
original_url: "https://github.com/shinrinakamura/uardecs-w55rp20-envsensor/tree/95a8aa0deb07f294bbb6a82b1a9dd945f0bbe9d4"
published: "2025-07-21"
language: "en"
hardware: ["WIZnet W55RP20"]
likes: 0
views: 1080
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# UARDECS W55RP20 envsensor

> An environmental sensor device implementing the UECS (formerly UARDECS) protocol on the W55RP20-EVB-PICO board

Original author: aimee (source: https://github.com/shinrinakamura/uardecs-w55rp20-envsensor/tree/95a8aa0deb07f294bbb6a82b1a9dd945f0bbe9d4)

## Components

- **WIZnet W55RP20** x 1 ([docs](https://wiznet.io/products/ionic-chips/w55rp20))

## Article

## 🌿 UARDECS on W55RP20-EVB-PICO: Ethernet-Ready UECS Sensor Node

This project showcases a practical port of **UARDECS**, a UECS (Universal Environmental Control System) communication library originally developed for Arduino UNO/Mega, to the **W55RP20-EVB-PICO** platform (RP2040 + W5500 SiP). The result is a high-performance, Ethernet-native environmental sensor demo node optimized for smart farming and greenhouse control.

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### 🔧 Key Features

**No Ethernet Shield Required**: Built-in W5500 with native Ethernet (10/100M PHY) and hardware TCP/IP stack—no need for external shields.

**Full UECS CCM Support**: Reliable communication using Japan's standard protocol for environmental control.

**Browser-based Configuration**: Easily configure node settings via a built-in web UI served from the device itself.

**Embedded Optimizations**:

MAC address auto-generation using RP2040’s unique ID

Flash-based pseudo-EEPROM for configuration persistence

Safe-Mode booting via GPIO14 grounding

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### 🧱 Hardware Stack

| Component | Role | Notes |
| --- | --- | --- |
| **W55RP20-EVB-PICO** | MCU (RP2040, dual-core @133 MHz) + W5500 | AWS IoT qualified, on-board 10/100M PHY |
| **I²C Environmental Sensors** | Temperature, Humidity, CO₂, Light etc. | GP4/GP5 as I²C default pins (customizable) |

> 📌 **Sensor models are not fixed—please refer to the README or schematics for actual sensor choices.**

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### 💻 Software Stack

| Layer | Library / Technology | Highlights |
| --- | --- | --- |
| Network | `lwIP` + `EthernetCompat` | Compatible with Arduino Ethernet API while leveraging `lwIP` |
| Application | `UARDECS` | Implements UECS CCM for sensor data exchange |
| Utilities | Web UI, Safe Mode, Flash Config | Field-friendly design for configuration & maintenance |

---

### 🔍 Key Implementation Differences

| Feature | Arduino UNO/Mega Version | W55RP20 Port (This Project) | Benefits |
| --- | --- | --- | --- |
| Ethernet Driver | External W5500 SPI Shield | On-chip W5500 + `lwIP` | Reduced BOM & area, faster throughput |
| MAC Address | Hard-coded | Generated from `pico/unique_id` | Eliminates address collision |
| Buffer Size | 500 bytes | 1024 bytes | Improves logging & large packet handling |
| Config Storage | EEPROM | Flash-based pseudo EEPROM | RP2040-friendly persistent storage |

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### ✅ Strengths & Areas for Improvement

**Strengths**:

**Wired LAN reliability**: Ideal for greenhouses with Wi-Fi interference concerns

**UECS compatibility + Web UI**: Interoperability and convenience for non-engineers

**Potential Enhancements**:

Add sensor schematics and assembly photos to README

Log and publish performance metrics: packet loss, power usage, web UI latency

Include Safe-Mode flowchart in documentation

Provide inter-node compatibility test results from real greenhouse deployments

---

Source: https://maker.wiznet.io/Aimee0/projects/uardecs-w55rp20-envsensor/