--- title: "Look Inside the CloudFridge" url: "https://maker.wiznet.io/Sunny_/projects/look-inside-the-cloudfridge-1/" markdown_url: "https://maker.wiznet.io/Sunny_/projects/look-inside-the-cloudfridge-1/md" type: "UCC: User Created Content" author: "Sunny_" author_url: "https://maker.wiznet.io/Sunny_/" original_author: "SUNNY" original_url: "https://makezine.com/projects/look-inside-cloudfridge" published: "2026-01-16" language: "en" likes: 0 views: 287 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # Look Inside the CloudFridge > Look Inside the CloudFridge Original author: SUNNY (source: https://makezine.com/projects/look-inside-cloudfridge) ## Article ![클라우드프리지2](https://i0.wp.com/cdn.makezine.com/uploads/2013/10/cloudfridge2.jpg?resize=336%2C465&ssl=1) ## 📌 overview CloudFridge is a small IoT project that records **when, how often, and how long** a refrigerator door is opened, then sends that data to the cloud. With only: a magnetic **reed switch** on the fridge door, an **Arduino + WIZnet-based Ethernet shield (W5100/W5500)**, and a wired LAN connection, the system turns everyday fridge usage into **time-series data** that can be visualized and analyzed. Because the refrigerator is one of the biggest energy consumers in a home, this data helps you see where door-open behavior may be wasting energy and gives a concrete basis for behavior change. --- ## 📌 Key Functions ![](https://maker.wiznet.io/upload/ckeditor5/210237294%5F1768562548%2Epng) **![](https://maker.wiznet.io/upload/ckeditor5/210237294%5F1768562572%2Epng)Door state measurement** A reed switch detects door open/close events. For each reporting interval, the Arduino calculates: `openCount` – how many times the door was opened `openDuration` – total time the door stayed open **Cloud upload via HTTP** At fixed intervals (e.g., every 30 seconds), these values are sent as a simple HTTP PUT/POST to a server. Any HTTP-capable backend can be used: legacy Xively, modern services (ThingSpeak, InfluxDB, etc.), or a custom REST API. The result is a fridge “usage timeline” you can graph over hours, days, or months. ![](https://maker.wiznet.io/upload/ckeditor5/637864149%5F1768812068%2Epng) **Local visual status (RGB LED)** A small RGB LED (e.g., BlinkM) shows system state at a glance:normal operation,door currently open,network or upload error. **Power-use awareness** The design explicitly notes that the monitor itself consumes power (a few watts) and suggests reducing upload rate or using sleep modes when long-term logging is the goal. --- ## ![](https://maker.wiznet.io/upload/ckeditor5/210237294%5F1768562651%2Epng)📌 System Architecture **Sensor layer** A magnetic reed switch + magnet pair detects whether the door is open or closed. The Arduino tracks transitions and measures how long each opening lasts, then aggregates this into `openCount` and `openDuration` per interval. **Edge device: Arduino + WIZnet Ethernet** Arduino Uno (or similar) plus a W5100/W5500-class Ethernet shield. Responsibilities:Obtain IP configuration (typically via DHCP) Aggregate door events over time Periodically send an HTTP request with the latest metrics Drive the status LED **Cloud service** Receives the HTTP payload, stores it with timestamps, and exposes:dashboards/graphs for quick visualization, APIs for further analysis and integration,simple alert rules (e.g., “door open longer than N seconds”). --- ## 📌 W5100 / W5500 Role In CloudFridge, the WIZnet Ethernet controller is essentially the **wired gateway that puts the refrigerator on the internet**. **Wired Ethernet link** Stable and predictable latency via RJ45 and a home router. Better suited than Wi-Fi for small devices that log continuously, 24/7. **Hardwired TCP/IP stack** DHCP, ARP, TCP session management and retransmissions are handled inside the chip. The microcontroller just opens a socket, sends an HTTP string, and reads the response. **W5100 vs W5500 in this patternW5100** 4 sockets, 16 KB buffer Classic Arduino Ethernet Shield controller More than enough for one CloudFridge node uploading to a single cloud endpoint. **W5500** 8 sockets, 32 KB buffer, faster SPI Makes it easier to add:a built-in web configuration page,multiple upload targets (local server + cloud),additional monitored appliances on the same device. --- ## 📌 WIZnet Perspective ![](https://maker.wiznet.io/upload/ckeditor5/210237294%5F1768562984%2Epng) CloudFridge is a clear example of the pattern: > **Sensor → MCU → WIZnet Ethernet → HTTP → Cloud** applied to a refrigerator. The **local side** (Arduino + W5100/W5500) handles real-time sensing, aggregation, and upload timing. The **cloud side** provides long-term storage, visualization, and alerting. This pattern generalizes naturally to other cold-chain and appliance scenarios—freezers, display fridges, lab refrigerators—where door activity matters. In all of these, a WIZnet Ethernet chip can act as the simple, reliable, always-on network bridge between very small hardware and internet-scale data and services. --- ## 📌 Short Summary CloudFridge uses a reed switch, an Arduino, and a WIZnet Ethernet controller to measure refrigerator door openings and send the results to the cloud over HTTP. It’s a compact reference design for:**door-event–based energy and habit tracking on refrigerators**, and**small wired-Ethernet IoT nodes** that rely on WIZnet’s hardwired TCP/IP to stay simple, reliable, and always connected. --- Source: https://maker.wiznet.io/Sunny_/projects/look-inside-the-cloudfridge-1/