Overview
CardanoThings is a teaching site that shows you how to build small internet-connected gadgets that read from and write to a blockchain. The workshops are aimed mostly at beginners and are meant to be done in order1. They take you from setting up a test wallet to a QR-code payment terminal, and no prior Cardano experience is needed2.
The site is built around Cardano and ESP32 boards, which are microcontrollers: tiny computers that run one program and can join Wi-Fi. You write and upload the code with the Arduino IDE, the desktop program hobbyists use to program these boards2. Developer Dirk M. Kraft built CardanoThings with a grant from Fund 11 of Project Catalyst, Cardano's community funding program3. The Cardano Developer Portal reuses the workshops in its Internet of Things (IoT) course and names cardanothings.io as the main web version2.
Key Features
- A step-by-step path to your first device. CardanoThings offers five workshops that cover reading blockchain data, connecting screens and lights, recording sensor data on chain, building a price ticker, and taking payments4.
- Gadgets that react to the blockchain. One CardanoThings project switches a lamp on and off through a relay, an electrically controlled switch, based on events on chain. Another lights a ring of 12 LEDs to show how far the current epoch, a fixed stretch of time on Cardano, has progressed5.
- Sensor readings saved on chain. Workshop 03 reads a temperature sensor, then passes the readings to a small self-built server that records them on Cardano as NFTs, unique digital tokens6.
- Code you can run straight away. The board code for each workshop comes as an Arduino sketch, the name for a program on these boards, ready to open in the Arduino IDE. You add your Wi-Fi details and upload it to the board7.
- Short reference snippets. The Building Blocks section collects single-topic code examples, such as joining Wi-Fi or making a web request, that you can filter by board and topic8.
What to Expect
For beginners, CardanoThings teaches basic electronics and Cardano side by side. Workshop 01 has you install a wallet such as Yoroi on the Preprod testnet, a practice version of Cardano where test ADA has no real value. You then connect your board to your computer and Wi-Fi, make it blink, and fetch your first piece of blockchain data from an online service9. The workshops aim to use free services to keep costs low, and they point out paid tools you might use later for a real product10.
Before you start, the Hardware List explains each board and part used in the examples, where to get it, and how to set it up1. Most workshops use the Cheap Yellow Display, an ESP32 board with a built-in screen; an ESP32-C3 with a small add-on screen also works2. Short Introductions give background on topics such as Cardano and Arduino9, and a Glossary defines the terms used across the site1.
More experienced developers can use the snippets as a quick reference. The final workshop turns the board into a payment terminal that shows a QR code for mobile wallets like Yoroi, Vespr, or Begin to scan4. Those codes follow CIP-13, a standard format for Cardano payment links. A companion site, cip13.cardanothings.io, explains the link types and tracks which wallets support them11. The code examples, plus the website itself, sit in the project's public GitHub repositories1.
