If you’ve ever wondered how to add real, expandable storage to your microcontroller projects, the article CH32V003F4P6 – SD card with FatFS is a great place to start. It shows how to connect an SD card to the CH32V003F4P6 using SPI and the FatFs filesystem, turning even a small MCU into a powerful data-logging device.
In the guide, the author walks through the setup process, explains how FatFs lets you handle files just like on a computer, and shows how to work within the MCU’s memory limits. The example code makes it easy to mount the filesystem, read and write files, and get real data stored securely.
What makes this project special is how affordable and universal it is. Using SPI means you don’t need special hardware, almost any microcontroller supports it. With just a few wires and an SD card module, you can build a logger, a simple file-based interface, or even a standalone device that records data over time.
Expanding the idea
SD cards aren’t the only way to add storage. Many projects use small SPI flash chips to store data, configuration files, or firmware updates. They’re fast and compact, and some support Quad SPI for extra speed. If you only need to save small amounts of data, EEPROM or FRAM chips are great alternatives, especially when you need low power use and long write endurance.
You can also go bigger. Some microcontrollers support USB mass storage, allowing you to use a USB stick for data transfer or firmware updates. Others offer SDIO, a faster interface than SPI, ideal for large file writes like audio or camera data. And for networked projects, you can skip local storage entirely by saving logs or files directly to a server or the cloud.
Why it matters
Adding storage opens up new possibilities, from data logging and offline caching to configuration management and updates. The original Curious Scientist article is an excellent foundation for learning how to connect and use storage devices in your own projects. Once you understand the basics of SPI and file systems like FatFs, expanding to other storage types becomes simple.
At eBits, we love seeing makers, students, and businesses bring ideas like this to life. Whether you’re building a sensor logger, a teaching tool, or a prototype device, adding reliable storage is a small upgrade that can make a huge difference.
