This article is about creating a 7-segment display decoder in software. While this is probably considered a rather trivial task, it will serve as a good example for the discipline of Test-Driven Development (TDD). The motivation for a test-driven approach in this case is simple: being able to refactor later without the need to debug on hardware.

This post has moved to my new blog: [deardevices.com](https://deardevices.com/2017/12/17/test-driven-7-segment-decoder/)! [![Dear Devices](https://steffen.ronalter.de/assets/deardevices.png)](https://deardevices.com/2017/12/17/test-driven-7-segment-decoder/)