I Reviewed 5 Open-Source HALs — What They Got Right and Wrong
I’ve spent the last few years writing abstraction layers between hardware and application software. Part of my job is knowing what’s out there, what works, and what breaks when you need it most. So I went through five open-source hardware abstraction layers and evaluated them on the criteria that matter for production firmware. Here’s what I found. The Evaluation Criteria I scored each HAL on five dimensions: Portability — How many MCU families does it support? How hard is it to add a new one? Performance — What’s the overhead vs direct register access? API Design — Is the API intuitive? Consistent? Does it leak hardware details? Documentation — Can a new developer figure it out without reading the source? Production Readiness — Is it used in real products? Are there gotchas? Scale: 1 (poor) to 5 (excellent). ...