Stackable HATs from Sequent Microsystems
All Sequent Microsystems HATs are designed as stackable Raspberry Pi HATs, making it easy to expand functionality without sacrificing space. Each board comes with extra-long 20-pin GPIO connectors and 19mm brass spacers, ensuring stable stacking. Almost all of our HATs are engineered to support eight-layer stacking, and you can mix and match them in nearly any combination to build the exact solution you need.
Practical Limits of a Raspberry Pi Stack
While our hardware can support much more, in most real-world applications a Raspberry Pi stack with more than eight HATs rarely makes sense. All cards communicate with the Raspberry Pi exclusively via the I²C interface, leaving all GPIO pins available for other tasks. Although I²C does impose some speed limitations, this is seldom a concern in automation projects where processes are already happening in real time.
How Far Can Stackable Raspberry Pi HATs Go?
Since the I²C bus is a local protocol not intended for long-distance communication without buffering, the natural question is: how large can a stackable Raspberry Pi HATs configuration really be? To answer this, we ran an experiment by continuously stacking HATs on top of each other and monitoring performance.
Our Stress Test Results
The system remained stable all the way up to 31 cards, at which point we simply ran out of test samples. Every HAT worked flawlessly, with no communication errors. This experiment proved that a stack of stackable Raspberry Pi HATs can grow far beyond practical needs.
Conclusion
While most automation projects will never require such a high number of expansion boards, the test demonstrates the robustness and scalability of Sequent Microsystems’ design. Whether you need just a few HATs or an extensive stack, you can trust our stackable Raspberry Pi HATs to deliver reliable performance.
