Understanding the Raspberry Pi HAT
The Raspberry Pi in its various iterations has
brought powerful computing to a compact format, and has transformed
what we thing possible from microcomputing. But as with any design, the Raspberry Pi is a compromise, it cannot
include every feature someone may want to use. That is where the Pi Hat comes in, allowing developers to quickly add
improved connectivity or other features without adding to the overall footprint of the Pi.
The Pi Hat sits directly on top of the Pi itself, using a specific set of standards and dimensions as laid out by
the Raspberry Pi foundation to ensure complete compatibility. You can
stack multiple Pi Hats to add all the features
you need to a project. Hats come in many
forms and can add almost any functionality you can think of, all with he
same easy plug and play operation for easy expansion of your Pi system.
Types of Pi Hat
While all Pi Hats follow the same format for compatibility, they vary significantly in what they can do. Raspberry
Pi Hats are purposely designed to accomplish specific things, but all fall into one of these types:
Sensor Hats — These Pi Hats feature sensors of various kinds onboard to allow the Pi to monitor
a number of environmental variables, including temperature, humidity, air quality and so on
Communication Hats — Add connectivity options to the Pi, this could be Wi-Fi, Bluetooth or
Cellular, and often a combination of those
Multimedia Hats — These Pi Hats add the ability to drive a screen or create audio output for a
variety of uses
Automotive Hats — These hats are designed for specific automotive applications, with the most
common being:
DOIP
HAT — Enables diagnosis over IP for remote vehicle management services
Key fob
Hat — With this hat the Raspberry Pi can communicate directly with the
vehicle’s key fob, allowing the system to control locking and unlocking and features such as remote
starting
With these Pi Hats, developers can add almost any feature to a project, allowing the Raspberry Pi to reach far
beyond its original capabilities and set new boundaries for innovation.
Installing a PI Hat
Perhaps the best part of the Raspberry Pi design is that hats are so easy to install there is no barrier at all to
getting the most out of them. They do require physically mounting to the Pi in most cases, but the standardized
design makes this a simple process.
To illustrate this, here is how you install the AutoPi TMU
CM4 . With the Pi powered off before you begin, just
follow these steps:
Attach the Hat — All hats feature a GPIO
connector along either side on the bottom of the
board, designed to align with the corresponding Pins in the Pi Board itself. Carefully line the pins and
sockets, and press gently, the pins will slide in and that is it, your Hat is physically installed
Install your Software — Because Pi Hats add additional functionality, they usually require some
software to get them working, and our AutoPi TMU CM4 is no different. Just download the software and follow
the instructions, it’s all very straightforward
Using the Pi Hat — Once the software is up and running, just follow the instructions for your
specific Pi Hat to get the most out of it
Conclusion
The raspberry Pi has been a remarkable driver of innovation, and the Pi Hat concept has been central to that. The
ability to quickly add new functionality, and for developers to create custom hats for specific needs, have meant
that the Raspberry Pi reaches far beyond its initial spec sheet to become a truly flexible source of computing power
for any industry.
The way Hats only increase vertical height without impacting footprint makes them especially useful in space
constrained applications, and whether it is for hobbyists or commercial projects across almost every industry, the
combination of Raspberry Pi and the Pi Hat has proven to be a unique, powerful and flexible system that continues to
push the boundaries of microcomputing.