One obstacle that newcomers to Raspberry Pi physical computing come up against is trying to figure out which pin does what on the Pi’s GPIO header, particularly since they’re not labelled. Previous solutions have included printing out a GPIO pin reference guide on such items as rulers and key-rings. Alternatively, users could just refer to an online diagram, such as at pinout.xyz. Even then, you still need to count down the two lines of pins on the Pi to locate the one required, which increases the chance of a potentially damaging wiring mistake.
The full article can be found in The MagPi 47 and was written by Phil King
Enter the RasPiO Pro HAT. Designed by Alex Eames of RasPi.TV, it makes using the GPIO pins a whole lot easier. Around the edges of its built-in breadboard are female header sockets connected to the Pi’s GPIO pins, arranged and labelled in numerical (BCM) order. So, for instance, if you want to hook up a component to GPIO 18, you simply plug its jumper wire into that labelled socket: no more pin-counting! Nor is any extra software required. The HAT works perfectly with GPIO Zero, as well as other libraries. It’s such as simple solution, it’s a wonder no one’s thought of it before.
The third female header comprises six extra connections apiece for 3V3 and GND; this comes in handy, since the mini 72-point breadboard doesn’t feature the ‘+’ and ‘–’power rails of larger versions. In addition, you won’t need quite so many jumper wires to power/ground all your components as they are, in effect, wired straight to the relevant GPIO pins. You may need to stock up on a few more male-to-male cables, though.
The other big advantage of the RasPiO is that it makes prototyping a lot safer, since a protection circuit with a 330Ω resistor and 3V3 Zener diode is built into each GPIO port. This means that you can use LEDs without extra resistors, and you won’t damage your Pi’s GPIO by wiring something up incorrectly, although you still need to take care not to directly short 3V3 or 5V power to GND! One side effect of this protection circuitry is that some components requiring more than the 10mA limit, such as buzzers, may be underpowered; fortunately, a line of unprotected through-hole ports is included for this purpose.
The RasPiO Pro HAT really does make electronics easier, eliminating the need for counting GPIO pins while also protecting them against incorrect wiring. About the only drawback is a lack of room on its half-size breadboard, but if you do need extra space for components, you could easily hook it up to another breadboard.