One of the things that makes Raspberry Pi’s small and inexpensive single-board computers interesting is the 40-pin connectors that makes it possible to connect expansion boards called HATs (which stands for Hardware Attached on Top). These can add features like sensors, displays, additional ports and other I/O options, and much more.
But most of the time you can only use one HAT at a time, since they require a physical connection to the Raspberry Pi and cover the computer completely. The makers of the new PiSquare have come up with a way to let you use multiple HATs at once: by making them wireless.
PiSquare is a small board that basically makes it possible to turn any HAT into a wireless add-on for a Raspberry Pi. Just plug the HAT into the 40-pin connector on the PiSquare board and instead of plugging that HAT into the Raspberry Pi itself, you can connect it over a WiFi network.
This makes it possible to connect multiple HATs simultaneously by using multiple PiSquare boards, which means you don’t need to jump through the same hoops necessary to physically stack HATs atop one another. It also makes it possible to connect two or more of the same HAT to a Raspberry Pi, something which isn’t otherwise available.
Eventually expected to sell for £20 (~$26) each, you can currently reserve a PiSquare for £9 (~$12) through a Kickstarter crowdfunding campaign. Production is expected to begin in May, after the campaign ends and if everything goes according to plan the PiSquare boards will begin shipping in June, 2022.
The PiSquare board itself features a Raspberry Pi RP2040 microcontroller and ESP-12E 802.11b/g/n (WiFi 4) controller plus a 0.91 inch OLED display, 16MB of flash, and a USB Type-C port.
It should be compatible with any Raspberry Pi device that supports WiFi. And you can use either a Raspberry Pi or the PiSquare board as a server, allowing you to do things like:
- Connect one or more PiSquare-connected HATs to a Raspberry Pi that’s acting as a server
- Connect one or more PiSquare-connected HATs to another PiSquare that’s acting as a server
- Use your phone or another device to control one or more PiSquare-connected HATs
You can do most of those things by connecting the PiSquare to the same wireless network as a Raspberry Pi or other devices like your smartphone. But you can also use a direct device-to-device connection by setting up a Raspberry Pi or PiSquare to act as a hotspot.
While there’s always some risk involved with crowdfunding projects, the PiSquare comes from developer Jyoti Singh, who has already run two other successful Kickstarter campaigns for Raspberry Pi-related gear.