PiSquare enables wireless Raspberry Pi HAT control though ESP8266 and RP2040 MCUs (Crowdfunding)

SB Components PiSquare is a board following the Raspberry Pi HAT form factor, and based on Raspberry Pi RP2040 microcontroller & ESP-12E Wireless module in order to control multiple Raspberry Pi HATs wirelessly without stacking them on their Raspberry Pi.

The PiSquare uses Socket programming to control multiple Raspberry Pi HATs wirelessly, and for instance, you could connect multiple HATs with SPI or UART without the expansion boards conflicting with each other since the physical interface is handled by the Raspberry Pi RP2040 on each PiSquare connected over WiFi (ESP8266) to the Raspberry Pi SBC.

PiSquare Wireless Raspberry Pi HAT RP2040 & ESP8266

PiSquare hardware specifications:

  • MCU – Raspberry Pi RP2040 dual-core Cortex-M0+ microcontroller @ up to 133 MHz
  • Storage – 16Mbit SPI flash
  • Display – 0.91-inch OLED display
  • Connectivity – 802.11b/g/n WiFi 4 via ESP-12 (ESP8266) module
  • USB – 1x USB Type-C port
  • 40-pin header and form factor compatible with the official Raspberry Pi HATs
  • Power Supply – 5V via USB Type-C port
  • Dimensions – 85 x 54 mm (Raspberry Pi HAT form factor)

PiSquare Wireless HATs connection

The solution basically allows you to connect as many Raspberry Pi HATs as you’d like to a single Raspberry Pi SBC with the limit being the number of WiFi clients that can be handled by your router. The “project page” on Hackster.io sadly lacks information about the software and we are only told that the PiSquare can be controlled through a smartphone and socket programming.


SB Components PiSquare is available for 9 GBP (almost $12) on Kickstarter, and the retail price will be 14 GBP or around $18.4 US. Shipping is scheduled for June 2022 and adds 5 GBP to the UK, about $13 to the US, and close to $20 to the rest of the world.

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Stefan Brüns
Stefan Brüns
2 years ago

I think the most interesting use case is connecting Hats to all kinds of computers. They list (Android?) phones on their page, but obviously this should also work for Laptops and Desktop PCs.
Interesting question would be how they abstract accessing the buses.

Stefan Brüns
Stefan Brüns
2 years ago

I was referring to the “host” side of the communication. There are several, likely non-exclusive options for those:

  • Create kernel-level bus controllers, mimicking spidev/i2cdev interfaces
  • Emulate e.g. spidev/i2cdev in userspace with CUSE
  • Extend popular libraries, i.e. all those Python GPIO access libraries

There is also stuff that definitely won’t work

  • Bit-banging i2c on generic GPIO pins
  • Latency critical GPIO interrupts
  • (Likely) I2S

On the other hand, there is probably some stuff that could leverage the extra capabilities the RP2040 has.

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