Raspberry Pi's HAT+ Spec and PCIe FFC Connector: New Add-On Standards and SSD Options
The Raspberry Pi project has released the first revision to its Hardware Attached on Top (HAT) spec, introducing the HAT+ spec with four main changes. The HAT+ boards must be electrically compatible with the STANDBY power state, the specification is less prescriptive about physical dimensions, the HAT EEPROM content is simplified, and a special class of HAT+s that can be stacked with an extra HAT+ on top is supported. The release also addresses the omission of an M.2 connector from the RPi 5, but the Pi team has found a way to connect it using the PCIe connector. A forthcoming M.2 HAT+ is in the final stage of prototyping and will be launched early next year.