In August 2014 from the Raspberry Pi foundation announced a new revision of the Raspberry Pi model B called a Raspberry Pi B+ which was a redesign of the old board with a new 40 pin GPIO connector, two extra USB ports and other changes on the board to improve the power consumption and changes to the memory card.
When we saw the announcement of the new design and that the Raspberry Pi model B was being discontinued we started work designing new versions of our most popular expansion boards to fit on the new Raspberry Pi B+ header and new mounting layout.
The Raspberry Pi foundation also released a new specification for non-stacking expansion boards which they are calling ‘HATs’ (Hardware Attached on Top). A Raspberry Pi HAT is a rectangular board (65x56mm) which has four mounting holes in the corners that align with the mounting holes on the B+, has a 40W GPIO header and an EEPROM which holds information about the HAT.
The full specification for the HAT is on https://github.com/raspberrypi/hats and an expansion board can only be called a HAT if it meets these specifications:
- It conforms to the basic add-on board requirements
- It has a valid ID EEPROM (including vendor info, GPIO map and valid device tree information).
- It has a full size 40W GPIO connector.
- It follows the HAT mechanical specification
- It uses a GPIO connector that spaces the HAT between 10mm and 12mm from the Pi (i.e. uses spacers between 10mm and 12mm).
- If back powering via the GPIO connector the HAT must be able to supply a minimum of 1.3A continuously to the Pi (but ability to supply 2A continuously recommended).
- HAT’s cannot be stacked on the Raspberry Pi (confirmed in forum posts from the moderators at the Raspberry Pi Foundation)
All of our previous Raspberry Pi expansion boards can be stacked to allow you to mix and match the inputs / outputs / expansion options you require so we would not be allowed to call our new Raspberry Pi B+ boards ‘HATs’ as they are stackable expansion boards.
We would also not be able to include the ID EEPROM as this would restrict our users to only using one expansion board at a time which we feel is very limiting based on customer’s feedback. Most of our customers use more than one of our current range of boards on their Raspberry Pi such as the real-time clock and extra IO ports or analogue inputs or outputs.
All of our new range of Raspberry Pi B+ expansion boards are stackable and we now offer a four pack of our mounting kits at a reduced price compared to buying a single mounting kit to allow you to securely attach the board to your Raspberry Pi B+.
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