What is a Raspberry Pi HAT?

dacplus-rca-raspberry-600x600The new HiFiBerry DAC+ and Digi+ come as Raspberry Pi HATs. What does this mean for you and why should you use a HAT?

HAT stands for “Hardware attached on top”. It is a new hardware specification for add-one modules for the new Raspberry Pi model B+. HATs have several advantages compared to older add-on modules for the Raspberry Pi.

  • No soldering, just plug it onto the Raspbery Pi
    With our older HiFiBerry boards you had to solder an 8-pin header onto the Raspberry Pi. While this is not a problem for experienced hackers, not everybody owns a solder station and can do this.
  • Robust mechanical design
    With 4 mounting holes the connection between the Raspberry Pi and the add-on board is very robust. We think, 4 connections is already overkill, 2 will usually do the job.
  • Auto-configuration
    This is a feature we like a lot. With an EEPROM module on the board, the add-on board identifies itself. It tells the Raspberry Pi, which IO pins it is using, how they need to be configured and what drivers has to be loaded. Today, this is still not implemented, but the engineers of the Raspberry Pi foundation are already working on this. When the final software is released you can just plug the HAT module onto the Raspberry Pi and everything else will be configured automatically.
    Note that our boards supports this feature. However as the final specification is still not released, you might need to upgrade your board. This does not need any hardware changes. You will just download a small script, run it and press the button on the HiFiBerry board – that’s it.
Posted by Daniel on August 14, 2014