#hataday is BACK! RGB Matrix + Real Time Clock HAT @Raspberry_Pi #raspberrypi
First up, an RGB Matrix + Real Time Clock HAT – for our RGB Matrix displays. I went all out with this one, adding 5V power protection, 3->5V level shifting and a real time clock! See all the upcoming hats and more, RIGHT HERE!
In a nutshell a HAT is a rectangular board (65x56mm) that has four mounting holes in the (nicely rounded) corners that align with the mounting holes on the B+, has a 40W GPIO header and supports the special autoconfiguration system that allows automatic GPIO setup and driver setup. The automatic configuration is achieved using 2 dedicated pins (ID_SD and ID_SC) on the 40W B+ GPIO header that are reserved for an I2C EEPROM. The EEPROM holds the board manufacturer information, GPIO setup and a thing called a ‘device tree‘ fragment – basically a description of the attached hardware that allows Linux to automatically load the required drivers.