SERVO PI HAT! … a @Raspberry_Pi HAT we sent off for prototype PCBs for testing #hataday

August 16, 2014 adafruit

Say hello to the SERVO PI HAT. It’s part of a new feature we are doing here each day called “HAT A DAY” (sounds like hack-a-day, the site Phil started almost 10 years ago and ladyada is now a judge for in the SPACE contest! This is a HAT a day for a few weeks!)… This is a Raspberry Pi HAT we sent off for prototype PCBs for testing, we’ve sent off many, we’ll post a new HAT A DAY, so stop back soon and see the HATs live on ASK AN ENGINEER each week if we have time during IT’S NOT OUT YET. See all the HATS here!

Adafruit 3467
What’s a PI HAT? Glad you asked!


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.

Read more & spec here.