This presentation will provide guidelines how to create an open sourcehardware add-on board for the most popular single board computer Raspberry Piusing free and open source tools from scratch. Specifications of Raspberry PiFoundation for HAT (Hardware Attached on Top) will be revealed in details.Leon Anavi has been developing an open source Raspberry Pi HAT for IoT formore than a year and now he will share his experience, including the commonmistakes for a software engineer getting involved in hardware design andmanufacturing. The presentation is appropriate for anyone interested inbuilding entirely open source products that feature open source hardware andopen source software. No previous experience or hardware knowledge isrequired. The main audience are developers, hobbyists, makers, and students.Hopefully the presentation will encourage them to grab a soldering iron andstart prototyping their DIY open source device. Raspberry Pi is the most popular single board computer among hobbyists andstudents. In 2014 Raspberry Pi Foundation released a specification for add-onboards called HAT (Hardware Attached on Top). Nowadays we are capable ofmaking our own open source add boards following these specifications. In thispresentation, Leon Anavi will share his experience in designing an open sourcehardware Raspberry Pi HAT and developing open source software for it usingonly free and open source tools such as KiCAD. Leon has been working on hisRaspberry Pi HAT as a hobby project in his spare time for more than a year. InNovember 2016 his open source Raspberry Pi was successfully crowdfundedthrough IndieGoGo. Now he will explain the challenges and the common mistakesfor a software engineer getting involved in hardware design and manufacturing.The presentation will reveal details about the technical specifications ofRaspberry Pi HAT, the life cycle of entirely open source project and willprovide getting started guidelines. The presentation is appropriate for anyoneinterested in open source hardware and open source software development.Previous experience or knowledge about hardware design is NOT required.Attendees can expect details about Raspberry Pi HAT technical specification,embedded Linux software development tips for Raspberry Pi, guidelines forhardware design and low cost manufacturing of prototypes or small volume PCB.This presentation will help software developers, hobbyists and students betterunderstand the value of open source hardware and hopefully it will encouragethem to a get a soldering iron and start prototyping add-on boards for theirfavorite Raspberry Pi. The presentation will be also useful to peopleinterested in the concept of entirely open source projects that integrate opensource hardware and software created with free and open source tools.