Circuit & PCB Design for RPI (RPI Hat, or extension board)

Overview Motherboard type design that will allow either Model B Type Raspberry Pi or Model Zero Type Raspberry Pi to be mounted on to the motherboard using a common header set on the Motherboard. Board will be used to extend functionality of RPI devices for a specific set of requirements as detailed in this document. Some high-level details of functionality that this motherboard would deliver:  Power Regulation and power supply to RPI over GPIO  5vDC and 3.3vDC Power rails (for logic level circuitry)  Voltage and current monitoring at three different power points (Input, 5v, & 3.3v)  Some basic user interface through 4 Switches and 4 LEDs  Power Boost to a Type A USB socket  Audio Output via GPIO pins See associated Block Diagram (uploaded) for idea of component requirements. Ignore layout this is purely for spec up only. Notes:  More details will be provided after preliminary discussion  Board design, circuit design and component spec required  All components parts must be Digikey sourced  Guidance from board designer as to best spec and best practice on circuit design willingly accepted  This board design is part of an existing ongoing project, all software and coding will not be part of this scope but consideration must be given to RPI GPIO capabilities when specifying components  Expected Revisions - 2; so, three versions, first submission, revision one, revision two