# Design Reference ### Input Sibling Boards Design references for researching our 32u4-based input boards. Blogs, schematics, datasheets and CAD files * Julian Hartline's "Designing and Building an Arduino-Compatible PCB" - Accessed Jan. 13, 2018 [Link](http://blog.julianhartline.com/archives/64) * Adafruit Itsy 32u4 Board Schematic - Accessed Jan 13, 2018 [Link](https://learn.adafruit.com/assets/49818) * Adafruit ATMega32u4 Breakout Board Tutorial Download Page (includes Eagle PCB files) - Accessed Jan. 13, 2018 [Link](https://learn.adafruit.com/atmega32u4-breakout/design) * NumberOne's 32u4 uBBB schematic on Hackaday (micro/ultra Bare Bones Board) - Accessed Jan. 13, 2018 [Link](https://cdn.hackaday.io/images/7383101437163354862.png) * Microchip's complete datasheet for ATMega32u4 - Accessed Jan. 13, 2018 [Link](http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7766-8-bit-AVR-ATmega16U4-32U4_Datasheet.pdf) * Example of layout and capacitor use for ATMega8u2 on AVRFreaks [Link](http://www.avrfreaks.net/forum/capacitors-32u4) * Discussion on decoupling capacitors on Vcc pins of ATMega32u4 [Link](http://www.avrfreaks.net/forum/which-decoupling-caps-atmega32u4) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.clomads.com/concepts/origami/design-reference.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.