During this week, we continued strengthening our understanding of electronics, approaching the topic in greater depth by working at the level of electronic design. The main objective was to develop a functional circuit using an EDA (Electronic Design Automation) tool, while also gaining a more solid understanding of electronic components and the design rules required to achieve a reliable PCB.
For this assignment, we designed a custom development board based on the ATtiny412 microcontroller. This board integrates several electronic components that allow multiple functionalities. The entire process was carried out using KiCad, an EDA software that enables schematic design and PCB layout generation.
The ATtiny412 is an 8-bit microcontroller based on the AVR architecture. It is designed for low-power and compact applications. It features 8 pins, 4 KB of Flash memory, 256 bytes of SRAM, and uses a UPDI interface for programming and debugging through a single pin.
To upload the program, we use the UPDI interface (pin 6) together with an Arduino Nano, as shown in the schematic.
We installed KiCad, an open-source EDA software with a simple installation process.
We downloaded the Fab Academy component library from the official repository and extracted it into a specific folder.
We added the symbol libraries through Preferences → Manage Symbol Libraries, linking the fab.kicad_sym file.
Similarly, we added footprint libraries through Preferences → Manage Footprint Libraries.
We created a new project and saved it in a designated folder.
We opened the schematic file (.sch) to begin the circuit design.
Using the “Place Symbols” tool, we accessed and selected components from the libraries.
We added all required components into the workspace.
All components used were from the Fab library.
We assigned labels to define connections between components.
We verified that each component had an assigned footprint.
Missing footprints were assigned manually from the library.
We updated the PCB layout to display components and connections.
We routed all connections following proper track widths and electronic design rules. The circuit includes LEDs on pins 4 and 5 to visualize outputs, a resistor on pin 6 for UPDI programming, and a power indicator LED.
We performed a DRC (Design Rule Check) to ensure the board has no errors and is ready for fabrication.
As a result, we successfully designed a functional PCB based on the ATtiny412 microcontroller. The circuit integrates output LEDs, a programming interface via UPDI, and a power indicator. The design passed all DRC validations, confirming that it is ready for manufacturing.
This assignment allowed us to develop a deeper understanding of electronic design workflows, from schematic creation to PCB layout. We reinforced our knowledge of components, libraries, and design rules, while gaining practical experience using KiCad. The process highlighted the importance of precision and verification in ensuring a functional and manufacturable electronic design.