ATmega328P Data Logger PCB

A custom two-layer embedded data-logger PCB designed in KiCad around the ATmega328P microcontroller.

The board integrates external non-volatile memory, a real-time clock, user/status interfaces, and communication headers to provide a flexible hardware platform for data acquisition and logging applications.

Project Overview

The board was designed to combine the core hardware required for an embedded data-logging system on a single PCB.

Key functions include:

• ATmega328P microcontroller
• External EEPROM for non-volatile data storage
• Real-Time Clock for timestamping
• I2C, SPI, and UART communication interfaces
• MCU GPIO expansion headers
• Status LEDs and user input
• External power connection
• Manufacturing Gerber and drill outputs

Hardware Architecture

                   ┌─────────────────┐
                   │    ATmega328P   │
                   └───────┬─────────┘
                           │
          ┌────────────────┼────────────────┐
          │                │                │
          ▼                ▼                ▼
     External EEPROM    DS1337 RTC      I/O Expansion
          │                │         ┌──────┼──────┐
          │                │         │      │      │
         I2C              I2C       UART   SPI    GPIO

Main Components

ATmega328P

The ATmega328P acts as the main controller of the data-logger board and provides the processing and peripheral interfaces required by the system.

External EEPROM

The design includes two 24LC1025 EEPROM devices to provide additional non-volatile storage for logged data.

The EEPROM devices communicate with the MCU through the I2C interface.

DS1337 Real-Time Clock

A DS1337S I2C Real-Time Clock provides date/time information that can be used to timestamp logged data.

Communication Interfaces

Dedicated headers expose the MCU communication peripherals:

• I2C
• SPI
• UART

Additional headers expose MCU GPIO from Ports B, C, and D for sensor or peripheral expansion.

PCB Design

EDA Tool: KiCad PCB Layers: 2 Board Material: FR-4 Board Thickness: 1.6 mm

The design includes:

• Front and back copper routing
• Ground and power distribution
• Through-hole interface connectors
• SMD components
• Silkscreen component identification
• Mounting holes
• Gerber and drill manufacturing outputs

PCB Layout

3D View

Expansion Interfaces

The board exposes dedicated connectors for:

Interface	Purpose
I2C	Sensors and external I2C peripherals
SPI	SPI-based sensors/peripherals
UART	Serial communication and debugging
PORTB	MCU GPIO expansion
PORTC	MCU GPIO expansion
PORTD	MCU GPIO expansion

Repository Structure

ATmega328P-Data-Logger-PCB/
├── hardware/
│   ├── data-logger.kicad_pro
│   ├── data-logger.kicad_sch
│   ├── connectors.kicad_sch
│   └── data-logger.kicad_pcb
├── manufacturing/
│   ├── gerber/
│   └── drill/
├── images/
│   ├── layoyt.png
│   ├── pcb_3d_front.png
│   └── pcb-3d-back.png
├── docs/
│   └── data-logger-project.pdf
└── README.md

Design Outputs

The repository includes the KiCad source files together with Gerber and drill outputs required for PCB fabrication.

Skills Demonstrated

• Embedded hardware design
• Schematic capture
• PCB layout and routing
• ATmega328P system design
• I2C peripheral integration
• External EEPROM integration
• RTC integration
• UART/SPI/I2C interface breakout
• KiCad
• PCB manufacturing-file generation

Project Scope

This repository focuses on the hardware and PCB design of the data-logger platform.

The project was completed through:

• Schematic capture
• PCB layout and routing
• Gerber generation
• Drill-file generation

The board was not fabricated or physically validated.

Firmware for complete data-logging functionality is outside the scope of this repository.