ATmega8-USB Prototyping Board

 The ATmega8-USB project is a simple USB-based prototyping board designed for Atmel's AVR microcontrollers, specifically the ATmega8. It is ideal for developing and experimenting with AVR-based embedded systems and USB interfacing. The KiCAD 3D model attached provides a visual representation of the board's layout and components.

View on GitHub

Project Features

1. Microcontroller:
    The ATmega8 microcontroller serves as the core of the board. Its versatility and support for USB interfacing make it suitable for prototyping a wide range of projects.
2. USB Connectivity:
    The board includes built-in USB support, enabling seamless communication between the microcontroller and a host computer.

3. On-Board Components:

• Oscillator Circuit: For generating the system clock.
• Reset Button: To easily reset the microcontroller.
• LED Indicators: Provide visual feedback for power, status, and debugging.
• Voltage Regulators and Capacitors: Ensure stable power delivery to the components.

4. Programming and Debugging:

• The board supports in-circuit programming (ICP) via USB.
• It can be used with tools like AVRDUDE or the Arduino IDE (if flashed with appropriate bootloaders).

5. Compact Design:
The compact form factor and simple layout make it suitable for rapid prototyping and integration into various projects.

Potential Applications

1. USB Devices: 

Create custom USB peripherals like keyboards, mice, or USB HID devices.

2. Embedded Systems: 

Develop and test AVR-based embedded applications for IoT, robotics, and home automation.

3. Learning and Experimentation: 

Ideal for students and hobbyists to learn about microcontrollers, USB communication, and embedded system design.
4. Prototyping: Quickly develop proof-of-concept models for custom applications.

Steps to Build the ATmega8-USB Board

1. Prepare Components:

• ATmega8 microcontroller
• USB connector
• Oscillator (12 MHz recommended for USB applications)
• Capacitors, resistors, LEDs, and voltage regulators as per the schematic

2. Design and Manufacture PCB:

• Use the provided KiCAD design to manufacture the PCB.
• Ensure all traces and ground planes are correctly routed for USB compatibility.

3. Assemble Components:

• Solder all components onto the PCB.
• Pay attention to the orientation of polarized components like LEDs, capacitors, and ICs.

4. Upload Bootloader:

• Flash the ATmega8 with a USB-compatible bootloader like USBaspLoader or V-USB Bootloader.

5. Test and Debug:

• Connect the board to a computer via USB.
• Verify that the device is recognized.
• Test communication using serial terminal software or USB libraries.

Sample Code for Testing (Blink LED)

Here’s a simple example to test the board by blinking an LED:

Code (C - AVR GCC):

#include <avr/io.h>
#include <util/delay.h>

#define LED_PIN PB0

int main(void) {
    DDRB |= (1 << LED_PIN);  // Set LED pin as output
    while (1) {
        PORTB ^= (1 << LED_PIN);  // Toggle LED state
        _delay_ms(500);          // Delay for 500 ms
    }
    return 0;
}

Future Enhancements

1. Expand Functionality: 

Add support for more peripherals like SPI, I2C, or UART.

2. Software Libraries: 

Develop libraries for easier USB communication using the V-USB library.

3. Integration: 

Create a companion software interface for testing and configuration.
4. Cross-Compatibility: Adapt the board for other AVR microcontrollers like ATmega328 or ATmega32.

This project combines the power of ATmega8 with USB functionality, making it an excellent tool for learning, prototyping, and developing embedded solutions. Let me know if you’d like to dive deeper into the firmware, PCB design, or software interface!