AVR8Sharp is a .NET Standard library designed to emulate the AVR-8 architecture. It is a port of the avr8js library, originally developed in TypeScript.

This library enables the execution of precompiled AVR-8 firmware and provides a robust framework for simulating AVR-8 microcontrollers within .NET environments. It is versatile and can be integrated into various types of applications, including console-based tools and graphical user interface (GUI) applications.

This library, like the original version, requires the following components to be provided:

• Precompiled firmware: The firmware to be executed must be precompiled and supplied.
• Functional hardware simulation: You need to implement the functional simulation of any external hardware interfacing with the microcontroller.
• (Optional) Visual or audio representation: If desired, a visual or audio representation of the simulated hardware can be added for enhanced interaction.

graph LR
    A[Precompiled Firmware] --> B[AVR8Sharp]
    B <--> C[Glue Code]
    C <--> D[External Hardware Functionality Simulation]
    D <--> E[Simulation State Display for the User]

To install the library, you can use the NuGet package manager or the .NET CLI.

dotnet add package AVR8Sharp

or

Install-Package AVR8Sharp

The library is designed with ease of use in mind, leveraging the Builder pattern for intuitive configuration. Below is an example demonstrating how to create a new runner for the Arduino Uno (ATmega328p) board and load firmware from a HEX file.

using AVR8Sharp;

class Program
{
    static void Main(string[] args)
    {
        // Load the firmware from a HEX file
        var file = File.ReadAllBytes("Serial.hex");
        var hex = Encoding.UTF8.GetString (file);
        
        // Create the AVR runner 
        var runner = AvrBuilder.Create () 
            .SetSpeed (16_000_000) 
            .SetWorkUnitCycles (1_000) 
            .SetHex (hex) 
            .AddGpioPort (AvrIoPort.PortBConfig, out _) 
            .AddGpioPort (AvrIoPort.PortCConfig, out _) 
            .AddGpioPort (AvrIoPort.PortDConfig, out _) 
            .AddUsart (AvrUsart.Usart0Config, out var usart) 
            .AddTimer (AvrTimer.Timer0Config, out _) 
            .AddTimer (AvrTimer.Timer1Config, out _) 
            .AddTimer (AvrTimer.Timer2Config, out _) 
            .Build ();
        
        // Add a listener when a byte is transmitted 
        var builder = new StringBuilder (); 
        usart.OnByteTransmit = b => { 
            var c = (char)b; 
            builder.Append (c); 
            if (c != '\n') return; 
            // Print the serial output 
            Console.WriteLine ($"Serial Output: {builder.ToString ().Trim ()}"); 
            builder.Clear (); 
        };
        
        while (true)
        {
            runner.Execute();
        }
    }
}

The code snippet above illustrates how to create an AVR runner for the Arduino Uno. This runner is specifically designed to execute the following Arduino sketch:

// Green LED connected to LED_BUILTIN,
// Red LED connected to pin 12. Enjoy!

void setup() {
  Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  Serial.println(""AVR8Sharp is awesome!"");
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
}

As a port of the avr8js library, AVR8Sharp primarily focuses on simulating the ATmega328p microcontroller. However, thanks to its highly modular and configurable design, the library is capable of simulating a wide range of microcontrollers within the AVR-8 family, including the ATmega2560 and the ATtiny series.

The library is tested using the NUnit testing framework. To run the tests, you can use the following command:

dotnet test

The following features are planned for future releases:

• Support for TWI (I2C) Slave mode

Copyright (c) 2019-2023 Uri Shaked.

Copyright (c) 2025-present, Iván Montiel.

This project is licensed under the MIT License. For more information, please refer to the LICENSE file.