AVR-colash: Build and Flash Script for AVR on Arduino Nano

This repository provides a simple Bash script to assemble, and flash AVR assembly files (specifically for atmega328p on the Arduino Nano) using tools such as avr-as, avr-ld, avr-objcopy, and avrdude. This repository also provides a if you wish to use make instead.

Table of Contents

• AVR-colash: Build and Flash Script for AVR on Arduino Nano
  • Using the Makefile
  • Prerequisites
  • Installation
    • Removing the script locally
  • Script Overview
    • Script Logic
  • How to Use
    • 1. Compile Only
    • 2. Compile and Flash to Microcontroller
    • 3. Clean Build Directory
  • Customisation
    • 1. Change the Target Microcontroller
    • 2. Change the Serial Port for Flashing
    • 3. Error Handling
  • License
  • Troubleshooting

Using the Makefile

If you prefer to use make for building and flashing AVR assembly files, I've provided a Makefile that automates the process. It supports compiling .s files, generating .hex files, and flashing them to the Arduino Nano.

To learn how to use the Makefile, check out the detailed guide.

Prerequisites

Before using this script, ensure you have the following installed and configured on your system:

1. AVR-GCC tools: Includes avr-as, avr-ld, avr-objcopy for assembling and linking your code.
2. AVRDUDE: A utility for flashing microcontroller chips via a programmer.

To install these tools on Debian-based distributions, you can run:

sudo apt-get install gcc build-essential
sudo apt-get install gcc-avr avr-libc
sudo apt-get install avrdude

This will also install gcc on your system.

Installation

To install this script please run, this will clone this repository to ~/Downloads/avr-colash:

bash <(curl -s https://raw.githubusercontent.com/BeedPro/avr-colash/main/install.sh)

If you don't want to install it locally on your system then you can clone this repository by:

git clone git@github.com:BeedPro/avr-colash.git

You can now just copy the script or/and Makefile to your project directories. Note that if you do copy it instead of installing this script locally, then you must do ./avr-colash to run the script.

To install it locally:

cd avr-colash
./install.sh

Removing the script locally

If you wish to remove the script then remove avr-colash in ~/.local/bin or run:

./uninstall.sh

which is found in this repository.

Script Overview

This script automates the following tasks:

• Compiling .s (assembly) files to AVR object files using avr-as.
• Linking object files into ELF format using avr-ld.
• Converting ELF to Intel HEX format using avr-objcopy.
• Optionally flashing the generated HEX file to an AVR microcontroller (e.g., Arduino Nano).
• Cleaning the build directory to remove intermediate and compiled files.

Script Logic

The script has three main actions:

1. compile: Assemble the .s file into an object file, link it into an ELF file, convert to HEX, and clean up intermediate files.
2. flash: Compile as above and flash the resulting HEX file to the microcontroller.
3. clean: Remove all build artifacts.

How to Use

1. Compile Only

To compile an AVR assembly file into a .hex file:

avr-colash compile <filename.s>

• <filename.s>: The AVR assembly file you want to compile. Make sure the file is in the same directory as the script or provide a relative path.

Example:

avr-colash compile blink.s

This will create the following files in the build/ directory:

• Object file: build/blink.o
• ELF file: build/blink.elf
• HEX file: build/blink.hex

2. Compile and Flash to Microcontroller

To compile and flash the generated .hex file to an Arduino Nano (or another AVR microcontroller):

avr-colash flash <filename.s>

Example:

avr-colash flash blink.s

This will:

• Compile the assembly file as explained above.
• Flash the resulting .hex file to the AVR microcontroller using avrdude.

Note: The script assumes your Arduino is connected to /dev/ttyUSB0. If you are using a different port, modify the DEVICE_PORT at the start of the script:

avrdude -C /etc/avrdude.conf -p $MCU -c arduino -P /dev/ttyUSB0 -D -U flash:w:"$BUILD_DIR/$BASENAME.hex":i

Replace /dev/ttyUSB0 with the correct serial port. You can find this using ls /dev/USB*

3. Clean Build Directory

To remove all files generated during the compilation process:

avr-colash clean

This will delete the build/ directory and all its contents.

Customisation

1. Change the Target Microcontroller

By default, the script is set up for the atmega328p microcontroller (used in Arduino Nano). If you're working with a different microcontroller, update the MCU variable at the top of the script:

MCU="atmega328p"

Change atmega328p to your target MCU model.

2. Change the Serial Port for Flashing

If your Arduino or AVR device is connected to a different serial port (e.g., /dev/ttyUSB1), update the DEVICE_PORT variable at the top of the script.

3. Error Handling

The script checks for errors during each stage (assembly, linking, HEX conversion, and flashing) and exits if an error is detected. If you encounter specific errors, check the output of the corresponding command (e.g., avr-as, avr-ld, avr-objcopy, or avrdude) for more details.

License

This script is open for modification and distribution under the MIT License. Feel free to customise it to suit your project needs.

Troubleshooting

• Device Not Found: If avrdude cannot find your device, make sure the correct port is specified and the device is properly connected.

Let me know if you need further assistance!

(P.S you can create an issue and I will help you with your problem)