Usage

$ rake -T # see all tasks
$ rake # build the project, flash to the arduino
$ rake clobber # clean the project
$ rake SERIAL_PORT=/dev/ttyS99999 # use a different serial port
$ rake target:backup[backup.hex] # dump the flash from the target into backup.hex
$ rake target:preprocess # build a preprocessed version of the C files

Board Resources

• ATMega328P datasheet - http://www.atmel.com/dyn/resources/prod_documents/doc8161.pdf
• Arduino UNO Schematic - http://arduino.cc/en/uploads/Main/arduino-uno-schematic.pdf

Getting Started

The following are instructions for getting up and running under different operating systems. This will take you through installing avr-gcc, avr-libc, avrdude, and the AVR GNU Binutils.

Windows

First, install a recent version of Ruby. You can grab a Windows installer for Ruby from the RubyInstaller for Windows page. After installing Ruby, you'll need to open a console and use the gem command to install the Cucumber and

Second, you'll need a copy of WinAVR. Download the latest version and install it. You will want to make sure the option to 'Add directories to PATH' is checked.

WinAVR contains all the tools you need to use this scaffolding including (but not limited to):

• AVR GNU Binutils
• AVR GNU Compiler Collection (GCC)
• AVRDUDE
• avr-libc

In order to complete the next step, you'll need to download the Arduino software package this can be found on the Arduino download page.

After you've installed Ruby and WinAVR, connect the Arduino UNO to your Windows computer via the USB cable. It will attempt to install a driver, but will fail. Follow the instructions on arduino.cc to complete the installation of the drivers.

OSX

I recommend installing the needed AVR tools by means of Homebrew. If you're already setup with homebrew, then you should just have to execute the following commands. If not, take a moment to read a bit about Homebrew and get it setup on your Mac.

Once you're ready, here are the commands to install the needed tools:

$ brew install avrdude
$ brew tap larsimmisch/avr
$ brew install avr-binutils
$ brew install avr-gcc
$ brew install avr-libc

These are built from source and will take a while to complete.

Linux

Getting the environment up and running on Ubuntu Linux is quite simple. One need only install 4 packages. These are all supported in the Ubuntu package manager. Open a terminal and run the following command:

$ sudo apt-get install binutils-avr avr-libc avrdude gcc-avr

Building and Running the Sample Project

The scaffold is driven by a Rakefile. If you're not familiar with Rake, you'll want to take some time to familiarize yourself with it. It's integral to the operation of this scaffolding.

The different stages of the build process are broken down into different rake tasks. These can be viewed by running the command rake -T in the scaffold directory. You'll see something like this:

$ rake -T
rake clean                       # Remove any temporary products.
rake clobber                     # Remove any generated file.
rake target:backup[backup_name]  # Make a backup hex image of the flash con...
rake target:build                # Build the project for the Arduino
rake target:convert              # Convert the output binary to a hex file ...
rake target:link                 # Link the built project for the Arduino
rake target:preprocess           # Generate the preprocessed source files
rake target:program              # Program the Arduino over the serial port.

The name of the serial port used by the Arduino UNO needs to be passed as an environment variable to the rake command. If you do not know how to identify the name of the serial port used by the Arduino UNO, consult with the section corresponding with your operating system under the 'Identifying the Name of the Arduino UNO Serial Port' later in this document.

Building the Scaffold

The scaffold can be built, linked, and flashed by running the following command:

rake SERIAL_PORT=[serial port name]

The following is an example of the output one can expect to see when running the rake command in a windows environment. In this example, the serial port is COM3. It may be different in your environment.

C:\Development\arduino_c_scaffold>rake SERIAL_PORT=COM3
avr-gcc -DTARGET -DF_CPU=16000000UL -mmcu=atmega328p -Iinclude/ -Wall -Os -c -o build/src/main.o src/main.c
avr-gcc -mmcu=atmega328p build/src/main.o -o scaffold.bin
avr-objcopy -O ihex -R .eeprom scaffold.bin scaffold.hex
avrdude -F -V -c arduino -p ATMEGA328P -P COM3 -b 115200 -U flash:w:scaffold.hex

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.02s

avrdude: Device signature = 0x1e950f
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "scaffold.hex"
avrdude: input file scaffold.hex auto detected as Intel Hex
avrdude: writing flash (304 bytes):

Writing | ################################################## | 100% 0.08s

avrdude: 304 bytes of flash written

avrdude: safemode: Fuses OK

avrdude done.  Thank you.

If the file at src/main.c hasn't been altered, you should notice that the yellow surface-mount LED on the Arduino UNO has begun to blink. It should be cycling on and off with durations of about 1 second.

Identifying the Name of the Arduino UNO Serial Port

Windows

TBD

OSX

TBD

Linux

TBD

Exploring the Source Code

TBD