# Developing for the ATmega328P under Linux

1. Introduction
2. Compiling binutils
3. Compiling avr-gcc
4. Compiling avr-libc
5. Compiling AVRDUDE

## 1. Introduction

The Atmel AVR ATmega328P is the latest in the mega48/mega88/mega168 series of microcontrollers, which are used on the Orangutan Robot Controllers, Arduino boards, and in many other robot controllers and individual electronics projects. The mega328 has twice as much program (Flash) memory, RAM, and EEPROM as the mega168, while keeping the same architecture and pinout as the earlier chips. This means that most projects based on the earlier processors can be easily upgraded to the 328, making it possible to fit more complex programs or deal with more much more data.

### GCC support for the mega328P

The following systems have compiler support for the ATmega328 included:

• Microsoft Windows with AVR Studio and WinAVR (so Windows users should be okay after upgrading to the latest version of WinAVR).
• Ubuntu Linux versions 8.10 (intrepid) and up.
• Fedora 9 updates / Fedora Development
• Debian Linux 5.0.0 (lenny) and up.

Ubuntu 8.04LTS (hardy) does not currently offer a recent enough version of gcc to compile programs for the mega328, but future upgrades might provide support.

If you are using one if the systems with 328P support, just make sure that you have updated your system to use the latest version of WinAVR/avr-gcc. Otherwise, to install the latest version of the compiler and related tools, proceed to Section 3 and follow the step-by-step instructions.

### AVRDUDE support for the mega328P

The popular AVR programming software AVRDUDE includes support for the mega328 in version 5.6 and up. Since this was released on 27 February 2009, it is not included in the latest WinAVR distribution. Windows users will need to modify their avrdude.conf file as described at the end of Section 5.

## 2. Compiling binutils

### Checking the currently installed version of avr binutils

Run the following command:

avr-as  --version

After installing the latest avr-gcc, you should get the latest version of binutils. We tested these instructions with version 2.19.1.

### Unpacking the archive

Run the following command:

tar xzf ~/Desktop/binutils-2.19.1.tar.gz
cd binutils-2.19.1

### Configuring and compiling binutils

The options give here just specify that the AVR version of binutils should be compiled:

./configure --prefix=/usr/local --target=avr
make
sudo make install

### Next steps

You should now have the latest version of all of the binutils utilities compiled for the avr and installed in your /usr/local/bin. Proceed to Section 4 to install avr-libc for all of the AVR microcontrollers supported by gcc.

## 3. Compiling avr-gcc

The latest versions of GCC (4.2.3 and up) include support for the ATmega328P, as well as the ATmega48P, ATmega88P, and ATmega168P.

### Checking the currently installed version of avr-gcc

Run the following command:

avr-gcc --version

You can test for support by creating an empty file test.c and running avr-gcc -mmcu=atmega328p test.c. If your version of gcc does not support the chip, you will see the following errors:

unknown MCU 'atmega328p' specified
...
test.c:1: error: MCU "atmega328p" supported for assembler only

### Installing prerequisites

Recent versions of GCC (4.3.x) depend on GMP and MPFR, which can be installed from their web pages. Under Ubuntu, you can get these packages by running the following command.

sudo apt-get install libgmp3-dev libmpfr-dev

Other distributions probably provide similar packages.

Get gcc-4.3.3.tar.bz2 or a later version from the GCC FTP site or from a mirror closer to you if possible. We recommend getting the full GCC, which includes the C++ compiler, not just gcc-core.

### Unpack the archive

Run the following command:

tar xjf ~/Desktop/gcc-4.3.3.tar.bz2
cd gcc-4.3.3

### Configure, compile, and install GCC

Note that you need to compile GCC from a separate directory, and that we are specifying that only C and C++ be included. If you want to try compiling FORTRAN, ObjectiveC, or GCJ for the AVR, you’re on your own!

mkdir obj
cd obj
../configure --prefix=/usr/local --target=avr --enable-languages=c,c++ --disable-nls --disable-libssp
make
sudo make install

### Next steps

The latest version of avr-gcc should now be on your path. Next, proceed to Section 2 to install the latest binutils.

## 4. Compiling avr-libc

Get the latest version from the avr-libc website. You should get version 1.6.6 or higher.

### Configuring and compiling avr-libc

Run the following command:

tar xjf ~/Desktop/avr-libc-1.6.6.tar.bz2
cd avr-libc-1.6.6

### Compiling avr-libc

Make sure that the latest avr-gcc is on your path as the default avr-gcc before you run these commands, or you will not get support for the the mega328. When running configure, you should see a line of output that says (make sure “checking if avr-gcc has support for atmega328p… yes”. If you don’t see this, double-check your avr-gcc installation.

./configure --host=avr --prefix=/usr/local
make
sudo make install

### Next steps

You should now have an avr-libc installed that includes support for the mega328, so you will be able to compile programs for this microcontroller. To program a chip, you will probably want AVRDUDE. Section 5 contains instructions for compiling installing and installing the latest version.

## 5. Compiling AVRDUDE

### Checking the currently installed version of AVRDUDE

Run the following command:

avrdude -v

You need at least version 5.6 for ATmega328P support.

### Unpacking the archive

Run the following command:

tar xzf ~/Desktop/avrdude-5.6.tar.gz
cd avrdude-5.6

### Compiling and installing AVRDUDE

Unlike the other packages, AVRDUDE does not need to be specifically told to compile for the AVR. So you should be able to compile it with no special options:

./configure
make
sudo make install

### Optional: configuring earlier versions of AVRDUDE for the ATmega328P

The following configuration file will let versions of AVRDUDE before 5.6 work with the 328. Just copy these definitions to the end of avrdude.conf, which can be found in /etc, /usr/local/etc, or (on Windows) C:\WinAVR-*\bin. This will be most useful for Windows users, since the latest WinAVR does not support the 328.

#------------------------------------------------------------
# ATmega328P
#------------------------------------------------------------

part
id              = "m328p";
desc            = "ATMEGA328P";
has_debugwire = yes;
flash_instr   = 0xB6, 0x01, 0x11;
eeprom_instr  = 0xBD, 0xF2, 0xBD, 0xE1, 0xBB, 0xCF, 0xB4, 0x00,
0xBE, 0x01, 0xB6, 0x01, 0xBC, 0x00, 0xBB, 0xBF,
0x99, 0xF9, 0xBB, 0xAF;
stk500_devcode  = 0x86;
# avr910_devcode = 0x;
signature       = 0x1e 0x95 0x0F;
pagel           = 0xd7;
bs2             = 0xc2;
chip_erase_delay = 9000;
pgm_enable       = "1 0 1 0 1 1 0 0 0 1 0 1 0 0 1 1",
"x x x x x x x x x x x x x x x x";

chip_erase       = "1 0 1 0 1 1 0 0 1 0 0 x x x x x",
"x x x x x x x x x x x x x x x x";

timeout         = 200;
stabdelay       = 100;
cmdexedelay     = 25;
synchloops      = 32;
bytedelay       = 0;
pollindex       = 3;
pollvalue       = 0x53;
predelay        = 1;
postdelay       = 1;
pollmethod      = 1;

pp_controlstack     =
0x0E, 0x1E, 0x0F, 0x1F, 0x2E, 0x3E, 0x2F, 0x3F,
0x4E, 0x5E, 0x4F, 0x5F, 0x6E, 0x7E, 0x6F, 0x7F,
0x66, 0x76, 0x67, 0x77, 0x6A, 0x7A, 0x6B, 0x7B,
0xBE, 0xFD, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00;
hventerstabdelay    = 100;
progmodedelay       = 0;
latchcycles         = 5;
togglevtg           = 1;
poweroffdelay       = 15;
resetdelayms        = 1;
resetdelayus        = 0;
hvleavestabdelay    = 15;
resetdelay          = 15;
chiperasepulsewidth = 0;
chiperasepolltimeout = 10;
programfusepulsewidth = 0;
programfusepolltimeout = 5;
programlockpulsewidth = 0;
programlockpolltimeout = 5;

memory "eeprom"
paged           = no;
page_size       = 4;
size            = 1024;
min_write_delay = 3600;
max_write_delay = 3600;
read            = " 1 0 1 0 0 0 0 0",
" 0 0 0 x x x a9 a8",
" a7 a6 a5 a4 a3 a2 a1 a0",
" o o o o o o o o";

write           = " 1 1 0 0 0 0 0 0",
" 0 0 0 x x x a9 a8",
" a7 a6 a5 a4 a3 a2 a1 a0",
" i i i i i i i i";

loadpage_lo     = "  1   1   0   0      0   0   0   1",
"  0   0   0   0      0   0   0   0",
"  0   0   0   0      0   0  a1  a0",
"  i   i   i   i      i   i   i   i";

writepage       = "  1   1   0   0      0   0   1   0",
"  0   0   x   x      x   x   a9  a8",
" a7  a6  a5  a4     a3  a2   0   0",
"  x   x   x   x      x   x   x   x";

mode            = 0x41;
delay           = 5;
blocksize       = 4;
;

memory "flash"
paged           = yes;
size            = 32768;
page_size       = 128;
num_pages       = 256;
min_write_delay = 4500;
max_write_delay = 4500;
read_lo         = " 0 0 1 0 0 0 0 0",
" 0 0 a13 a12 a11 a10 a9 a8",
" a7 a6 a5 a4 a3 a2 a1 a0",
" o o o o o o o o";

read_hi          = " 0 0 1 0 1 0 0 0",
" 0 0 a13 a12 a11 a10 a9 a8",
" a7 a6 a5 a4 a3 a2 a1 a0",
" o o o o o o o o";

loadpage_lo     = " 0 1 0 0 0 0 0 0",
" 0 0 0 x x x x x",
" x x a5 a4 a3 a2 a1 a0",
" i i i i i i i i";

loadpage_hi     = " 0 1 0 0 1 0 0 0",
" 0 0 0 x x x x x",
" x x a5 a4 a3 a2 a1 a0",
" i i i i i i i i";

writepage       = " 0 1 0 0 1 1 0 0",
" 0 0 a13 a12 a11 a10 a9 a8",
" a7 a6 x x x x x x",
" x x x x x x x x";

mode        = 0x41;
delay       = 6;
blocksize   = 128;

;

memory "lfuse"
size            = 1;
min_write_delay = 4500;
max_write_delay = 4500;
read            = "0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0",
"x x x x x x x x o o o o o o o o";

write           = "1 0 1 0 1 1 0 0 1 0 1 0 0 0 0 0",
"x x x x x x x x i i i i i i i i";
;

memory "hfuse"
size            = 1;
min_write_delay = 4500;
max_write_delay = 4500;
read            = "0 1 0 1 1 0 0 0 0 0 0 0 1 0 0 0",
"x x x x x x x x o o o o o o o o";

write           = "1 0 1 0 1 1 0 0 1 0 1 0 1 0 0 0",
"x x x x x x x x i i i i i i i i";
;

memory "efuse"
size            = 1;
min_write_delay = 4500;
max_write_delay = 4500;
read            = "0 1 0 1 0 0 0 0 0 0 0 0 1 0 0 0",
"x x x x x x x x x x x x x o o o";

write           = "1 0 1 0 1 1 0 0 1 0 1 0 0 1 0 0",
"x x x x x x x x x x x x x i i i";
;

memory "lock"
size            = 1;
min_write_delay = 4500;
max_write_delay = 4500;
read            = "0 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0",
"x x x x x x x x x x o o o o o o";

write           = "1 0 1 0 1 1 0 0 1 1 1 x x x x x",
"x x x x x x x x 1 1 i i i i i i";
;

memory "calibration"
size            = 1;
read            = "0 0 1 1 1 0 0 0 0 0 0 x x x x x",
"0 0 0 0 0 0 0 0 o o o o o o o o";
;

memory "signature"
size            = 3;
read            = "0 0 1 1 0 0 0 0 0 0 0 x x x x x",
"x x x x x x a1 a0 o o o o o o o o";
;
;

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