Initial commit

LICENSE

+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+ 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.

Makefile

+# WinAVR Sample makefile written by Eric B. Weddington, Jörg Wunsch, et al.
+# Released to the Public Domain
+# Please read the make user manual!
+#
+# Additional material for this makefile was submitted by:
+#  Tim Henigan
+#  Peter Fleury
+#  Reiner Patommel
+#  Sander Pool
+#  Frederik Rouleau
+#  Markus Pfaff
+#
+# On command line:
+#
+# make all = Make software.
+#
+# make clean = Clean out built project files.
+#
+# make coff = Convert ELF to AVR COFF (for use with AVR Studio 3.x or VMLAB).
+#
+# make extcoff = Convert ELF to AVR Extended COFF (for use with AVR Studio
+#                4.07 or greater).
+#
+# make program = Download the hex file to the device, using avrdude.  Please
+#                customize the avrdude settings below first!
+#
+# make filename.s = Just compile filename.c into the assembler code only
+#
+# To rebuild project do "make clean" then "make all".
+#
+
+# MCU name
+
+#MCU = atmega644p
+MCU = atmega32
+
+
+#ATmega 128 wird von mir nicht unterstützt oder nur teilweise! 
+#MCU = atmega128  
+
+#Fuse settings for ATmega1284P
+ifeq ($(MCU), atmega1284p)
+	FUSE_BITS = -u -U lfuse:w:0xff:m -U hfuse:w:0xd9:m
+	HEX_FILE_NAME = MEGA1284
+endif
+
+#Fuse settings for ATmega644
+ifeq ($(MCU), atmega644)
+	FUSE_BITS = -u -U lfuse:w:0xff:m -U hfuse:w:0xdf:m
+	HEX_FILE_NAME = MEGA644
+endif
+
+#Fuse settings for ATmega644P
+ifeq ($(MCU), atmega644p)
+	FUSE_BITS = -u -U lfuse:w:0xff:m -U hfuse:w:0xdf:m
+	HEX_FILE_NAME = MEGA644_P
+endif
+
+#Fuse settings for ATmega32
+ifeq ($(MCU), atmega32)
+	FUSE_BITS = -u -U lfuse:w:0xff:m -U hfuse:w:0xcf:m
+	HEX_FILE_NAME = MEGA32
+endif
+
+#Fuse settings for ATmega128 zurzeit nur für RTL8019-Karten
+ifeq ($(MCU), atmega128)
+	#FUSE_BITS = -u -U lfuse:w:0xff:m -U hfuse:w:0xcf:m
+	HEX_FILE_NAME = MEGA128
+endif
+
+# Output format. (can be srec, ihex, binary)
+FORMAT = ihex
+
+# Target file name (without extension).
+TARGET = out/portal_$(HEX_FILE_NAME)
+
+# Optimization level, can be [0, 1, 2, 3, s]. 0 turns off optimization.
+# (Note: 3 is not always the best optimization level. See avr-libc FAQ.)
+OPT = s
+
+# If there is more than one source file, append them above, or modify and
+# uncomment the following:
+
+SRC = $(shell find . -name '*.c')
+
+#SRC =  main.c 
+
+# List Assembler source files here.
+# Make them always end in a capital .S.  Files ending in a lowercase .s
+# will not be considered source files but generated files (assembler
+# output from the compiler), and will be deleted upon "make clean"!
+# Even though the DOS/Win* filesystem matches both .s and .S the same,
+# it will preserve the spelling of the filenames, and gcc itself does
+# care about how the name is spelled on its command-line.
+ASRC = 
+
+
+# List any extra directories to look for include files here.
+#     Each directory must be seperated by a space.
+EXTRAINCDIRS = 
+
+
+# Optional compiler flags.
+#  -g:        generate debugging information (for GDB, or for COFF conversion)
+#  -O*:       optimization level
+#  -f...:     tuning, see gcc manual and avr-libc documentation
+#  -Wall...:  warning level
+#  -Wa,...:   tell GCC to pass this to the assembler.
+#    -ahlms:  create assembler listing
+CFLAGS = -g -O$(OPT) \
+-funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums \
+-Wall -Wstrict-prototypes \
+-Wa,-adhlns=$(<:.c=.lst) \
+$(patsubst %,-I%,$(EXTRAINCDIRS))
+
+
+# Set a "language standard" compiler flag.
+#   Unremark just one line below to set the language standard to use.
+#   gnu99 = C99 + GNU extensions. See GCC manual for more information.
+#CFLAGS += -std=c89
+#CFLAGS += -std=gnu89
+#CFLAGS += -std=c99
+CFLAGS += -std=gnu99
+
+
+
+# Optional assembler flags.
+#  -Wa,...:   tell GCC to pass this to the assembler.
+#  -ahlms:    create listing
+#  -gstabs:   have the assembler create line number information; note that
+#             for use in COFF files, additional information about filenames
+#             and function names needs to be present in the assembler source
+#             files -- see avr-libc docs [FIXME: not yet described there]
+ASFLAGS = -Wa,-adhlns=$(<:.S=.lst),-gstabs 
+
+
+
+# Optional linker flags.
+#  -Wl,...:   tell GCC to pass this to linker.
+#  -Map:      create map file
+#  --cref:    add cross reference to  map file
+LDFLAGS = -Wl,-Map=$(TARGET).map,--cref
+
+
+
+# Additional libraries
+
+# Minimalistic printf version
+#LDFLAGS += -Wl,-u,vfprintf -lprintf_min
+
+# Floating point printf version (requires -lm below)
+#LDFLAGS += -Wl,-u,vfprintf -lprintf_flt
+
+# -lm = math library
+LDFLAGS += -lm
+
+
+
+
+# Programming support using avrdude. Settings and variables.
+
+# Programming hardware: alf avr910 avrisp bascom bsd 
+# dt006 pavr picoweb pony-stk200 sp12 stk200 stk500
+#
+# Type: avrdude -c ?
+# to get a full listing.
+#
+
+#AVRDUDE_PROGRAMMER = AVR910
+AVRDUDE_PROGRAMMER = usbtiny
+# AVRDUDE_PROGRAMMER = USBasp
+
+AVRDUDE_PORT = usb        # programmer connected to USB port
+#AVRDUDE_PORT = com1	   # programmer connected to serial device
+#AVRDUDE_PORT = lpt1	       # programmer connected to parallel port
+
+AVRDUDE_WRITE_FLASH = -U flash:w:$(TARGET).hex $(FUSE_BITS)
+#AVRDUDE_WRITE_EEPROM = -U eeprom:w:$(TARGET).eep
+
+#AVRDUDE_FLAGS = -p $(MCU) -P $(AVRDUDE_PORT) -b 115200 -c $(AVRDUDE_PROGRAMMER)
+AVRDUDE_FLAGS = -B 1 -p $(MCU) -P $(AVRDUDE_PORT) -c $(AVRDUDE_PROGRAMMER)
+
+# Uncomment the following if you want avrdude's erase cycle counter.
+# Note that this counter needs to be initialized first using -Yn,
+# see avrdude manual.
+#AVRDUDE_ERASE += -y
+
+# Uncomment the following if you do /not/ wish a verification to be
+# performed after programming the device.
+#AVRDUDE_FLAGS += -V
+
+# Increase verbosity level.  Please use this when submitting bug
+# reports about avrdude. See <http://savannah.nongnu.org/projects/avrdude> 
+# to submit bug reports.
+#AVRDUDE_FLAGS += -v -v
+
+
+
+
+# ---------------------------------------------------------------------------
+
+# Define programs and commands.
+SHELL = sh
+
+CC = avr-gcc
+
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+SIZE = avr-size
+
+
+# Programming support using avrdude.
+AVRDUDE = avrdude
+
+
+REMOVE = rm -f
+COPY = cp
+
+HEXSIZE = $(SIZE) --target=$(FORMAT) $(TARGET).hex
+ELFSIZE = $(SIZE) -A $(TARGET).elf
+
+
+
+# Define Messages
+# English
+MSG_ERRORS_NONE = Errors: none
+MSG_BEGIN = -------- begin --------
+MSG_END = --------  end  --------
+MSG_SIZE_BEFORE = Size before: 
+MSG_SIZE_AFTER = Size after:
+MSG_COFF = Converting to AVR COFF:
+MSG_EXTENDED_COFF = Converting to AVR Extended COFF:
+MSG_FLASH = Creating load file for Flash:
+MSG_EEPROM = Creating load file for EEPROM:
+MSG_EXTENDED_LISTING = Creating Extended Listing:
+MSG_SYMBOL_TABLE = Creating Symbol Table:
+MSG_LINKING = Linking:
+MSG_COMPILING = Compiling:
+MSG_ASSEMBLING = Assembling:
+MSG_CLEANING = Cleaning project:
+
+
+
+
+# Define all object files.
+OBJ = $(SRC:.c=.o) $(ASRC:.S=.o) 
+
+# Define all listing files.
+LST = $(ASRC:.S=.lst) $(SRC:.c=.lst)
+
+# Combine all necessary flags and optional flags.
+# Add target processor to flags.
+ALL_CFLAGS = -mmcu=$(MCU) -I. $(CFLAGS)
+ALL_ASFLAGS = -mmcu=$(MCU) -I. -x assembler-with-cpp $(ASFLAGS)
+
+
+
+# Default target.
+all: begin gccversion sizebefore $(TARGET).elf $(TARGET).hex $(TARGET).eep \
+	$(TARGET).lss $(TARGET).sym sizeafter finished end
+
+
+# Eye candy.
+# AVR Studio 3.x does not check make's exit code but relies on
+# the following magic strings to be generated by the compile job.
+begin:
+	@echo
+	@echo $(MSG_BEGIN)
+
+finished:
+	@echo $(MSG_ERRORS_NONE)
+
+end:
+	@echo $(MSG_END)
+	@echo
+
+
+# Display size of file.
+sizebefore:
+	@if [ -f $(TARGET).elf ]; then echo; echo $(MSG_SIZE_BEFORE); $(ELFSIZE); echo; fi
+
+sizeafter:
+	@if [ -f $(TARGET).elf ]; then echo; echo $(MSG_SIZE_AFTER); $(ELFSIZE); echo; fi
+
+
+
+# Display compiler version information.
+gccversion : 
+	@$(CC) --version
+
+
+
+
+# Convert ELF to COFF for use in debugging / simulating in
+# AVR Studio or VMLAB.
+COFFCONVERT=$(OBJCOPY) --debugging \
+	--change-section-address .data-0x800000 \
+	--change-section-address .bss-0x800000 \
+	--change-section-address .noinit-0x800000 \
+	--change-section-address .eeprom-0x810000 
+
+
+coff: $(TARGET).elf
+	@echo
+	@echo $(MSG_COFF) $(TARGET).cof
+	$(COFFCONVERT) -O coff-avr $< $(TARGET).cof
+
+
+extcoff: $(TARGET).elf
+	@echo
+	@echo $(MSG_EXTENDED_COFF) $(TARGET).cof
+	$(COFFCONVERT) -O coff-ext-avr $< $(TARGET).cof
+
+
+
+
+# Program the device.  
+program: $(TARGET).hex $(TARGET).eep
+	$(AVRDUDE) $(AVRDUDE_FLAGS) $(AVRDUDE_WRITE_FLASH) $(AVRDUDE_WRITE_EEPROM)
+
+
+
+
+# Create final output files (.hex, .eep) from ELF output file.
+%.hex: %.elf
+	@echo
+	@echo $(MSG_FLASH) $@
+	$(OBJCOPY) -O $(FORMAT) -R .eeprom $< $@
+
+%.eep: %.elf
+	@echo
+	@echo $(MSG_EEPROM) $@
+	-$(OBJCOPY) -j .eeprom --set-section-flags=.eeprom="alloc,load" \
+	--change-section-lma .eeprom=0 -O $(FORMAT) $< $@
+
+# Create extended listing file from ELF output file.
+%.lss: %.elf
+	@echo
+	@echo $(MSG_EXTENDED_LISTING) $@
+	$(OBJDUMP) -h -S $< > $@
+
+# Create a symbol table from ELF output file.
+%.sym: %.elf
+	@echo
+	@echo $(MSG_SYMBOL_TABLE) $@
+	avr-nm -n $< > $@
+
+
+
+# Link: create ELF output file from object files.
+.SECONDARY : $(TARGET).elf
+.PRECIOUS : $(OBJ)
+%.elf: $(OBJ)
+	@echo
+	@echo $(MSG_LINKING) $@
+	$(CC) $(ALL_CFLAGS) $(OBJ) --output $@ $(LDFLAGS)
+
+
+# Compile: create object files from C source files.
+%.o : %.c
+	@echo
+	@echo $(MSG_COMPILING) $<
+	$(CC) -c $(ALL_CFLAGS) $< -o $@
+
+
+# Compile: create assembler files from C source files.
+%.s : %.c
+	$(CC) -S $(ALL_CFLAGS) $< -o $@
+
+
+# Assemble: create object files from assembler source files.
+%.o : %.S
+	@echo
+	@echo $(MSG_ASSEMBLING) $<
+	$(CC) -c $(ALL_ASFLAGS) $< -o $@
+
+
+
+
+
+
+# Target: clean project.
+clean: begin clean_list finished end
+
+clean_list :
+	@echo
+	@echo $(MSG_CLEANING)
+#	$(REMOVE) $(TARGET).hex
+	$(REMOVE) $(TARGET).eep
+	$(REMOVE) $(TARGET).obj
+	$(REMOVE) $(TARGET).cof
+	$(REMOVE) $(TARGET).elf
+	$(REMOVE) $(TARGET).map
+	$(REMOVE) $(TARGET).obj
+	$(REMOVE) $(TARGET).a90
+	$(REMOVE) $(TARGET).sym
+	$(REMOVE) $(TARGET).lnk
+	$(REMOVE) $(TARGET).lss
+	$(REMOVE) $(OBJ)
+	$(REMOVE) $(LST)
+	$(REMOVE) $(SRC:.c=.s)
+	$(REMOVE) $(SRC:.c=.d)
+
+
+# Automatically generate C source code dependencies. 
+# (Code originally taken from the GNU make user manual and modified 
+# (See README.txt Credits).)
+#
+# Note that this will work with sh (bash) and sed that is shipped with WinAVR
+# (see the SHELL variable defined above).
+# This may not work with other shells or other seds.
+#
+%.d: %.c
+	set -e; $(CC) -MM $(ALL_CFLAGS) $< \
+	| sed 's,\(.*\)\.o[ :]*,\1.o \1.d : ,g' > $@; \
+	[ -s $@ ] || rm -f $@
+
+
+# Remove the '-' if you want to see the dependency files generated.
+-include $(SRC:.c=.d)
+
+
+
+# Listing of phony targets.
+.PHONY : all begin finish end sizebefore sizeafter gccversion coff extcoff \
+	clean clean_list program
+

common/simple_serial.h

+#ifndef _SIMPLE_SERIAL_H
+
+#include <stdlib.h>
+#include <avr/io.h> 
+
+#define BAUD 38400
+
+#ifndef UBRRH
+	#define UBRRH UBRR0H
+	#define UBRRL UBRR0L
+	#define UCSRA UCSR0A
+	#define UCSRB UCSR0B
+	#define UCSRC UCSR0C
+	#define UCSZ0 UCSZ00
+	#define UCSZ1 UCSZ01
+	#define USBS  USBS0
+	#define RXEN  RXEN0
+	#define TXEN  TXEN0
+	#define UCSRA UCSR0A
+	#define UDRE  UDRE0
+	#define UDR   UDR0
+	#define RXC   RXC0
+	#define U2X   U2X0
+#endif
+	
+
+#ifdef USART_USE_AS_STDOUT //Sets up the serial port as a stream for stdout. With this printf and stuff will write to the serial port.
+	#include <stdio.h>
+	
+	void USART_transmit_char(unsigned char data);
+	
+	void USART_transmit_stdout(char c, FILE* stream){
+		USART_transmit_char((unsigned char)c);
+	}
+
+    static FILE USART_stdout = FDEV_SETUP_STREAM(USART_transmit_stdout, NULL, _FDEV_SETUP_WRITE);
+	
+#endif
+
+
+void USART_init(void){
+	//Set bit rate
+	#include <util/setbaud.h>
+	UBRRH = UBRRH_VALUE;
+	UBRRL = UBRRL_VALUE;
+	#if USE_2X
+		UCSRA |= (1 << U2X);
+	#else
+		UCSRA &= ~(1 << U2X);
+	#endif
+	
+	//Set frame format: 8data, 1stop bit
+	#ifdef URSEL
+		UCSRC = (1<<UCSZ0) | (1<<UCSZ1) | (1<<USBS) | (1<<URSEL);
+	#else
+		UCSRC = (1<<UCSZ0) | (1<<UCSZ1) | (1<<USBS);
+	#endif
+	//Enable receiver, transmitter
+	UCSRB = (1<<RXEN) | (1<<TXEN);
+	
+	#ifdef USART_USE_AS_STDOUT
+		stdout = &USART_stdout; //assign serial output stream as stdout.
+	#endif
+}
+
+
+void USART_transmit_char(unsigned char data){
+	//Wait for empty transmit buffer
+	while ( !( UCSRA & (1 << UDRE)) ) {;}
+	//Put data into buffer, sends the data
+	UDR = data;
+}
+
+void USART_transmit_buffer(unsigned char* data, unsigned char length){
+	for (unsigned char i = 0; i < length; i++){
+		while ( !( UCSRA & (1 << UDRE)) ) {;} //Wait for empty transmit buffer
+		UDR = data[i];
+	}
+}
+
+unsigned char USART_data_available(void) {
+	return (UCSRA & (1 << RXC)) != 0;
+}
+
+unsigned char USART_read_char(void) {
+	//Wait for data to arrive
+	while (!(UCSRA & (1 << RXC))) {;}
+	//Return received data
+	return UDR;
+}
+
+void USART_read_buffer(unsigned char* buf, unsigned char length) {
+	while (length != 0){
+		//Wait for data to arrive
+		while (!(UCSRA & (1 << RXC))) {;}
+		buf[0] = UDR; //write byte to buffer
+		buf++; //go to next byte in buffer
+		length--; //one byte less to read
+	}
+}
+
+#define _SIMPLE_SERIAL_H
+#endif
\ No newline at end of file

common/simple_timer.h

+#ifndef TIMER_H
+#define TIMER_H
+
+#include <avr/interrupt.h> 
+
+#define CLOCK_SOURCE_DISABLED 0
+#define CLOCK_SOURCE_CPU_CLK 1
+#define CLOCK_SOURCE_CPU_CLK_DIV8 2
+#define CLOCK_SOURCE_CPU_CLK_DIV64 3
+#define CLOCK_SOURCE_CPU_CLK_DIV256 4
+#define CLOCK_SOURCE_CPU_CLK_DIV1024 5
+#define CLOCK_SOURCE_T0_PIN_FALL_EDGE 6
+#define CLOCK_SOURCE_T0_PIN_RAISE_EDGE 7
+
+#define TIMER_OVERFLOW_INTERUPT_ENABLE (1<<TOIE0)
+
+#if   F_CPU == 16000000
+	#define INTERRUPTS_PER_MS 8
+	#define TIMER_INIT_VALUE 6 //initialize counter to 6. We want to count for 250 steps to get 250 msec resolution, not 256
+#elif   F_CPU == 8000000
+	#define INTERRUPTS_PER_MS 4
+	#define TIMER_INIT_VALUE 6 //initialize counter to 6. We want to count for 250 steps to get 250 msec resolution, not 256
+#elif F_CPU == 4000000
+	#define INTERRUPTS_PER_MS 2
+	#define TIMER_INIT_VALUE 6 //initialize counter to 6. We want to count for 250 steps to get 250 msec resolution, not 256
+#elif F_CPU == 2000000
+	#define INTERRUPTS_PER_MS 1
+	#define TIMER_INIT_VALUE 6 //initialize counter to 6. We want to count for 250 steps to get 250 msec resolution, not 256
+#elif F_CPU == 1000000
+	#define INTERRUPTS_PER_MS 1
+	#define TIMER_INIT_VALUE 131 //initialize counter to 131. We want to count for 125 steps to get 250 msec resolution, not 256
+#else
+	#error "Unknown CPU Freq! Timer will not work properly"
+#endif
+
+
+#ifndef TCCR0
+	#define TCCR0 TCCR0B //some chips (e.g. ATTiny2313 have an two TCCR0 registers, the B one is what we want)
+#endif
+
+#ifndef TIMSK
+	#define TIMSK TIMSK0
+#endif
+
+
+extern void timer_handler(void);
+
+volatile unsigned int timer_interrupt_counter = 0; //interrupts since last ms timer event (counts up to INTERRUPTS_PER_MS)
+volatile unsigned int timer_interval;
+
+void timer_init(unsigned int interval){
+	timer_interval = interval * INTERRUPTS_PER_MS;
+	
+	TCCR0 = CLOCK_SOURCE_CPU_CLK_DIV8; //clock source is CPU clock, count every 8 cycles.
+	TCNT0 = TIMER_INIT_VALUE;
+	timer_interrupt_counter = 0;
+	TIMSK |= TIMER_OVERFLOW_INTERUPT_ENABLE; //enable timer overflow interrupt.
+}
+
+void timer_stop(void){
+	TCCR0 = CLOCK_SOURCE_DISABLED;
+	TIMSK &= (unsigned char)~TIMER_OVERFLOW_INTERUPT_ENABLE;
+}
+	
+
+#ifndef TIM0_OVF_vect
+	#define TIM0_OVF_vect TIMER0_OVF_vect
+#endif
+
+ISR(TIM0_OVF_vect){
+	TCNT0 += TIMER_INIT_VALUE;
+		
+	timer_interrupt_counter++;
+	if (timer_interrupt_counter >= timer_interval){
+		timer_interrupt_counter = 0;
+		timer_handler();
+	}
+}
+
+
+
+#endif
\ No newline at end of file

main.c

+#define F_CPU 16000000UL  // 16 MHz
+
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+
+#define USART_USE_AS_STDOUT
+#include <common/simple_serial.h>
+
+#include <common/simple_timer.h>
+
+#define COMMAND_UNLOCK_PIN  2
+#define COMMAND_LOCK_PIN    3
+
+#define STATUS_UNLOCKED_PIN 4
+#define STATUS_LOCKED_PIN   5
+#define STATUS_OPEN_PIN     6
+#define STATUS_ALARM_PIN    7
+#define STATUS_PIN_OFFSET 4
+#define STATUS_PIN_MASK   ((1 << STATUS_UNLOCKED_PIN) | (1 << STATUS_LOCKED_PIN) | (1 << STATUS_OPEN_PIN) | (1 << STATUS_ALARM_PIN))
+#define STATUS_PIN_FLIP   ((1 << STATUS_UNLOCKED_PIN) | (1 << STATUS_LOCKED_PIN))
+
+#define DOOR_PORT PORTC
+#define DOOR_DDR  DDRC
+#define DOOR_PIN  PINC
+
+
+#define DOOR_STATUS_LOCKED   0
+#define DOOR_STATUS_CHANGING 1
+#define DOOR_STATUS_UNLOCKED 2
+#define DOOR_STATUS_OPEN     3
+
+#define DOOR_STATUS_ALARM    4
+#define DOOR_STATUS_ERROR    5
+
+char* status_strings[6] = {"Locked", "Changing", "Unlocked", "Open", "Alarm", "Error"};
+
+/*
+PIN - UNLOCKED | LOCKED | OPEN | ALARM => STATUS
+         0         0       0       0   => DOOR_STATUS_CHANGING
+         1         0       0       0   => DOOR_STATUS_UNLOCKED
+         0         1       0       0   => DOOR_STATUS_LOCKED
+         1         1       0       0   => DOOR_STATUS_ERROR
+         0         0       1       0   => DOOR_STATUS_ALARM
+         1         0       1       0   => DOOR_STATUS_OPEN
+         0         1       1       0   => DOOR_STATUS_ALARM
+         1         1       1       0   => DOOR_STATUS_ALARM
+         *         *       *       1   => DOOR_STATUS_ALARM
+*/
+
+uint8_t status_mapping[16] = {DOOR_STATUS_CHANGING,
+                              DOOR_STATUS_UNLOCKED,
+							  DOOR_STATUS_LOCKED,
+							  DOOR_STATUS_ERROR,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_OPEN,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM,
+							  DOOR_STATUS_ALARM};
+
+const char ACTION[]           PROGMEM = "Action ";
+const char ERROR[]            PROGMEM = "Error ";
+const char STATUS[]           PROGMEM = "Status ";
+const char ALREADY_LOCKED[]   PROGMEM = "Already locked\n";
+const char BUSY[]             PROGMEM = "Busy\n";
+const char LOCKING[]          PROGMEM = "Locking\n";
+const char DOOR_OPEN[]        PROGMEM = "Door open\n";
+const char DOOR_ALARM[]       PROGMEM = "Door Alarm\n";
+const char DOOR_STATE_ERROR[] PROGMEM = "Door State Error\n";
+const char UNLOCKING[]        PROGMEM = "Unlocking\n";
+const char ALREADY_UNLOCKED[] PROGMEM = "Already unlocked\n";
+const char UNKNOWN_COMMAND[]  PROGMEM = "Unknown Command\n";
+const char ALARM_STOP[]       PROGMEM = "Alarm Stop\n";
+
+void timer_handler(){
+	PORTD ^= (1 << 7);
+}
+
+void lock(void){
+	DOOR_PORT &= (uint8_t)~(1 << COMMAND_UNLOCK_PIN);
+	DOOR_PORT |= (1 << COMMAND_LOCK_PIN);
+	_delay_ms(10); //TODO: Figure out the required length or do this in background if needed
+	DOOR_PORT &= (uint8_t)~(1 << COMMAND_LOCK_PIN);
+}
+void unlock(void){
+	DOOR_PORT &= (uint8_t)~(1 << COMMAND_LOCK_PIN);
+	DOOR_PORT |= (1 << COMMAND_UNLOCK_PIN);
+	_delay_ms(10);
+	DOOR_PORT &= (uint8_t)~(1 << COMMAND_UNLOCK_PIN);
+}
+
+void alarm_start(){
+	timer_init(1);
+	sei();
+}
+void alarm_stop(){
+	timer_stop();
+	cli();
+}
+
+uint8_t get_door_status(void){
+	uint8_t status_pins_ref;
+	uint8_t status_pins;
+	while (1){
+		status_pins_ref = DOOR_PIN & STATUS_PIN_MASK;
+		for (uint8_t i = 0; i < 10; i++){
+			_delay_us(100);
+			status_pins = DOOR_PIN & STATUS_PIN_MASK;
+			if (status_pins != status_pins_ref) break;
+		}
+		if (status_pins == status_pins_ref) break;
+	}
+// 	printf("Pin %02X\n", status_pins);
+	status_pins ^= STATUS_PIN_FLIP; //flip bits for active low pins so that "bit set" always means active.
+
+	return status_mapping[status_pins >> STATUS_PIN_OFFSET];
+}
+
+int main(void){
+	DOOR_DDR = (1 << COMMAND_UNLOCK_PIN) | (1 << COMMAND_LOCK_PIN);
+	//Use internal PullUp Resistors for (active-low inputs)
+	DOOR_PORT = (1 << STATUS_UNLOCKED_PIN) | (1 << STATUS_LOCKED_PIN) | (1 << STATUS_OPEN_PIN) | (1 << STATUS_ALARM_PIN);
+	
+	DDRD |= (1 << 7); //Alarm pin
+	
+	USART_init();
+	
+	
+	printf_P(PSTR("\n== Yo! ==\n"));
+	
+	uint8_t last_door_status = 0xFF;
+	uint8_t door_status = 0;
+
+	while(1){
+		door_status = get_door_status();
+		
+		if (last_door_status != door_status){
+			last_door_status = door_status;
+			printf_P(STATUS);
+			printf(status_strings[door_status]);
+			USART_transmit_char('\n');
+			if (door_status == DOOR_STATUS_ALARM){
+				alarm_start();
+			}
+		}
+		
+		
+		
+		if (USART_data_available()){
+			char c = USART_read_char();
+// 			USART_transmit_char(c);
+			
+			switch (c){
+				case 'l':
+				case 'L':
+					switch (door_status){
+						case DOOR_STATUS_LOCKED:
+							printf_P(ERROR);
+							printf_P(ALREADY_LOCKED);
+							break;
+						case DOOR_STATUS_CHANGING:
+							printf_P(ERROR);
+							printf_P(BUSY);
+							break;
+						case DOOR_STATUS_UNLOCKED:
+							lock(); // <---------- magic happens here ;)
+							printf_P(ACTION);
+							printf_P(LOCKING);
+							break;
+						case DOOR_STATUS_OPEN:
+							printf_P(ERROR);
+							printf_P(DOOR_OPEN);
+							break;
+						case DOOR_STATUS_ALARM:
+							printf_P(ERROR);
+							printf_P(DOOR_ALARM);
+							break;
+						case DOOR_STATUS_ERROR:
+							printf_P(ERROR);
+							printf_P(DOOR_STATE_ERROR);
+							break;
+					}
+					break;
+					
+				case 'u':
+				case 'U':
+					switch (door_status){
+						case DOOR_STATUS_LOCKED:
+							unlock(); // <---------- magic happens here ;)
+							printf_P(ACTION);
+							printf_P(UNLOCKING);
+							break;
+						case DOOR_STATUS_CHANGING:
+							printf_P(ERROR);
+							printf_P(BUSY);
+							break;
+						case DOOR_STATUS_UNLOCKED:
+							printf_P(ERROR);
+							printf_P(ALREADY_UNLOCKED);
+							break;
+						case DOOR_STATUS_OPEN:
+							printf_P(ERROR);
+							printf_P(DOOR_OPEN);
+							break;
+						case DOOR_STATUS_ALARM:
+							printf_P(ERROR);
+							printf_P(DOOR_ALARM);
+							break;
+						case DOOR_STATUS_ERROR:
+							printf_P(ERROR);
+							printf_P(DOOR_STATE_ERROR);
+							break;
+					}
+					break;
+				case 'a':
+				case 'A':
+					alarm_stop();
+					printf_P(ACTION);
+					printf_P(ALARM_STOP);
+					break;
+				case '\n':
+				case '\r':
+					USART_transmit_char(c);
+					break;
+				case '\0':
+					break;
+				default:
+					printf_P(ERROR);
+					printf_P(UNKNOWN_COMMAND);
+			}
+			
+		}
+	}
+}
\ No newline at end of file