AVR Freaks

# Name: Makefile
# Author: 
# Copyright: 
# License: 

# This is a prototype Makefile. Modify it according to your needs.
# You should at least check the settings for
# DEVICE ....... The AVR device you compile for
# CLOCK ........ Target AVR clock rate in Hertz
# OBJECTS ...... The object files created from your source files. This list is
#                usually the same as the list of source files with suffix ".o".
# PROGRAMMER ... Options to avrdude which define the hardware you use for
#                uploading to the AVR and the interface where this hardware
#                is connected.
# FUSES ........ Parameters for avrdude to flash the fuses appropriately.

DEVICE     = atmega8
CLOCK      = 8000000
PROGRAMMER = -c stk500v2 -P /dev/tty.usbserial-A3000HDB
OBJECTS    = main.o
FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
# ATMega8 fuse bits (fuse bits for other devices are different!):
# Example for 8 MHz internal oscillator
# Fuse high byte:
# 0xd9 = 1 1 0 1   1 0 0 1 <-- BOOTRST (boot reset vector at 0x0000)
#        ^ ^ ^ ^   ^ ^ ^------ BOOTSZ0
#        | | | |   | +-------- BOOTSZ1
#        | | | |   +---------- EESAVE (set to 0 to preserve EEPROM over chip erase)
#        | | | +-------------- CKOPT (clock option, depends on oscillator type)
#        | | +---------------- SPIEN (if set to 1, serial programming is disabled)
#        | +------------------ WDTON (if set to 0, watchdog is always on)
#        +-------------------- RSTDISBL (if set to 0, RESET pin is disabled)
# Fuse low byte:
# 0x24 = 0 0 1 0   0 1 0 0
#        ^ ^ \ /   \--+--/
#        | |  |       +------- CKSEL 3..0 (8M internal RC)
#        | |  +--------------- SUT 1..0 (slowly rising power)
#        | +------------------ BODEN (if 0, brown-out detector is enabled)
#        +-------------------- BODLEVEL (if 0: 4V, if 1: 2.7V)

# Example for 12 MHz external crystal:
# Fuse high byte:
# 0xc9 = 1 1 0 0   1 0 0 1 <-- BOOTRST (boot reset vector at 0x0000)
#        ^ ^ ^ ^   ^ ^ ^------ BOOTSZ0
#        | | | |   | +-------- BOOTSZ1
#        | | | |   +---------- EESAVE (set to 0 to preserve EEPROM over chip erase)
#        | | | +-------------- CKOPT (clock option, depends on oscillator type)
#        | | +---------------- SPIEN (if set to 1, serial programming is disabled)
#        | +------------------ WDTON (if set to 0, watchdog is always on)
#        +-------------------- RSTDISBL (if set to 0, RESET pin is disabled)
# Fuse low byte:
# 0x9f = 1 0 0 1   1 1 1 1
#        ^ ^ \ /   \--+--/
#        | |  |       +------- CKSEL 3..0 (external >8M crystal)
#        | |  +--------------- SUT 1..0 (crystal osc, BOD enabled)
#        | +------------------ BODEN (if 0, brown-out detector is enabled)
#        +-------------------- BODLEVEL (if 0: 4V, if 1: 2.7V)


# Tune the lines below only if you know what you are doing:

AVRDUDE = avrdude $(PROGRAMMER) -p $(DEVICE)
COMPILE = avr-gcc -Wall -Os -DF_CPU=$(CLOCK) -mmcu=$(DEVICE)

# symbolic targets:
all:	main.hex

.c.o:
	$(COMPILE) -c $< -o $@

.S.o:
	$(COMPILE) -x assembler-with-cpp -c $< -o $@
# "-x assembler-with-cpp" should not be necessary since this is the default
# file type for the .S (with capital S) extension. However, upper case
# characters are not always preserved on Windows. To ensure WinAVR
# compatibility define the file type manually.

.c.s:
	$(COMPILE) -S $< -o $@

flash:	all
	$(AVRDUDE) -U flash:w:main.hex:i

fuse:
	$(AVRDUDE) $(FUSES)

# Xcode uses the Makefile targets "", "clean" and "install"
install: flash fuse

# if you use a bootloader, change the command below appropriately:
load: all
	bootloadHID main.hex

clean:
	rm -f main.hex main.elf $(OBJECTS)

# file targets:
main.elf: $(OBJECTS)
	$(COMPILE) -o main.elf $(OBJECTS)

main.hex: main.elf
	rm -f main.hex
	avr-objcopy -j .text -j .data -O ihex main.elf main.hex
# If you have an EEPROM section, you must also create a hex file for the
# EEPROM and add it to the "flash" target.

# Targets for code debugging and analysis:
disasm:	main.elf
	avr-objdump -d main.elf

cpp:
	$(COMPILE) -E main.c

...

You will of-course also have to edit up a uart.h with the things (eg function prototypes, extern declarations of "shared" variables etc) that needs to be seen from both main.c and uart.c and #include that file in both main.c and uart.c .

#ifndef USART_H
#define USART_H 

#include 
#include 

uint8_t uart_putchar (char data);
uint8_t uart_getchar (void);
void uart_putstring(char *s);

#endif

#include "uart.h"

uint8_t uart_putchar (char data)
{
	while ( !( UCSRA & (1<<UDRE)) ); // Wait for empty transmit buffer           
	UDR = data;  // Putting data into the buffer, forces transmission                               
	return 0;
}

uint8_t uart_getchar (void)
{
	while ( !(UCSRA & (1<<RXC)) );  // Wait for data to be received           
	return (UDR);        // Return Data                         
}

void uart_putstring(char *s)
{
	while(*s) uart_putchar(*s++);
	
} 

#include 
#include 
#include 
#include 
#include 
#include  
#include "uart.h"

Personally, when there's a lot of common system headers included in each .c I'd put the #includes in a syshdr.h and then just #include "syshdr.h" in each .c to reduce the "noise".

The use of ".h" as the extension even for nested includes is quite wide-spread.

.inc from my experience is usually reserved for includes in assembly projects.

But as Dean stated, the C compiler does not care what the extension is. #include is simply a text insertion.

You may want to take a look at in AVR-LibC ;-)

Even \Program Files\Microsoft Visual Studio\VC98\include\windows.h is little more than a bunch of #include's

So add a "-lm" to your LDFLAGS or, if using AVR Studio go into project config and under "Libraries" copy libm.a from the left to the right pane.

typedef struct
{
	uint8_t one;
	uint8_t two;
	uint8_t three;
} MyStructure;

MyStructure myStructureArray [12];

extern typedef struct MyStructure;
extern MyStructure myStructureArray [];