Programming AVR - Parallel Port (LPT)

Here is a quick and dirty tutorial for writing data and setting fuse bits on an AVR microcontroler using Ubuntu. All details in this post are related to the Atmega8-16PU, for other versions you should relate to the data sheets for the relevant specifications. First we need to get the necessary development tools:

# sudo  apt-get install gcc-avr avr-libc gdb-avr avrdude

Now we need to create a cable to go between the LPT port on your PC and the AVR micro-controller:

DB25 Male	AVR
Pin 1	SCK
Pin 2	MOSI
Pin 11	MISO
Pin 16	RESET
Pin 21	GND

*Warning: The data pins (1,2) should have a 1k resister in line, this is to stop you from killing either your LPT port, AVR, or both. It will work without just make sure you have it wired 100% correct. Run the following to test the connection:

# sudo avrdude -p m8 -P /dev/parport0 -c dapa

You should receive back:

avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9307
avrdude: safemode: Fuses OK
avrdude done.  Thank you.

If you receive:

avrdude: AVR device not responding
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.

Then something is wrong and you should check all your connections. Now to Test out some code you can try this example:

/*
 * blink.c
 */

#include <avr/io.h>
#include <util/delay.h>
#define LED PD4

int main(void) {
  // define pd4 as output
  DDRD |= (1 << LED);
  while (1) {
    PORTD |= (1 << LED);    // switch on
    _delay_ms(1000);
    PORTD &= ~(1 << LED);    // switch off
    _delay_ms(1000);
  }
return 0;
}

Save as blink.c Now in the same directory save the following Makefile:

MCU=atmega8
AVRDUDEMCU=m8
CC=/usr/bin/avr-gcc
CFLAGS=-g -Os -Wall -mcall-prologues -mmcu=$(MCU)
OBJ2HEX=/usr/bin/avr-objcopy
AVRDUDE=/usr/bin/avrdude
TARGET=blink

program : $(TARGET).hex
	$(AVRDUDE) -p $(AVRDUDEMCU) -P /dev/parport0 -c dapa -U flash:w:$(TARGET).hex

%.obj : %.o
	$(CC) $(CFLAGS) $< -o $@

%.hex : %.obj
	$(OBJ2HEX) -R .eeprom -O ihex $< $@

clean :
	rm -f *.hex *.obj *.o

So now using the makefile we are going to create a .hex file of the c code above and write it onto our chip:

# sudo make

sucessful output:

/usr/bin/avr-gcc -g -Os -Wall -mcall-prologues -mmcu=atmega8   -c -o blink.o blink.c
/usr/bin/avr-gcc -g -Os -Wall -mcall-prologues -mmcu=atmega8 blink.o -o blink.obj
/usr/bin/avr-objcopy -R .eeprom -O ihex blink.obj blink.hex
/usr/bin/avrdude -p m8 -P /dev/parport0 -c dapa -U flash:w:blink.hex

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9307
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 "blink.hex"
avrdude: input file blink.hex auto detected as Intel Hex
avrdude: writing flash (138 bytes):
Writing | ################################################## | 100% 0.05s
avrdude: 138 bytes of flash written
avrdude: verifying flash memory against blink.hex:
avrdude: load data flash data from input file blink.hex:
avrdude: input file blink.hex auto detected as Intel Hex
avrdude: input file blink.hex contains 138 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 0.03s
avrdude: verifying ...
avrdude: 138 bytes of flash verified
avrdude: safemode: Fuses OK
avrdude done.  Thank you.

rm blink.obj blink.o

Attach a LED to PD4 with a resister in line and the LED should light up and flash. Written by: Jason Smith