Programming Arduino from terminal

Projects Programming
1

Hi,
I'm experimenting with an Arduino Uno R3 and a MacBook. I want to compile and load a code via terminal, so, I go in the Arduino folder and I search for avr-gcc and avrdude.
I compile using avr-gcc a very simple Blink program that turns on and off a LED, and I get the hex file with no errors or warnings.
Then I run in the terminal (from the Arduino.app/Contents/Resources/Java/hardware/tools/avr/ folder)

./bin/avrdude -C ./etc/avrdude.conf -p m328p -c arduino -P /dev/tty.usbmodem641 samplecode.hex

To push the hex file into the Arduino, and I get the following output

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e950f

avrdude: safemode: Fuses OK

avrdude done.  Thank you.

It seems that everything is ok, but the led doesn't blink, so the code has not been loaded on the Arduino. I double checked the code to be sure that's not a code problem. The avrdude configuration file is from the arduino IDE, so it should work. I think the problem is the programmer, but I don't know, maybe the problem is somewhere else.
Oh, and, if you know, is there a way to use Arduino as ISP via terminal?

Thank you in advance

2

It seems that everything is ok, but the led doesn't blink, so the code has not been loaded on the Arduino.

I can't see how you jump all the way to the conclusion that avrdude is faulty. Your (un posted code however ....)

Mark

3

Here is the test code, it is very simple, I don't think the problem it this

#define F_CPU 16000000
#define __AVR_ATmega328P__

#include <avr/io.h>
#include <util/delay.h>

void setup() {
    DDRB |= _BV(PINB5); // set pin 13 as output
}

void loop() {
    PORTB |= _BV(PINB5);
    _delay_ms(500);
    PORTB &= ~_BV(PINB5);
    _delay_ms(500);
}

compiled with:

avr-gcc -O2 -o samplecode.hex samplecode.c
4

Where is main.c how did you link it? looks like you may have an empty .hex

Mark

5

No, the hex file is 2.0Kb, it is not empty.
I was using an avr-gcc downloaded from the internet that maybe adds automatically the main().
However I deleted it, and using the avr-gcc inside the arduino I had to rewrite the code:

#define F_CPU 16000000
#define __AVR_ATmega328P__

#include <avr/io.h>
#include <util/delay.h>

void loop(void);
void setup(void);

int main() {
    setup();
    while(1)
        loop();
}

void setup(void) {
    DDRB |= _BV(PINB5); // set pin 13 as output
}

void loop(void) {
    PORTB |= _BV(PINB5);
    _delay_ms(500);
    PORTB &= ~_BV(PINB5);
    _delay_ms(500);
}

However reading the avrdude manual I discovered that the avrdude command I typed is wrong, because it doesn't write nothing on the Arduino. The right command is this:

avrdude -C [optional, path of avrdude.conf] -p m328p -c arduino -P /dev/tty.usbmodem641 -e -U flash:w:"./samplecode.hex"
6 
-U flash:w:"./samplecode.hex"

hah! Yes; you figured it out before I got around to answering!
So is everything working now?

7

Now running the same avrdude command I get this error:

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e950f
avrdude: erasing chip
avrdude: reading input file "./test.hex"
avrdude: input file ./test.hex auto detected as invalid format
avrdude: invalid input file format: -1
avrdude: read from file './test.hex' failed

avrdude: safemode: Fuses OK

avrdude done.  Thank you.

but if I compile with --mmcu=atmega328p I don't get that error, but my code seems to not work. It should switch on a led connected on pin 4. Here is my test code

#ifndef __AVR_ATmega328P__ 
    #define __AVR_ATmega328P__  // microcontroller
#endif
#define F_CPU 16000000      // frequency of the cpu

#include <avr/io.h>
//#include <avr/interrupt.h>
#include <util/delay.h>
#include <util/atomic.h>

int main() {
    DDRD = _BV(PIND4); // pin 4
    PORTD = _BV(PIND4);

    while (1) {
        _delay_ms(1000);
        PORTD = _BV(PIND4);
    }
    
    return 0;
}
8 
avr-gcc -O2 -o samplecode.hex samplecode.c

avr-gcc does not produce .hex files, it produces elf format files which you would then convert to .hex files with "avr-objcopy" Something like:

 avr-objcopy -O ihex -R .eeprom a.out float.hex

Being a "well behaved" unix-style program, avr-gcc will happily and silently allow you to name the elf file with a .hex "type", even though the format is entirely different.