AVR: Compile and Upload Code#

Toolchain Overview#

To compile and upload code to an AVR microcontroller, you’ll need the AVR-GCC toolchain. This includes essential components such as the compiler, assembler, linker, and utilities like avr-objcopy.

Installation#

You can download and install the AVR-GCC toolchain from the official Microchip website:

Download the installer from the Microchip website and follow the installation instructions.

AVR-GCC Compiler for Microchip Studio

You can install the AVR-GCC toolchain using your package manager. For example, on Ubuntu:

sudo apt-get install avr-gcc avr-binutils avr-libc

You can use Homebrew to install the AVR-GCC toolchain:

brew tap osx-cross/avr
brew install avr-gcc

Ensure the toolchain is added to your system’s PATH environment variable for global access.

Example: Compiling a Blink Program#

This example demonstrates how to compile a basic blink program for two common AVR microcontrollers:

ATtiny88
ATmega328P

         +-----------------+
PC6 (RST)| 1  ATmega328 28 | PC5 (A5)
PD0 (RX) | 2            27 | PC4 (A4)
PD1 (TX) | 3            26 | PC3 (A3)
     PD2 | 4            25 | PC2 (A2)
PD3 (PWM)| 5            24 | PC1 (A1)
     PD4 | 6            23 | PC0 (A0)
    VCC  | 7            22 | GND
    GND  | 8            21 | AREF
     PB6 | 9            20 | AVCC
     PB7 |10            19 | PB5 (D13)
PD5 (D5) |11            18 | PB4 (D12)
PD6 (D6) |12            17 | PB3 (D11/PWM)
PD7 (D7) |13            16 | PB2 (D10/PWM)
PB0 (D8) |14            15 | PB1 (D9/PWM)
         +-----------------+

The program toggles an LED connected to pin PB0 every second.

Source File#

#define F_CPU 16000000UL
#include <avr/io.h>
#include <util/delay.h>

int main(void) {
    DDRB |= (1 << PB0); // Set PB0 as output
    while (1) {
        PORTB ^= (1 << PB0); // Toggle PB0
        _delay_ms(1000);
    }
}

Compilation Commands#

Use the following commands to compile and generate the HEX file:

# For ATtiny88
avr-gcc -mmcu=attiny88 -Os -o blink.elf blink.c
avr-objcopy -O ihex blink.elf blink.hex

# For ATmega328P
avr-gcc -mmcu=atmega328p -DF_CPU=16000000UL -Os -o blink.elf blink.c
avr-objcopy -O ihex blink.elf blink.hex

Explanation of flags:

-mmcu= specifies the target microcontroller.
-Os enables size optimization.
-DF_CPU sets the clock frequency used for timing functions.

Uploading with AVRDUDE#

Once the .hex file is generated, you can upload it to the AVR microcontroller using AVRDUDE.

Installation AVRDUDE Linux#

You can install AVRDUDE on Linux using your package manager. For example, on Ubuntu:

sudo apt-get install avrdude

Upload Command#

avrdude -p m328p -c usbasp -U flash:w:blink.hex

Explanation:

-p m328p specifies the target device (ATmega328P).
-c usbasp sets the programmer to the CH552 USB Multi-Protocol Programmer.
-U flash:w:blink.hex uploads the hex file to flash memory.

Replace m328p with the appropriate identifier for your specific AVR device (e.g., t88 for ATtiny88). A full list of supported devices is available in the AVRDUDE user manual.

ATMEGA328P Microcontroller

AVR: Compile and Upload Code

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