avrdude

Program AVR microcontroller flash and fuses

TLDR

Upload firmware to Arduino

$ avrdude -p [atmega328p] -c [arduino] -P [/dev/ttyUSB0] -U flash:w:[firmware.hex]

Read flash memory

$ avrdude -p [atmega328p] -c [usbasp] -U flash:r:[backup.hex]:i

Set fuse bits

$ avrdude -p [atmega328p] -c [usbasp] -U lfuse:w:[0xE2]:m

Verify without writing

$ avrdude -p [atmega328p] -c [arduino] -P [/dev/ttyUSB0] -U flash:v:[firmware.hex]

SYNOPSIS

avrdude -p partno -c programmer [options]

avrdude (AVR Downloader Uploader) is a utility for programming Atmel AVR microcontrollers. It supports numerous programmers and can read/write flash, EEPROM, fuse bits, and lock bits.
The tool is essential for Arduino development and embedded systems work with AVR chips.

PARAMETERS

-p partno

Specify AVR device (e.g., atmega328p, attiny85)

-c programmer

Programmer type (arduino, usbasp, avrisp2)

-P port

Communication port (/dev/ttyUSB0, COM3)

-U memtype:op:file:format

Memory operation (flash:w:file.hex:i)

-b baudrate

Override baud rate

-B bitclock

Bit clock period

-v

Verbose output

-n

Dry run (no writes)

-F

Force (override signature check)

CONFIGURATION

/etc/avrdude.conf

System-wide configuration defining programmer types, part definitions, and default settings.

~/.avrduderc

Per-user configuration overrides. Can add custom programmer definitions or modify part settings.

MEMORY OPERATIONS

flash

Program memory

eeprom

Data memory

lfuse, hfuse, efuse

Configuration fuses

lock

Lock bits

Operations: r (read), w (write), v (verify)

CAVEATS

Incorrect fuse settings can brick the device. Requires proper permissions for serial ports. Wrong programmer selection causes failures. Always backup fuses before modification. USB connection issues common on some platforms.

HISTORY

avrdude was created by Brian Dean in 2003 as an open-source alternative to Atmel's proprietary programming tools. It has become the standard tool for AVR programming.