View source for Arduino: How to modify fuses

=== Read fuses from Atmel mcpu ===
Following command read Low/High/Extended fuse configuration from mcpu + lock configuration:
<pre>
avrdude -p m328p -c dragon_isp -P usb -U lfuse:r:-:h -U hfuse:r:-:h -U efuse:r:-:h -U lock:r:-:h
</pre>
=== "Program" fuses ===
Following command set Low/High/Extended fuse and lock configuration (default configuration for Arduino UNO board):
<pre>
avrdude -p m328p -c dragon_isp -P usb -u -U lfuse:w:0xff:m -U hfuse:w:0xde:m -U efuse:w:0x05:m -U lock:w:0x3f:m
</pre>
''Note: fuses are stored in eeprom memory. Due to HW restriction clearing memory set each cell to 0xFF. Therefore "unprogrammed" fuse have value of "1".''

=== Default fuses (Arduino UNO) ===
<pre>
lfuse: 0xff
hfuse: 0xde
efuse: 0x05
lock:  0x3f
</pre>