Hi,
I'm an Arduino newbie, I inherited a project using a Mega2560 board, and I wanted to know how the system and clock speeds/settings had been set with the fuse bits, and it isn't making much sense so far.
Using calls from avr/boot.h, the low fuse bits from:
lcd.print(boot_lock_fuse_bits_get(GET_LOW_FUSE_BITS));
..or
unsigned int low_uint = boot_lock_fuse_bits_get(GET_LOW_FUSE_BITS);
Serial.println(low_uint);
..all show "255".
This is 0xFF, or 11111111..
This implies none of the low fuse bits are programmed ("0" == programmed), which would further mean that an external clock is in use (none is connected.. and the Arduino board has a 16MHz xtal on pins XTAL1 and XTAL2).
The same test using GET_LOW_FUSE_BITS and GET_EXTENDED_FUSE_BITS returns 208 and 253, respectively, and I'm in the process of seeing if those make any sense (page 337 of Mega2560 datasheet).
Any insight is appreciated.
Bill