No, no, no, I didn't mean for you to RTFM...this time I was only pointing it out, making sure.
I think I would set it up with a 'stock' combo when you program it set up in eeprom, say 12345 (that's amazing, I've got the same combination on my luggage!)...
Then, there's one sequence of numbers that only you know and will never tell anybody (call it a 'back door')...say, 1234567890.. If you get that sequence, the system knows that the next 5 numbers input will be the new combination and you have to enter them twice. Then save those new 5 numbers in the eeprom (read, write), and BAM the combo is changed.
Bookmarks