CodeLockAVR electronic combination lock is realised with

Atmel AVR microcontroller AT90S2313. Program in hex code is

2 kB long. User code is consisted of 1 to 4 digits.

If the code is entered in the correct sequence, then after 1 second

the relay and the electric striker (in the door) switch on for 1

second and then switch off again.

User code can be changed via 3x4 matrix keypad. Keypad can be

bought at local electronic shop.

Initial user code (1234) is set up with a jumper. The jumper must

be inserted before the voltage (12V) connection. The jumper must

be removed after 2 beeps.