Mcu works from 8MHz internal oscillator. But you should use external qrystal oscillator for more stability!
Source code written on C language in Atmel Studio 7 IDE.
For flashing MCU I used AVR ISP USBasp programmer and desktop app khazama
You should set Fuse bits only for change oscillators source (internal 8MHz or external 8MHz)! Leave the remaining bits at default!
If you use an internal generator, remove C3, C4 and Y1 from circuit
R2 resistor needed to adjust contrast of LCD
Device soldered on solder breadboard and put on KRADEX Z70 Housing case
Device circuit diagramm:
