“The timer is a tool often used in both industrial and household activities.
This assembly is cheap and easy to make.
It is also very versatile, being able to load a program chosen according to needs. There are several programs written by me, for Arduino Nano.
The duration of the timer can be entered on the display (1602) from the rotary encoder. By pressing the button on the rotary encoder the timer is triggered.The load will be powered during the time delay via the contacts of a relay.
I personally used the timer for UV exposure in the process of PCB, but also at home where a kitchen robot operated to knead bread dough.
Supplies:All components can be found on AliExpress at low prices.
PCB is designed and manufactured by me (KiCad project). The method of PCB production will be the subject of a future Instructables.”