I am new to electronics and I want to try an experiment.
I want to use a 555 timer to create an automatic food dispenser for my aquarium (something like opening a small door when the timer has elapsed) and I need some help in timing here.
To have a configurable amount of time (lets say 6 hrs, 12 hrs or 24 hrs), I understand that I need to modify resistors and capacitors accordingly.
Can you please let me know if there is any standard formula or tool for calculating the resistance value required for my resistors and the capacitance value required for my capacitors in my experiment.
Note: If I am completely wrong with my approach, please let me know a better way for creating an automatic timer. I am completely new to electronics and just got this basic info over the net.