I loved the idea of Arduino the day I found out about it. After getting a starter kit I got myself to learn how to use it. Made several small things but never actually wanted to keep them. That was until I got inspired by a Fibonacci clock https://goo.gl/images/BhLVEJ
I am making my own version of it, a bit different, the golden ratio spiral will be there, too. Using DS3231, 5 shift registers and 37 LED diodes. Currently switching from breadboard prototype using Arduino Uno to a PCB with Nano.
My question is about the current used by this setup. Found out Nano has an absolute limit of 200ma. When time displayed is something like 11:57 almost all LED are meant to light up.
How to calculate if I am within limits?
Does changing resistors will change it? Currently using 220 Ohm and 330 Ohm on the breadboard.
Should I connect power pins of my five SN74HC595N registers to Nano’s VIN insted of 3.3v? I am thinking about using a single 18650 cell (4.2 down to 3.2 v). Do I need a voltage regulator for it? I am really afraid to give the PCB version a test.
All replies highly appreciated!