Hi, I'm new to arduino but excited to explore possibilities!
I'm trying to add internal lights to a scale model I've built and so I've got a range of LEDs from standard 5V LED strips (of a single colour) to individual LEDs, some flashing in sync, others executing a sequence controlled by an Arduino UNO. Among the lights is 5 strips of WS2812B which will also be controlled by the Arduino UNO. I'm trying to work out how i will power the system as i know that the UNO has certain power limits and the one question mark I have still is how much current does the Data IN pin to control a WS2812B strip consume?
I know these are the UNO limitations:
I/O pins absolute max 40mA, ideally run at around 20mA per pin
I/O pins must not draw more than 200mA absolute maximum across all pins
And that here are my requirements for those LEDs that will need some control by the Arduino UNO:
2 x bi-colour LEDs (only one colour per LED on at a given time) = 2 x 20mA = 40mA
5 x blinking individual LEDs = 5 x 20mA = 100mA
5 x WS2812B strips of 14 cells each = max. 5 x 14 x 60 = 4.2A
So I think I'm ok to power and thereby control all of the normal LEDs directly from the UNO's digital I/O pins as long as I power the WS2812Bs externally but control them through the UNO.
Therefore I need to know how much current does each data line consume per ws2812b strip so as to know if I am still below the UNO's total current limit. I realise this may be a stupid question but I can't seem to find anything about it in the product details or online (probably I'm sure because it is a stupid question). I assume 5V will be the output from the PWM pin on the arduino and that if i add a resistor before the first LED on the data line this will change the current? But without the resistor what is the current, is there a way of calculating it?