Hi!
Recently I started to build my first lightsaber. The goal is to create my own custom chassis and do the installation on my own (and break stuff and learn a ton in the process).
I need to calculate resistors for WS2812B.
I’m using proffie 3.9, Keepower battery (3.7 V).
So using LED Calculator I added 3.7 as supply voltage, 3.5 as LED Forward Voltage (as this is the minimum WS2812B can handle) and 120 mA Desired Current (there are going to be two WS2812B’s to light up crystal chamber on both ends).
Could you please give me a hand and verify if I calculate those resistors correctly?
These strips are used in many blades. You won’t have to add a resistor to the current with a proffieboard. You should have a 330/470 resistor somewhere on the data line. On the proffie, Data1 is already covered with a resistor on the board. If you need more data lines (for crystal chambers nd other blades), then there needs to be a resistor somewhere in the line. It could be on the hilt pcb, the blade pcb, or just wired end to end wherever it will fit in the chassis.
This is the wrong calculator. (And there is no “right” calculator.)
This calculator is for single bare LEDs. A WS2811 has it’s own driver circuitry for the three LEDs that are in there and don’t need resistors for the purpose of current limiting. (Which is what this calculator is for.)
There are other possibly reasons for adding resistors, such as protecting against shorts, blade ID and prevent the LED from leeching current from the data pin, but you can’t use this calculator for any of those purposes.
