Arduino Forum

Using Arduino => LEDs and Multiplexing => Topic started by: DeXan74 on Jan 22, 2018, 12:44 pm

Title: 2 power supplies with ws2812b?
Post by: DeXan74 on Jan 22, 2018, 12:44 pm
Hi all,
So after many hours reading and searching I would like a definitive answer for my simple(?) wiring set up please.
I have an Arduino UNO R3 with 2 x WS2812b strips of 30l/m.

I am making two arch strips with 86 leds each. Total = 172 leds
Each strip will be controlled separately (using Pin 12 and Pin 13).
My initial calculations are as follows and I am happy with this so far (with some more tweaking).

Full bright(256) = 60ma * 172 = 10.3 amps (I will not use all white so this is worse case...)

I will reduce brightness to 100 in my code, 100/256 * 60 *172 =  4.03amps

My issue is do I want them powered separately using 2 x 5volt 4amp power supplies, or just use one in the centre of my project. I would like to consider both wiring options please.


I know we need to tie the grounds, but do I just join ALL the ground wires to each other and the Arduino?
Does this interfere with the Data of the separate strips somehow?


My Diagram shows 2 power supplies - it is only my starting point.
Cheers,
DeXan

Title: Re: 2 power supplies with ws2812b?
Post by: larryd on Jan 22, 2018, 07:21 pm
(http://forum.arduino.cc/index.php?action=dlattach;topic=524186.0;attach=242304)

Quote
I know we need to tie the grounds,
Then why isn't the top GND commoned?


Title: Re: 2 power supplies with ws2812b?
Post by: DeXan74 on Jan 22, 2018, 11:15 pm
I tried once and blew the first LED, so I was wondering if the Data line would be OK if I did this.

Is this (updated) diagram all we need to do to safely achieve this goal?

Thanks.


Title: Re: 2 power supplies with ws2812b?
Post by: Grumpy_Mike on Jan 22, 2018, 11:19 pm
Quote
I tried once and blew the first LED,
Then something else was wrong.

Quote
so I was wondering if the Data line would be OK if I did this.
No it is not.