Arduino Forum

Using Arduino => LEDs and Multiplexing => Topic started by: vepty on May 22, 2017, 10:10 am

Title: Hardware list confirmation for WS2812b 12x24 matrix
Post by: vepty on May 22, 2017, 10:10 am
Hi !

I want to create led matrix of 288 pixel (12x24)

I'm asking you just to confirm my hardware list, let's see :

- arduino uno r3 : amazon (https://www.amazon.fr/Elegoo-ATmega328P-ATMEGA16U2-Compatible-Arduino/dp/B01N91PVIS/ref=cm_cr_arp_d_product_top?ie=UTF8)
- WS2812B Pre-wired LED (x6) : ebay (http://www.ebay.com/itm/50Pcs-WS2812B-Pre-wired-LED-Pixel-Module-String-Light-Color-5050-SMD-RGB-DC5V-/232059694439?hash=item3607d5ed67:g:740AAOSwU-pXvtt3)
- DC 5V 20A : amazon (https://www.amazon.fr/Transformateur-Tension-interrupteur-commutateur-dalimentation/dp/B01HO0TDB0/ref=sr_1_1?ie=UTF8&qid=1495376413&sr=8-1&keywords=alimentation+5v+20a)

And just 2 questions :

I saw in few tutorials that some people used resistor in the data line, and a capacitor parallel across the power supply. Do I have to do this ? why ? And if yes, how much ohm for resistor and which capacitance for capacitor ?

Thanks to all !
Title: Re: Hardware list confirmation for WS2812b 12x24 matrix
Post by: Grumpy_Mike on May 22, 2017, 01:42 pm
Quote
I saw in few tutorials that some people used resistor in the data line, and a capacitor parallel across the power supply. Do I have to do this ?
Yes.

Quote
how much ohm for resistor and which capacitance for capacitor ?
Between 220 and 470R not very critical but it helps damp down reflections and ringing, see the trace attached.
Capacitor at least 470uF and with such a big matrix I would put one at both ends of the power chain at least.

(https://forum.arduino.cc/index.php?action=dlattach;topic=478877.0;attach=212828)
Title: Re: Hardware list confirmation for WS2812b 12x24 matrix
Post by: vepty on May 22, 2017, 02:22 pm
Thank you for explainations Grumpy_Mike :-)

What do you think about hardware that I choosed ?

 
Title: Re: Hardware list confirmation for WS2812b 12x24 matrix
Post by: Grumpy_Mike on May 22, 2017, 06:14 pm
Well the Arduino is a fake and I haven't had experience of the LEDs and power supplies so I can't say one way or the other, but nothing springs out looking at the links.