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Interface about 24 LEDs to an ESP-12E

PostPosted: Sat Nov 05, 2016 10:36 am
by hussainb
Hello,

I would like to control around 24 independent LEDs from an ESP.
I do not want to use an LED matrix module since the positions of the LEDs are not in a grid/matrix and I will be placing them at different locations on my model.

I would like to know what options I have to do the same.

Right now, I have thought about using a multiplexer to control the number of LEDs, but I am not sure if the multiplexer will be able to simultaneously light up more than one LED at the same time, and if it would meet the voltage and current requirements.

If the multiplexer is the only way to achieve this, It would be helpful if someone can provide with a schematic and part numbers to implement this.

I am open to suggestions on different mechanisms to interface the LEDs.

Thanks!

Re: Interface about 24 LEDs to an ESP-12E

PostPosted: Sun Nov 06, 2016 3:26 am
by Barnabybear
Hi, whilst there are many ways you could do this a port expander makes life easy. Have a look at this:
http://tronixstuff.com/2011/08/26/tutor ... -io-ports/

Re: Interface about 24 LEDs to an ESP-12E

PostPosted: Sun Nov 06, 2016 3:59 am
by trackerj
If you need only ON/OFF for your LED's then a port expander solution like the PCF8575 one from here is enough.

Image

If you want to be able also to do LED dimming a 16Channels PWM Extension Board is what do you want to use:

Image

You can find them also available on Tindie Store for about 5USD

Re: Interface about 24 LEDs to an ESP-12E

PostPosted: Sun Nov 06, 2016 7:52 am
by hussainb
Dont know why my earlier reply didn't show up.

Anyways..

Thankyou Barnabybear and trackerj for the suggestion. I really wasn't aware of a port expander.

But right now I am confused. which one should I prefer, The PCF8575 or MCP23017?

I found an instructable here: http://www.instructables.com/id/Using-The-PCF8575-i2c-io-Expander-To-Read-Inputs-/ In which it is said that the MCP23017 doesn't need resistors to read inputs from a push button.