ESP8266 Community Forum

- Sat Nov 05, 2016 10:36 am #57700 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!

- Sun Nov 06, 2016 3:26 am #57725 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/

- Sun Nov 06, 2016 3:59 am #57726 If you need only ON/OFF for your LED's then a port expander solution like the PCF8575 one from here is enough.



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



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

ESP8266 MPDMv4 AC MAINS Dimmer Home: http://esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch-html/
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/

- Sun Nov 06, 2016 7:52 am #57735 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.