ESP8266 Community Forum

Hi folks,

I am currently creating a sensor device (in a little box) using the esp-12 and I wanted to have a visible led that blinks when there is some activity going on. Actually, exactly like the internal blue led. Now, I already have almost all my gpios in use so I thought: wouldn't it be possible to attach a bigger led to the onboard blue led?

Could that work and how would I have to connect it?

Kind regards,
Danny

I believe that the on board blue led may be connected to the TX pin, thus adding an additional led should be a simple matter. I will put this to the test and let you know how I get on.

dannybloe wrote:I am currently creating a sensor device (in a little box) using the esp-12 and I wanted to have a visible led that blinks when there is some activity going on. Actually, exactly like the internal blue led. Now, I already have almost all my gpios in use so I thought: wouldn't it be possible to attach a bigger led to the onboard blue led?

Could that work and how would I have to connect it?

You could design your enclosure so that the blue LED lines up with a hole in the cabinet, then use a clear plastic rod stuck in the hole to 'conduct' the light out.

Or you could desolder the existing blue surface-mount LED and simply connect a bigger blue LED on some short leads. Don't make those leads too long, the ESP8266 seems to be touchy about induced interference.

So in short, yes it works as described. If another led is connected between TX and +3.3v with an appropriate resistor it will flash in time with the blue led. Keep in mind however that with 2x leds depending on the combined current draw you may be exceeding the capacity of the TX pin.