Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By martinayotte
#34894 On which GPIO are you placing your LED ?
Because if you place a LED on GPIO2 or GPIO0 to GND, it is acting like a pull-down, preventing to boot in execute mode.
For those pins, you need to reverse the LED polarity thru VCC, and in the software the polarity will be reverse too, LOW will make the LED turn On.
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By Venkatesh
#34896 Try to reverse it
(1) Connect LED (-) to GPIO2 and LED (+) to Vcc (3.3v) with 220R.
(2) Connect a 3K3 or more resistor between GPIO 2 and Vcc (3.3v), this should be parallel to led connection.

Now in code, use LOW to turn led on and HIGH to turn it off.