ESP8266 Community Forum

- Tue Feb 28, 2017 8:26 pm #63162 I've noticed I can't use certain IOpins when running the WEMOS D1 mini, esp8266.
When I run the simple LED blink example which blinks TX pin. Pin D4/2 is taken up and blinks the reverse of TX, like is on when TX is off and vice versa. Why is this?

- Wed Mar 01, 2017 10:08 am #63184 It is all depend how LED is connected, in source mode or in sink mode.

- Wed Mar 01, 2017 1:01 pm #63192 On = 1, a low signal. High is off, 1. The TX led is connected as in the second way shown above.