Use of WEMOS D8 pin (GPIO15)

Essentially I want to connect a pushbutton to the D8 pin of a WEMOS D1R2, if possible without a resistor. I could use a different pin for the button, but then I need to use it to enable/disable a A2899 and I am not sure if that would interfere with the startup of the board (see below).

If I connect it to GND and, e.g. D7 and use pinmode(7,INPUT_PULLUP) everything works as expected. D8... not.

The D8 pin is described as "I/O, 10k pull-down, SS GPIO15" (Wemos ESP8266 D1 R2 V2.1.0 Dev Board (Arduino UNO Board Footprint)), but the only restriction seems to be that it must be low at startup.

Anybody can tell me how to use that pin?

Thanks,

Paai

If your switch is a normally open momentary switch you could wire one side to Vcc and the other to pin 15. The internal pull down will keep pin 15 LOW during reset. After reset, pressing the button will pull pin 15 HIGH.

Works. Thanks. Suspected something like that, but did not want to blow up that pin.