I recently bought a Wemos D1 board and tried to connect a relay and test its connection.
I got an example server from here and executed. I connected D5 to a Relay's data and 5v and GND from Wemos board.
But this does not change the state of relay, it always remains high. I connected a LED for D5, it works perfectly with client's response.
Then I powered relay using an external 5v and ground connection, but the same result.
I have checked for possible solution, but coulnt find an answer.
The relay I am using is this one