the JD-VCC/VCC jumper is on the board (i don’t really know what it does) but it can’t be placed on 2 other pins, what i mean by that is that there are only 2 pin headers on the board, so i can put it on or off.
And the arduino and relay share the same ground (the Arduino is powered by the same source).
Its wired to pins 30, 31, 33 and 34. 5V to VCC and GND to GND of course.
Isaak