I am getting stared with my Photon and I cannot get the D7 LED to turn on using the Tinker app. When I connect a meter to D7 I can toggle the voltage from 3.3V to 0V, and I have the same voltage showing up on the LED pad nearest to D7. The other side of the LED is connected to ground. Looking at the data sheet for the LED (Everlight 19-217/BHC-ZL1M2RY/3T) it looks like there is a notch on one of the pads indicating cathode, which should be connected to ground. In the attached picture, it looks like the notch is where the anode should be. Would someone with a working D7 LED compare theirs to this picture? Thanks.