What is the solder jumper on the bottom of the ItsyBitsy M4?

[michaelmeissner]

If you look on the back of the ItsyBitsy M4 PCB, there is a solder jumper between two pads. This jumper is next to the AREF and VHI pins. The solder jumper is normally connected when you buy the ItsyBitsy M4. None of the other ItsyBitsy's seem to have this.

In looking at the schematics, I believe that when the solder pads are connected, it normally connects the AREF pin to 3.3 volts. What happens if you cut the solder trace? Is the AREF pin now floating, or is it connected to another pin?

[adafruit_support_bill]

If you cut the jumper, you can connect an external analog reference voltage to the Aref pin (<= 3.3v) and select the external analog reference in your code.

[michaelmeissner]

Thanks.