scharkalvin
Member
The back side of the Teensy 4 has several round pads that are not labeled on the schematic or the color pin drawing. There are 4 such pads between the rectangular pads for "pins" 24-33, another one just to the right side of pads 27 and 29, and two more near the USB host pads and pads 34-39. What are these for? I am guessing that three of them are for an SWD debugger, but this is not seen on the schematic.