I soldered a 2X5 pin header (from Sparkfun) to my SparkFun SAMD21 Mini Breakout board. I also have the .pdf file at:
https://cdn.sparkfun.com/assets/learn_t … t-Mini.pdf
I saw the vertical bar next the bottom left corner pin as viewed from the .pdf graphic of the header position. Is this pin 1 VCC?