DRV8838 Breakout board from below

GND     GND
VIN     VCC
O2      EN
O1      PH
VM      SLP

GND pins are marked with quadratic (as opposed to round) pins

View from above

GND VIN O2  O1 VM


GND VCC EN  PH SLP

WARNING: The VCC in the datasheet and the VCC in the Pollolu
breakout-board are different!

VCC is the logic supply voltage         1.8-7 V
VIN is the supply voltage for the motor 0-11  V