I noticed on the Grids Open Source section, with respect to flashing a new firmware:
“The ISP programmer must be connected on the back of the module – red stripe of the cable on the same side as the ISP text on the board.”
The red stripe of the ISP cable is usually used to denote pin 1, as far as I know. However, as far as I can tell from the schematic, pin 1 of the ISP header is on the opposite side from the ‘ISP’ silk screen on the board. I may of course be wrong here…