She held off Slovenia's Tina Maze by just a single point after bad fog forced the abandonment of the season's final downhill race in Lenzerheide in Switzerland on Wednesday.
Going into the final event, Vonn led the standings with 340 points despite missing the preceding races at Meribel and Garmisch, with Maze right behind her.
The PCB is attached to the watch with a maze of wires, and allows the team to prototype new software and debug the system before commissioning the final miniature board that will go inside the shipping product.