12axis Flex Module

Somehow, I reversed the i2c pins on the 2 layer. So I will fix that before selling them. I still can't decide if the 2 layer or slightly smaller 4 layer design is better.

We have found better performance in 2 layers, though the 4 layer boards do work OK. We might be able to determine the 4 layer issues, but I think it might come down to quality of solder mask. The 9 axis has some tiny pads, and for some reason the 4 layer quality just isn't there.

I think having 4 layers has complicated things. I am having serious issues communicating with the chips. So I am reducing the layers, spreading the chips further apart, and minimizing the amount of traces under the components. I hope to see a serious improvement.

Increasing size for easy hand soldering. Rearranged i2c bus similar to other Flex Module designs.

Similar to the original 10-axis design. I have already sent the boards to be made by OSHPark.