We have made another update of the Hackerbus white paper, with the following changes:

- GPIO_d now uses configurable VAUX3 as supply, not a fixed 2.7 V rail

- Documented alternative Hackerbus pin assignment

Link to the latest version of the document:

http://neo900.org/stuff/papers/hb.pdf

This specific version is at
http://neo900.org/stuff/papers/hb-20161121.pdf

The source can be found at
https://neo900.org/git/misc/tree/hb

As always, comments are welcome.

- Werner