What follows are preliminary notes during the build of the KRZ03, a Mechanum-wheeled robot. It uses parts from the KRZ01 and KRZ02 robots and therefore supercedes (replaces) them. Its Raspberry Pi Zero W, Mini Black Hat Hack3r, and a pair of Picon Zero motor controllers were used on the KRZ02. After contacting 4Tronix, they sent a customised Picon Zero that uses a different I2C address so that it's possible to use two on this robot without bus contention. A simpler alternative would have been to use the PiBorg ZeroBorg Motor ControllerContent unavailable! (broken link)https://service.robots.org.nz/wiki/images/out.png, which has four motor controllers as well as a 1.5A regulated power supply.