DB15Exp-ABD

Port expansion for the DB15 connector of my Max series controllers version 3.6 or 4.x.  The PCB is sized to fit within the plastic shell of one of these.

This has a pair (Axis1 and Axis2) of differiental signaling inputs to carry A/B quadrature signaling from encoders.  It also has level conversion so the encoder input pins going to OnStep's Smart Web Server are 3.3V level.

Additionally there are connections (most can be used for other purposes too) for:

• Ground, 3.3V, 5V.
• A BME280 Weather sensor if you want that onboard (or for extending the I2C bus if desired.)
• A TTL Serial bus (or other purposes.)
• A PEC input.
• A pair of home switches (Axis1 and Axis2.)
• A spare GPIO (general purpose for 1-Wire, PPS, etc.)