design is built around the WeAct Studios "Blackpill" w/STM32F411CE processor (available on eBay, Aliexpress, etc.) It has 512KB of flash, runs at 100MHz, and has a floating point unit for fast performace. This has a moderate amount of soldering necessary but most components needed to build one of these can be obtained from EasyEDA/LCSC and eBay. **Note: This design is for non-commercial use only (see License terms, CC-BY-NC-SA 3.0)** This controller includes the following features: * Power: Coaxial power jack, fuse, and power switch connection. * Stepper drivers: Four, one for RA/Azm, one for Dec/Alt, one for a focuser, and one for a rotator/second focuser. It's designed for TMC2130 or TMC5160 drivers (only) in all four sockets. All stepper motor connections are available on RJ jacks at the PCB back (screw terminals are optional.) * Needs a DS3231 RTC Module with AT24C32 4KB EEPROM to function (eBay etc.) * WiFi or Ethernet: WeMos D1 Mini ESP8266 foot-print (uses Serial2.) * Micro USB port built into the Teensy4.1. * Mini speaker for alert buzzer. * DB15 15 pin D-Sub connector: primary external I/O for Gnd, +3.3V, 5V, two Home Switches, PEC, PPS, I2C, the Serial1 port, and two channels of A/B encoder inputs. * 3.5mm stereo mini jack: secondary external I/O for Limit Switches and Reticle. * RJ12 Modular connector: ST4 guider interface (with optional 5V power.) History - Version3.6 - First release