MicroPCB

This design is built around the Teensy4.0 and supports the most important features while keeping the same small size and nearly identical layout to the MiniPCB v1.x.

There's a power jack, fuse, and power switch connection.
There's a limit sense input (to stop the mount,) PEC sensor input, reticle and status LED's.
There's a USB Port and one other device supported.
There's provision for an ESP-M3 ESP8285 device for WiFi, this gets firmware uploaded through the Teensy4.0.
There's a modular connector for an ST4 guider interface with optional 5V power (and optional ESD protection using a diode clamp device.)
There's two stepper drivers (one for RA/Azm and one for Dec/Alt.)

Unlike the MiniPCBv1.x this device doesn't have a provision for Bluetooth onboard but it adds the following new features:

Supports nearly any StepStick driver including Legacy, TMC-SPI, and TMC-UART.
Uses JST-XH2.54 connectors where appropriate.
Supports I2C and has onboard provision for FRAM NV memory.
Onboard mini speaker.
Optional - Connections for status LED (Aux0) and reticle LED (Aux8) are designed so each can have Gnd, Signal, and 3.3V for general purpose use.
Optional - ST4 port connections can be used for other purposes as hardware serial and CAN interfaces are present.
Optional - Step and Dir connections on both Axis1 and Axis2 have PWM capability for DC servo operation.

This strives for drop-in compatibility with my prior OnStep Mini 1.x and earlier versions so the 3D printed case/panels *should* still more or less work (one mounting hole was moved.)

[1]: https://groups.io/g/onstep