This expansion board, as a driver expansion board, can be used for engraving machines, 3D printers. It is a total of four slots, can drive four A4988 stepper motors. Each road stepper motor only needs two IO ports. In other words, six IO ports can be well managed with three stepper motors. It is very convenient to use.
Features:
Expanded board to add a 4th axis that can duplicate the X, Y or Z axes. With a 4th option to use pin D12-13 to control it.
Added a discussion header for all Axes.
Added communication header for UART (Serail) and I2C
Added a connector for an optional fuse (the fuse is not powered because it must be selected for the current used).
The capacitors are mounted horizontally, which gives more space between them and the stepper motors. Good for ventilation.
Added a pull-up resistor on the axis enable pins. This prevents the pin from being in a floating state
Added 2 mounting holes
