Descriptions 1 CNC Shield V3 3D Printer Expansion BoardThis 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 motor Each road stepper motors only need two IO ports In other words six IO ports can be well managed three stepper motors Very convenient to use UNO formodule IO port correspondence introduction More info please click here 2 A4988 Reprap Step motor driver moduleSimple step and direction control interfaceShort to ground and shorted load protectionFive different step resolutions full step half step quarter step eighth step and sixteenth stepIntelligent chopping control that automatically selects the correct current decay mode fast decay or slow decay Over temperature thermal shutdown under voltage lockout and crossover current protectionAdjustable current control lets you set the maximum current output with a potentiometer which lets you use voltages above your stepper motors rated voltage to achieve higher step ratesMore info please click here3 UNO R3 Development BoardInstructions ① Download theIDE http cc en Main Software②Download the USB chip driver http www wch ic com download list asp Id 126③Plug in the UNO development board the driver will automatically install④In the die inside select the board UNO⑤Select the COM port this can find in my computer make the uno development board inside the port⑥Best to chooseown routine program burn