Feature:1. Development Board:2. The design of circuit diagram is open, and the development software interface is free to download, or you can modify it according to your needs. Sensors and various electronic component can be connected easily. Using a high-speed microprocessor controller, the development interface and environment are very simple and easy to understand, very suitable for beginners to learn.3. V4 Plotter Expansion Board:4. This expansion board can be used as a driver expansion board for engraving machines, 3D printers, etc. It has 3 channels of slots in the 3-channel A4988 stepper motor driver module for driving stepper motors (not included). Each channel of the stepper motor only needs 2iO ports, which means 6iO ports are enough to manage 3 stepper motors.​5. A4988 Motor Driver Module:6. The A4988 is a complete -stepper motor driver with a built-in converter for easy operation. It can operate bipolar stepper motors in full, half, 1/4, 1/8 and 1/16 stepper modes with output drive performance up to 35 V and +1A. The A4988 includes a fixed-off time current regulator that can operate in slow or mixed decay modes. The converter is the button to the ease of implementation of the A4988. As long as the \"step\" input in a pulse, you can drive the motor to generate -steps. The A4988 interface is perfect for complex microprocessor unavailability or overload applications.7. During microstep operation, the choppers control within the A4988 automatically selects the current decay mode (slow or mixed). In the mixed decay mode, the device is initially set to decay quickly for a fixed part of the downtime and then decay slowly for the remainder of the downtime. The mixed decay current control scheme reduces audible motor noise, increases stepping accuracy, and reduces power consumption. Internal synchronous rectification control circuitry is provided to improve power consumption during pulse width modulation (PWM) operation. Internal circuit protections includes: thermal shutdown with hysteresis, undervoltage lockout (UVLO). The A4988 is available in a surface mount QFN package with a nominal overall package height of 0.90mm and an exposed heat sink for enhanced heat dissipation.8. A4988 Features:9. Low RDS (on) output. Automatic current decay mode detection/selection. Mixed and slow current decay modes. Synchronous rectification for low power dissipation. Internal UVLO. 3.3 and 5V compatible logic power supplies. Thermal shutdown circuitry. Ground short circuit protections. Loaded short circuit protections. Five selectable stepping modes: full, 1/2, 1/4, 1/8 and 1/16.10. DRV8825 Features:11. Suitable for driving stepper motors up to 8.2V~45V 2.5A. Only simple stepping and direction control interface. Six different stepping modes: full, half, 1/4, 1/8, 1/16, 1/32. Adjustable potentiometer to adjust current output for higher step rates. Automatic current decay mode detection/selection. Overheat shutdown circuit, undervoltage lockout. Ground short circuit protections and load short circuit protections.12. Compared to 4988, the advantages of DRV8825 are:13. Current up to: 2.5A Support up to: 1/32 stepping mode 4-layer printed circuit board, better heat dissipation performance. Chip internal resistance is smaller, low heat generation, fine heat dissipation.Specification:This set includes 1pcs development board, 1pcs V4 board, 4pcs stepper, 1pcs 40-pin row of pins, and 1pcs cable. Two specifications available, you can choose A4988 set or 8825 set according to your demands. Compared to 4988, the advantages of DRV8825 are: support 2.5A current, support 1/32 stepping mode, 4-layer printed circuit board design, with better heat dissipation performance. Chip internal resistance is smaller, low heat generation, nice heat dissipation.Features:Development Board:The design of circuit diagram is open, and the development software interface is free to download, or you can modify it according to your needs. Sensors and various electronic component can be connected easily. Using a high-speed microprocessor controller , the development interface and environment are very simple and easy to understand, very suitable for beginners to learn.V4 Plotter Expansion Board:This expansion board can be used as a driver expansion board for engraving machines, 3D printers, etc. It has 3 channels of slots in the 3-channel A4988 stepper motor driver module for driving stepper motors (not included). Each channel of the stepper motor only needs 2iO ports, which means 6iO ports are enough to manage 3 stepper motors.​A4988 Motor Driver Module:The A4988 is a complete microstepper motor driver with a built-in converter for easy operation. It can operate bipolar stepper motors in full, half, 1/4, 1/8 and 1/16 stepper modes with output drive performance up to 35 V and +1A. The A4988 includes a fixed-off time current regulator that can operate in slow or mixed decay modes. The converter is the button to the ease of implementation of the A4988. As