A4988 Stepper Motor Driver Module with Heatsink

A4988 Stepper Motor Driver Module with Heatsink

Features
- Simple step and direction control interface
- Five different step resolutions
- Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates
- Intelligent 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 protection

Specifications
- Minimum operating voltage: 8 V
- Maximum operating voltage: 35 V
- Continuous current per phase: 1 A (without a heat sink or forced air flow.)
- Maximum current per phase: 2 A (with additional cooling)
- Minimum logic voltage: 3 V
- Maximum logic voltage: 5.5 V
- Microstep resolutions:  full, 1/2, 1/4, 1/8, and 1/16
- Microstep resolution: 200-3200 pulse/turn
- Operating Temperature: 20~85°C

Dimensions
Dimension: 15 x 20 mm / 0.6 × 0.8 inches

these pins we can set the motors to one of the five step resolutions.
MS1     MS2      MS3     Microstep Resolution
Low      Low      Low     Full step
High     Low      Low     1/2 step
Low      High     Low     1/4 step
High     High     Low     1/8 step
High     High     High    1/16 step

These three microstep selection pins are pulled LOW by internal pull-down resistors, so if we leave them disconnected, the motor will operate in full step mode.