A4988 Stepper Motor Controller
This feature is not included in precompiled binaries
When compiling your build add the following to
#ifndef USE_A4988_STEPPER #define USE_A4988_STEPPER // A4988/DRV8825 stepper motor (+10k5 code) #endif
This driver is used to control stepper-motors such as NEMA 17.
The driverboard has several connectors: powering the controller (3.3-5.0 V), input (+/-) & output (1a/1b/2a/2b), the motor (up to 35V/2A), and to control the circuit (in order at the control side of the board):
|DIR||Direction of rotation|
|MS1||Microstep increment select|
|MS2||Microstep increment select|
|MS3||Microstep increment select|
|EN||Enable the power supply for the motor|
|SLP||Sleep (bridge to RST)|
|RST||Reset (bridge to SLP)|
There are six GPIO components that should be configured to free GPIOs:
A4988 DIR (170) A4988 STP (171) A4988 ENA (172) A4988 MS1 (173) A4988 MS2 (174) A4988 MS3 (175)
STEPsignals. In such a configuration the motor will be permanently powered and microstepping will be set to 1/1 (full steps).
Detailed information about the A4988 controller can be found in the datasheet.
The DRV8825 is directly pin compatible with the A4988. The microstepping increment settings are different. Also, there is one additional option on the DRV8825.
Refer to the Stepper Motor Commands
MotorRPM is an imprecise setting due to the implementation method. Also, if the value is too high for the combination of chosen micro stepping increment (
MotorMIS) and the number of steps the given motor needs for one revolution (
MotorSPR), the motor will not turn but make a whining noise. You will have to experiment some to find the optimal combination for your use case.
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