Product description: EasyDriver A3967 - 30V 0.7A stepper motor controller - SparkFun ROB-12779.
The system allows to control the stepper motor with a device allowing to generate logical states e.g. Arduino, STM32Discovery , Raspberry Pi. The module is very simple to use and is compatible with 4, 6 and 8-wire stepper motors.
|The system can be configured to work with 3.3V. For this purpose, a jumper marked 3/5V must be soldered.|
Connection of the controller
The motor's dischargevoltage should be connected to the outputs marked PWR IN - positive pole M+, GND ground. The stepper motor outputs are connected to the MOTOR pins - coil A and B. Control is carried out through the DIR(direction) and STEP (step ) pins. If the striking signals are supplied from a source other than themotor voltage, the control system ground should also be connected to the GND pin.
In order to turn the motor one step at a time, the STEP output should have a high state (logical one), the next sequence of zeroes and ones will move the motor by another step, etc. The direction is selected by entering the appropriate state on the DIR output (e.g. low state - clockwise rotation, high state - opposite). The controller also has the ability to select theresolution of the motor.
Detailed description together with sample code for Arduino can be found at this address.
Connecting and disconnecting the motor while the controller is on can damage the system.
Resolution of the stepper motor controller
The step size is selected using the inputsMS1, MS2. The possible settings are shown in the table below. Inputs MS1, MS2 and MS3 have a built-in pull-up resistor (10 kOm), so by default the chip operates in 1/8th step mode.
The Easy Driver module allows for active current limitation by means of a potentiometer. One of the ways to introduce the limitation is to set the controller to full step mode and to measure the current flowing through one coil without giving a signal to the STEP input.
EasyDriver stepper motor controller specification A3967
- Motor supply voltage: 7 V - 30 V
- Current: max 0.7 A per coil
- Simple control interface
- 5 different modes of operation: full step, 1/2, 1/4, 1/8
- Possibility to adjust the current drawn by the motor by means of a potentiometer
- The module is compatible with 4, 6 and 8-wire stepper motors
- Control is by 5 V or 3.3 V signals (after soldering the jumper)
- Module dimensions: 48 x 11 mm