Stepper 3 Click

How does it work?

Stepper 3 Click is based on the ULN2003A, a high-voltage, high-current Darlington transistor array from Texas Instruments. Motor step progression is performed by alternating the active driver, which sinks the current through the coil connected to the respective driver. The MCU performs the alteration cycle, which controls the driver inputs: a HIGH logic level on the input pin will set the corresponding driver to a LOW logic level, allowing it to sink current. Besides driving a unipolar stepper motor as the primary function, this Click board™ can also be used for driving relays and brushed DC motors or as the logic buffer for various applications. Combining more than one driver makes it possible to sink more than 500mA.

Stepper 3 Click uses four GPIOs to allow the host MCU to control the stepper motor or other mentioned device. Those pins are labeled as INA, INB, INC, and IND. Four output channels from the ULN2203A and a motor power supply are routed to the unpopulated 5-pin header. The motor can be powered over the 5V rail of the mikroBUSTM socket or the external power supply terminal with voltages of 5 – 30V. The selection can be made over the MOTOR PWR jumper. In addition, the ULN2003As output channels are also routed to the four output LEDs (outA, outB, outC, and outD) for a visual presentation.

This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on Stepper 3 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Channel A ctrl IN	INA	1	AN	PWM	16	IND	Channel D ctrl IN
Channel B ctrl IN	INB	2	RST	INT	15	NC
Channel C ctrl IN	INC	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
	NC	7	3.3V	5V	10	5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Stepper 3 click electrical specifications

Software Support

We provide a library for the Stepper 3 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Stepper 3 Click driver.

Key functions

• stepper3_set_step_mode This function sets the step mode resolution settings in ctx->step_mode.

• stepper3_set_direction This function sets the motor direction to clockwise or counter-clockwise in ctx->direction.

• stepper3_drive_motor This function drives the motor for the specific number of steps at the selected speed.

Example Description

This example demonstrates the use of the Stepper 3 click board by driving the motor in both directions for a desired number of steps.

void application_task ( void ) 
 { 
     log_printf ( &logger, " Move 64 full steps clockwise rnn" ); 
     stepper3_set_step_mode ( &stepper3, STEPPER3_MODE_FULL_STEP ); 
     stepper3_set_direction ( &stepper3, STEPPER3_DIR_CW ); 
     stepper3_drive_motor ( &stepper3, 64, STEPPER3_SPEED_FAST ); 
     Delay_ms ( 1000 );
     Delay_ms ( 1000 ); 

     log_printf ( &logger, " Move 128 half steps counter-clockwise rnn" ); 
     stepper3_set_step_mode ( &stepper3, STEPPER3_MODE_HALF_STEP ); 
     stepper3_set_direction ( &stepper3, STEPPER3_DIR_CCW ); 
     stepper3_drive_motor ( &stepper3, 128, STEPPER3_SPEED_VERY_FAST ); 
     Delay_ms ( 1000 );
     Delay_ms ( 1000 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Stepper3

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.