MIKROE Stepper 17 Click is a compact add-on board that contains a bipolar stepper motor driver. This board features the TB67S539FTG, a two-phase bipolar stepping motor driver using a PWM chopper from Toshiba Semiconductor. It supports a PWM constant-current control drive without a current sense resistor for motor-current detection and full-step to 1/32 steps resolution for less motor noise and smoother control. It has a wide operating voltage range of 4.5V to 34V with an output current capacity of 1.8A maximum in addition to several anomaly detection indicators. This Click board™ makes the perfect solution for small stepping motors in a wide range of applications such as office automation, commercial and industrial equipment.

Stepper 17 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Stepper 17 Click as its foundation uses the TB67S539FTG, a two-phase bipolar stepping motor driver with resistorless current sensing from Toshiba Semiconductor. The TB67S539FTG incorporates low on-resistance DMOS FETs, which can deliver a 1.8A maximum current with a motor output voltage rating of 40V, in addition to integrated protection mechanisms such as over-current and over-temperature detection (ISD and TSD LED indicators). It supports full-step to 1/32 steps resolution for less motor noise and smoother control, with a built-in mixed decay mode which helps to stabilize the current waveforms.

Thanks to the many steps that TB67S539FTG supports, motor noise can be significantly reduced with smoother operation and more precise control. It is suited to a wide range of applications such as office automation, commercial, and industrial equipment using stepping motors supporting an operational temperature range covering -20°C to +85°C. The current value is set by the reference voltage value obtained by the MCP1501, a high-precision voltage regulator. The current threshold point of the TB67S539FTG, alongside MCP1501, can be set manually using an onboard trimmer labeled as VR.

In addition to the I2C communication, several GPIO pins connected to the mikroBUS™ socket pins are also used to forward the information to the MCU, associated with the PCA9555A port expander. The PCA9555A also allows choosing the least significant bit (LSB) of its I2C peripheral address by positioning SMD jumpers labeled as ADDR SEL to an appropriate position marked as 0 and 1, alongside its interrupt feature routed to the INT pin of the mikroBUS™ socket.

The CLK clock signal, routed to the PWM pin of the mikroBUS™ socket, shifts the current step and electrical angle of the motor with its every up-edge, while the Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption used for power ON/OFF purposes. All circuits, including the interface pins, are inactive in this state, and the TB67S539FTG is in the form of minimum power consumption. A simple DIR pin routed to the AN pin on the mikroBUS™ socket allows MCU to manage the direction of the stepper motor (clockwise or counterclockwise), while the RST pin of the mikroBUS™ socket initializes an electrical angle in the internal counter to set an initial position.

A specific addition to this Click board™ is a multifunctional switch that allows the user, by selecting a particular switch, to set appropriate features such as:

• 1 – Sleep Mode Activation
• 2 , 3 – Motor Torque Setting
• 4 , 5 – Mixed Decay Control
• 6 , 7 , 8 – Step Resolution Setting

The Stepper 17 Click supports an external power supply for the TB67S539FTG, which can be connected to the input terminal labeled as VM and should be within the range of 4.5V to 34V, while the stepper motor coils can be connected to the terminals labeled as B+, B-, A-, and A+.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

• Interface: GPIO, I²C
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V, External
• Supply Voltage VCC: Min. 3.3V, Max. 5V
• External Supply Voltage VM: Min. 4.5V, Max. 34V
• Maximum Output Current: 1.8A
• Maximum Step Clock Frequency: 250kHz
• Operating Temperature Range: min. -20°C, Typ. +25°C, Max. +85°C

• Schematic
• MCP1501 Datasheet
• PCA9555A Datasheet
• TB67S539FTG Datasheet
• mikroSDK
• GitHub