USTEPPER S32

uStepper S32 is the newest generation of uStepper ultra-compact Arduino compatible boards, with integrated stepper driver and 15-bit rotary encoder, enabling the uStepper S32 to be mounted directly on the back of your NEMA 17 size stepper motor. This makes it possible to develop applications using a stepper motor, without the need for long and messy wiring to an external Arduino/stepper shield. Furthermore the 15-bit rotary encoder ensures that the absolute position of the motor shaft can be tracked, enabling the uStepper S32 to detect any loss of steps !

A video tutorial walking you through the initial setup steps can be found here !

Application examples can be found here !

Hardware specs

The uStepper S32 has the following hardware highlights:

• Compact design, fitting on the back of a NEMA 17 size stepper motor (41.8 mm x 41.8 mm)
• Capable of driving both NEMA 17 and NEMA 23 stepper motors
• Incorporates the Trinamic TMC5130 with integrated ramp controller and dynamic microstepping for minimal load on the MCU and very smooth operation
• Driver delivers 2.5 A current (peak)
• New STM32F401 32-bit 84MHz Cortex®-M4 MCU
• USB-C interface
• 15-bit encoder (0.011 degrees resolution)
• Current is set in software by a simple command 
• Supply voltage 8 - 42 V
• Reverse polarity protection

All together making the uStepper S32 a powerful standalone Arduino compatible stepper controller !

Stepper driver chip

The uStepper S32 board contains a serious powerhouse of a stepper driver chip, the TMC5130 from Trinamic !

Furthermore, it features an native 1/256th microstepping processing engine, complete with acceleration and deceleration ramping profiles, to give smooth transition to the desired speed. The native 1/256th microstepping not only ensures low noise levels and smooth operation, it also improves the precision of your application, by reducing the smallest step size of the motor to an astonishing 0.007 degrees (assuming a motor with 200 steps per revolution)! To put this into perspective, if the motor was mounted onto a CNC machine, where the axis moves 10 mm per full rotation, this would correspond to a resolution of 0.195 microns !

Encoder

As the resolution of the stepper driver increases, the requirement for reliable position sensing resolution increases as well. For uStepper S32 we have chosen a reliable 15-bit encoder from Infineon, delivering 0.011 degrees resolution ! The encoder is used for the feedback loop, to correct if any steps are lost and thus reliable and accurate readings is essential. 

In this case, the controller reads the encoder value to determine whether a step needs to be issued (in either direction) or not. Here the driver has a resolution of 0.007 degrees, meaning that a sensor reading with a greater deviation than 0.007 degrees from the expected position results in a microstep needing to be generated, in order to compensate.

Switch mode voltage regulator

In order to allow for higher motor voltages a switch mode voltage regulator to create the 5V for the logic circuits on the PCB is embedded. This ensures that the uStepper S32 can handle input voltages of up to 42V !

This high supply voltage has the benefits of increasing the stepper drivers ability to overcome the back EMF voltage generated by the motor, and hereby increasing the available torque at increasing velocities, compared to lower supply voltages.

Requirements for stepper motor:

uStepper S32 fits standard NEMA 17 size stepper motors, that is stepper motors with a distance of 31 mm between center of holes (along the sides). The mount extends 2 mm down the side of the stepper motor, requiring you stepper to not have any obstacles like a connector conflicting with the mount. The magnet for the encoder is 8 mm in diameter, requiring a hole of at least this size. We have tested a couple of brands/models and not found problems with fitting uStepper S32. We can not be held responsible for stepper motor fitting problems - if in any doubt whether uStepper S32 will fit your motor, contact us or buy the motor from us!