Pololu modular stepper motor controllers

Date of publication: 31-01-2023 🕒 4 min read

DRV8434S by TI is a stepper motor controller with a resolution of up to 1/256-step. The operating current per motor phase is 1.2 A, and the maximum peak instantaneous current can reach up to 2 A – the device achieves these parameters without forced air circulation, no heat sink is required either. The driver has an integrated axis stall detection circuit and uses a ripple control algorithm to provide fine adjustment of current and increase motor performance.

The above-mentioned controller is implemented in POLOLU-376x modules supplied by Pololu. The models are available in three versions: the 3764 basic one, controlled via STEP (step) and DIR (direction) pins, the 3766 extended version featuring an SPI interface and the 3768 version (without a potentiometer for current limit control). The 3765, 3767 and 3769 versions are their respective, almost identical counterparts. The only difference is that they come with soldered pin headers (the so-called goldpin), and therefore they require no soldering at all when mounted on a breadboard. Furthermore, in the case of models equipped with an SPI interface, you can scale the maximum current using software.

Stepper motor controller: POLOLU-3767

The module is equipped with overtemperature, short-circuit and overcurrent protection. Thanks to the use of the chip supplied by TI, the product boasts wide functionality, as it can operate with a resolution ranging from 1/256-step to 1/1-step. With the integrated voltage converter (with capacitors placed on the PCB), the circuit minimises the electromagnetic interference (EMI).

It is also noteworthy that the power supplied to the motor can range from 4.5V to 48V DC, while the controller requires voltage in the range of 1.8V to 5.5V DC – which makes it compatible with all commonly applied microcontrollers. There are free libraries available on the GitHub platform to control the DRV8434S via Arduino. Thanks to the support for lower voltages, Pololu modules can also be easily used with Raspberry Pi computers (using the high-level Python language).

POLOLU-376x modules

Parameters
Module type:	stepper motor controller
Integrated circuit *:	DRV8434A or DRV8434S
Continuous output current per channel:	1.2 A
Motor input voltage:	4.5...48 V
Logic input voltage:	1.8...5.5 V
PCB dimensions*:	15.2x20.3 mm or 15.3x20.3 mm
Colour:	green
Resolution:	1/256…1/1-step