driving power stages for two bi-polar stepper motors with single STM32F4?

[markus2399]

Posted on November 07, 2013 at 10:30

Hi!

The STM32F4 would be ideally suited to drive the power stages (H-bridges) for two bi-polar stepper motors in micro-stepping mode without external circuitry if it had four complementary outputs for timers 1 and 8 each. However, timer channel 4 lacks the complementary output according to the reference manual (figures 99 and 100), and there are no TIM1_CH4N and TIM8_CH4N pins. Of course this could be simulated by explicitly programming individual port pins, but we are looking for a simple and precise solution, preferably based on the PWM generators with dead-time generation and DMA-controlled update of the duty cycle. I can hardly believe that ST missed the opportunity to enter this market by just arbitrarily omitting such a feature, so my question is if there is a different (simple) way to achieve the same (driving 8 complementary MOSFET stages, i.e., 4 H-bridges). I found several articles in this forum discussing the complementary outputs, but none answering the above question. Does anybody have an idea? Thanks & kind regards, Markus #complementary-outputs

[frankmeyer9]

Posted on November 07, 2013 at 10:58

I can hardly believe that ST missed the opportunity to enter this market by just arbitrarily omitting such a feature, ...

The STM32F4 is more a general purpose MCU, with versions to satisfy the ''average'' market requirements. ST (and other vendors, too) offer application-specific MCUs with exactly the features you asked for. These MCUs are rather tailored to the needs of specific customers. You may ask you nearest ST distributor/FAE about the STLux family (STM8 based). My last company used this chips. And about a year ago, ST was talking about plans to develop a STM32-based version. Alternatively, I remember promising offers from Renesas and Microchip ...