message: Fix step_cb per
diff: @@ -118,8 +118,8 @@ bool Axis::wait_for_current_meas() {
  // step/direction interface
  void Axis::step_cb() {
  - const GPIO_PinState dir_pin = (GPIO_PinState)(dir_port_->IDR & dir_pin_);
  - const int32_t dir = (1 - 2 * (int32_t)dir_pin) * step_dir_active_;
  + const bool dir_pin = dir_port_->IDR & dir_pin_;
  + const int32_t dir = (-1 + 2 * dir_pin) * step_dir_active_;
  controller_.input_pos_ += dir * config_.counts_per_step;
  controller_.input_pos_updated();
  };
  