step motor turns, minimal example

Src/main.c

@@ -145,6 +145,7 @@ void USART1_IRQHandler(){
      }
 
      if(USART1->ISR & USART_ISR_FE){
+         //TODO read rx==0
          USART1->ICR = USART_ICR_FECF;
          //if(rxBufferPos != 514)
          //    printf("FE after %d\n",rxBufferPos);
@@ -182,6 +183,27 @@ void DMA1_Channel1_IRQHandler(){
     SEGGER_SYSVIEW_PrintfHost("DMA");
     SEGGER_SYSVIEW_RecordExitISR();
 }
+
+void init_stepper(){
+    RCC->IOPENR |= RCC_IOPENR_GPIOBEN;
+    RCC->IOPENR |= RCC_IOPENR_GPIOCEN;
+    RCC->IOPENR |= RCC_IOPENR_GPIOEEN;
+
+    // Set to output (00: Input, 01: Output, 10: Alternate function, 11: Analog)
+    // PB4 Direction
+    GPIOB->MODER &= ~(0x3 << (4 * 2)); // Clear mode bits for PB4
+    GPIOB->MODER |= (0x1 << (4 * 2));  // Set mode to output for PB4
+
+    // PC11 Enable
+    GPIOC->MODER &= ~(0x3 << (11 * 2)); // Clear mode bits for PC11
+    GPIOC->MODER |= (0x1 << (11 * 2));  // Set mode to output for PC11
+
+    // PE2 Step
+    GPIOE->MODER &= ~(0x3 << (2 * 2));   // Clear mode bits for PE2
+    GPIOE->MODER |= (0x1 << (2 * 2));    // Set mode to output for PE2
+
+    GPIOC->BSRR |= GPIO_BSRR_BS11;
+}
 /* USER CODE END 0 */
 
 /**
@@ -190,9 +212,8 @@ void DMA1_Channel1_IRQHandler(){
   */
 int main(void)
 {
-
   /* USER CODE BEGIN 1 */
-    /* USER CODE END 1 */
+  /* USER CODE END 1 */
 
   /* MCU Configuration--------------------------------------------------------*/
 
@@ -218,11 +239,13 @@ int main(void)
   MX_GPIO_Init();
   /* USER CODE BEGIN 2 */
   init_UART1_dma(); 
+  init_stepper();
   /* USER CODE END 2 */
 
   /* Infinite loop */
   /* USER CODE BEGIN WHILE */
   //HAL_UART_Receive_DMA(&huart1, rxBuffer, BUFFER_SIZE);
+  uint16_t cnt = 0;
   while (1)
   {
       printf("buf: ");
@@ -230,6 +253,10 @@ int main(void)
           printf("0x%02X ", rxBuffer[i]);
       printf("\n");
       SEGGER_SYSVIEW_OnIdle();
+      if(cnt++ >= 260-rxBuffer[1]){
+          cnt = 0;
+          GPIOE->ODR ^= GPIO_ODR_OD2;
+      }
     /* USER CODE END WHILE */
 
     /* USER CODE BEGIN 3 */