diff --git a/Inc/main.h b/Inc/main.h
index db6aa74..f02b79b 100644
--- a/Inc/main.h
+++ b/Inc/main.h
@@ -41,7 +41,7 @@ extern "C" {
 
 /* Exported constants --------------------------------------------------------*/
 /* USER CODE BEGIN EC */
-#define BUFFER_SIZE 8
+#define BUFFER_SIZE 515
 extern uint8_t rxBuffer[BUFFER_SIZE];
 /* USER CODE END EC */
 
diff --git a/Src/main.c b/Src/main.c
index 806c68a..4100cb1 100644
--- a/Src/main.c
+++ b/Src/main.c
@@ -58,11 +58,11 @@ static void MX_GPIO_Init(void);
 
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
-#define BUFFER_SIZE 8
+#define BUFFER_SIZE 515
 uint8_t rxBuffer[BUFFER_SIZE];
+uint16_t rxBufferPos = 0;
 
 void init_UART1(){
-    USART1->CR1 &= ~USART_CR1_UE;
     RCC->APBENR2 |= RCC_APBENR2_USART1EN;
     RCC->IOPENR |= RCC_IOPENR_GPIOCEN;
 
@@ -72,8 +72,11 @@ void init_UART1(){
     GPIOC->AFR[0] |= 1 << GPIO_AFRL_AFSEL5_Pos;
 
     USART1->BRR = 128; // 32000000÷250000
-    USART1->CR3 |= USART_CR3_EIE;
     USART1->CR1 = USART_CR1_RE;
+
+    USART1->CR3 |= USART_CR3_EIE;
+    USART1->CR1 |= USART_CR1_RXNEIE_RXFNEIE;
+
     USART1->CR1 |= USART_CR1_UE;
 
     HAL_NVIC_SetPriority(USART1_IRQn, 0, 0);
@@ -81,6 +84,38 @@ void init_UART1(){
 }
 /* USER CODE END 0 */
 
+void USART1_IRQHandler(){
+     if(USART1->ISR & USART_ISR_RXNE_RXFNE){
+         //printf("%x ", USART1->RDR);
+         rxBuffer[rxBufferPos++] = USART1->RDR;
+         if(rxBufferPos >= BUFFER_SIZE){
+             rxBufferPos = 0;
+         }
+     }
+
+     if(USART1->ISR & USART_ISR_FE){
+         USART1->ICR = USART_ICR_FECF;
+         printf("FE after %d\n",rxBufferPos);
+         rxBufferPos = 0;
+         printf("buf: ");
+         for(uint16_t i=0; i<10; i++)
+             printf("0x%02X ", rxBuffer[i]);
+         printf("\n");
+     }
+     if(USART1->ISR & USART_ISR_ORE){
+         USART1->ICR = USART_ICR_ORECF;
+         printf("ORE\n");
+     }
+     if(USART1->ISR & USART_ISR_NE){
+         USART1->ICR = USART_ICR_NECF;
+         printf("NE\n");
+     }
+     if(USART1->ISR & USART_ISR_UDR){
+         USART1->ICR = USART_ICR_UDRCF;
+         printf("UDR\n");
+     }
+}
+
 /**
   * @brief  The application entry point.
   * @retval int
@@ -112,20 +147,6 @@ int main(void)
   MX_GPIO_Init();
   /* USER CODE BEGIN 2 */
   init_UART1(); 
-
-  printf("CR1   init: 0x%02lX\n", USART1->CR1  );
-  printf("CR2   init: 0x%02lX\n", USART1->CR2  );
-  printf("CR3   init: 0x%02lX\n", USART1->CR3  );
-  printf("BRR   init: 0x%02lX\n", USART1->BRR  );
-  printf("GTPR  init: 0x%02lX\n", USART1->GTPR );
-  printf("RTOR  init: 0x%02lX\n", USART1->RTOR );
-  printf("RQR   init: 0x%02lX\n", USART1->RQR  );
-  printf("ISR   init: 0x%02lX\n", USART1->ISR  );
-  printf("ICR   init: 0x%02lX\n", USART1->ICR  );
-  printf("RDR   init: 0x%02lX\n", USART1->RDR  );
-  printf("TDR   init: 0x%02lX\n", USART1->TDR  );
-  printf("PRESC init: 0x%02lX\n", USART1->PRESC);
-
   /* USER CODE END 2 */
 
   /* Infinite loop */
@@ -133,8 +154,6 @@ int main(void)
   //HAL_UART_Receive_DMA(&huart1, rxBuffer, BUFFER_SIZE);
   while (1)
   {
-     if(USART1->ISR & USART_ISR_RXNE_RXFNE)
-         printf("char: '%c'\n", USART1->RDR);
     /* USER CODE END WHILE */
 
     /* USER CODE BEGIN 3 */