diff --git a/Makefile b/Makefile
index 9281e3a..2fc3cdd 100644
--- a/Makefile
+++ b/Makefile
@@ -93,7 +93,8 @@ C_INCLUDES =  \
 -IDrivers/STM32F1xx_HAL_Driver/Inc \
 -IDrivers/STM32F1xx_HAL_Driver/Inc/Legacy \
 -IDrivers/CMSIS/Device/ST/STM32F1xx/Include \
--IDrivers/CMSIS/Include
+-IDrivers/CMSIS/Include \
+-Ilib/crc/src
 
 
 # compile gcc flags
diff --git a/lib/crc/src/crc32.h b/lib/crc/src/crc32.h
new file mode 100644
index 0000000..8d669a0
--- /dev/null
+++ b/lib/crc/src/crc32.h
@@ -0,0 +1,40 @@
+/* Simple public domain implementation of the standard CRC32 checksum.
+ * Outputs the checksum for each file given as a command line argument.
+ * Invalid file names and files that cause errors are silently skipped.
+ * The program reads from stdin if it is called with no arguments. */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+uint32_t crc32_for_byte(uint32_t r) {
+  for(int j = 0; j < 8; ++j)
+    r = (r & 1? 0: (uint32_t)0xEDB88320L) ^ r >> 1;
+  return r ^ (uint32_t)0xFF000000L;
+}
+
+void crc32(const void *data, size_t n_bytes, uint32_t* crc) {
+  static uint32_t table[0x100];
+  if(!*table)
+    for(size_t i = 0; i < 0x100; ++i)
+      table[i] = crc32_for_byte(i);
+  for(size_t i = 0; i < n_bytes; ++i)
+    *crc = table[(uint8_t)*crc ^ ((uint8_t*)data)[i]] ^ *crc >> 8;
+}
+/*
+int main(int ac, char** av) {
+  FILE *fp;
+  char buf[1L << 15];
+  for(int i = ac > 1; i < ac; ++i)
+    if((fp = i? fopen(av[i], "rb"): stdin)) {
+      uint32_t crc = 0;
+      while(!feof(fp) && !ferror(fp))
+        crc32(buf, fread(buf, 1, sizeof(buf), fp), &crc);
+      if(!ferror(fp))
+        printf("%08x%s%s\n", crc, ac > 2? "\t": "", ac > 2? av[i]: "");
+      if(i)
+        fclose(fp);
+    }
+  return 0;
+}
+*/
diff --git a/src/main.c b/src/main.c
index b737a77..90a6ac1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -24,6 +24,8 @@
 #include "setup.h"
 #include "config.h"
 //#include "hd44780.h"
+#include "crc32.h"
+#include <stdbool.h>
 
 void SystemClock_Config(void);
 
@@ -43,7 +45,7 @@ int cmd3;
 typedef struct{
    int16_t steer;
    int16_t speed;
-   //uint32_t crc;
+   uint32_t crc;
 } Serialcommand;
 
 volatile Serialcommand command;
@@ -89,6 +91,19 @@ void poweroff() {
     }
 }
 
+bool checkCRC(Serialcommand* command) {
+	uint32_t crc = 0;
+	crc32((const void *)command, 4, &crc); // 4 2x uint16_t = 4 bytes
+
+	setScopeChannel(0, (int)crc);  // 1: ADC1
+	setScopeChannel(1, (int)command->crc);  // 2: ADC2
+
+
+	if(command->crc == crc) {
+		return true;
+	}
+	return false;
+}
 
 int main(void) {
   HAL_Init();
@@ -150,7 +165,7 @@ int main(void) {
 
   #ifdef CONTROL_SERIAL_USART2
     UART_Control_Init();
-    HAL_UART_Receive_DMA(&huart2, (uint8_t *)&command, 4);
+    HAL_UART_Receive_DMA(&huart2, (uint8_t *)&command, 8);
   #endif
 
   #ifdef DEBUG_I2C_LCD
@@ -212,8 +227,16 @@ int main(void) {
     #endif
 
     #ifdef CONTROL_SERIAL_USART2
+      if(checkCRC(&command))
+      {
       cmd1 = CLAMP((int16_t)command.steer, -1000, 1000);
       cmd2 = CLAMP((int16_t)command.speed, -1000, 1000);
+      } else
+      {
+    	  cmd1 = 0;
+    	  cmd2 = 0;
+      }
+
 
       timeout = 0;
     #endif