diff --git a/MotorControl/low_level.c b/MotorControl/low_level.c
index 90ff6f5b..e37da115 100644
--- a/MotorControl/low_level.c
+++ b/MotorControl/low_level.c
@@ -197,7 +197,7 @@ void motor_parse_cmd(uint8_t* buffer, int len) {
         // position control
         uint8_t motor_number;
         float pos_setpoint, vel_feed_forward, current_feed_forward;
-        int numscan = sscanf(buffer, "p %u %f %f %f", &motor_number, &pos_setpoint, &vel_feed_forward, &current_feed_forward);
+        int numscan = sscanf((const char*)buffer, "p %hhu %f %f %f", &motor_number, &pos_setpoint, &vel_feed_forward, &current_feed_forward);
         if (numscan == 4 && motor_number < num_motors) {
             set_pos_setpoint(&motors[motor_number], pos_setpoint, vel_feed_forward, current_feed_forward);
         }
@@ -205,7 +205,7 @@ void motor_parse_cmd(uint8_t* buffer, int len) {
         // velocity control
         uint8_t motor_number;
         float vel_feed_forward, current_feed_forward;
-        int numscan = sscanf(buffer, "v %u %f %f", &motor_number, &vel_feed_forward, &current_feed_forward);
+        int numscan = sscanf((const char*)buffer, "v %hhu %f %f", &motor_number, &vel_feed_forward, &current_feed_forward);
         if (numscan == 3 && motor_number < num_motors) {
             set_vel_setpoint(&motors[motor_number], vel_feed_forward, current_feed_forward);
         }
@@ -213,7 +213,7 @@ void motor_parse_cmd(uint8_t* buffer, int len) {
         // current control
         uint8_t motor_number;
         float current_feed_forward;
-        int numscan = sscanf(buffer, "c %u %f ", &motor_number, &current_feed_forward);
+        int numscan = sscanf((const char*)buffer, "c %hhu %f ", &motor_number, &current_feed_forward);
         if (numscan == 2 && motor_number < num_motors) {
             set_current_setpoint(&motors[motor_number], current_feed_forward);
         }
diff --git a/Src/syscalls.c b/Src/syscalls.c
index 9a6f0517..7a2e590a 100644
--- a/Src/syscalls.c
+++ b/Src/syscalls.c
@@ -17,7 +17,7 @@
 int _write(int file, char *data, int len) {
 
   // transmit over CDC
-  uint8_t status = CDC_Transmit_FS(data, len);
+  uint8_t status = CDC_Transmit_FS((uint8_t*)data, len);
 
   // return number of bytes written
   return (status == USBD_OK ? len : 0);
diff --git a/Src/usbd_desc.c b/Src/usbd_desc.c
index 4637f09f..d5741388 100644
--- a/Src/usbd_desc.c
+++ b/Src/usbd_desc.c
@@ -248,11 +248,11 @@ uint8_t *  USBD_FS_ProductStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *len
 {
   if(speed == 0)
   {
-    USBD_GetString (USBD_PRODUCT_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_PRODUCT_STRING_FS, USBD_StrDesc, length);
   }
   else
   {
-    USBD_GetString (USBD_PRODUCT_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_PRODUCT_STRING_FS, USBD_StrDesc, length);
   }
   return USBD_StrDesc;
 }
@@ -266,7 +266,7 @@ uint8_t *  USBD_FS_ProductStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *len
 */
 uint8_t *  USBD_FS_ManufacturerStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *length)
 {
-  USBD_GetString (USBD_MANUFACTURER_STRING, USBD_StrDesc, length);
+  USBD_GetString ((uint8_t *)USBD_MANUFACTURER_STRING, USBD_StrDesc, length);
   return USBD_StrDesc;
 }
 
@@ -281,11 +281,11 @@ uint8_t *  USBD_FS_SerialStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *leng
 {
   if(speed  == USBD_SPEED_HIGH)
   {
-    USBD_GetString (USBD_SERIALNUMBER_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_SERIALNUMBER_STRING_FS, USBD_StrDesc, length);
   }
   else
   {
-    USBD_GetString (USBD_SERIALNUMBER_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_SERIALNUMBER_STRING_FS, USBD_StrDesc, length);
   }
   return USBD_StrDesc;
 }
@@ -301,11 +301,11 @@ uint8_t *  USBD_FS_ConfigStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *leng
 {
   if(speed  == USBD_SPEED_HIGH)
   {
-    USBD_GetString (USBD_CONFIGURATION_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_CONFIGURATION_STRING_FS, USBD_StrDesc, length);
   }
   else
   {
-    USBD_GetString (USBD_CONFIGURATION_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_CONFIGURATION_STRING_FS, USBD_StrDesc, length);
   }
   return USBD_StrDesc;
 }
@@ -321,11 +321,11 @@ uint8_t *  USBD_FS_InterfaceStrDescriptor( USBD_SpeedTypeDef speed , uint16_t *l
 {
   if(speed == 0)
   {
-    USBD_GetString (USBD_INTERFACE_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_INTERFACE_STRING_FS, USBD_StrDesc, length);
   }
   else
   {
-    USBD_GetString (USBD_INTERFACE_STRING_FS, USBD_StrDesc, length);
+    USBD_GetString ((uint8_t *)USBD_INTERFACE_STRING_FS, USBD_StrDesc, length);
   }
   return USBD_StrDesc;
 }