diff --git a/Core/Dallas/ds18b20_driver.c b/Core/Dallas/ds18b20_driver.c
index b6a1778..a87b63d 100644
--- a/Core/Dallas/ds18b20_driver.c
+++ b/Core/Dallas/ds18b20_driver.c
@@ -17,6 +17,9 @@ OneWire_t OW;
   */
 HAL_StatusTypeDef DS18B20_IsValidAddress(uint8_t *ROM)
 {
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
   uint8_t check_family = (*ROM == DS18B20_FAMILY_CODE);
 	/* Calculate CRC */
 	uint8_t crc = OneWire_CRC8(ROM, 7);
@@ -34,6 +37,9 @@ HAL_StatusTypeDef DS18B20_IsValidAddress(uint8_t *ROM)
   */
 HAL_StatusTypeDef DS18B20_IsValid(uint8_t *ROM)
 {
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
   if(*ROM == DS18B20_FAMILY_CODE)
     return HAL_OK;
   else
@@ -49,6 +55,11 @@ HAL_StatusTypeDef DS18B20_IsValid(uint8_t *ROM)
 uint8_t DS18B20_GetResolution(OneWire_t* OW, uint8_t *ROM) {
 	uint8_t conf;
 
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
 	/* Check valid ROM */
 	if (DS18B20_IsValid(ROM) != HAL_OK) 
     return 0;
@@ -85,6 +96,11 @@ uint8_t DS18B20_GetResolution(OneWire_t* OW, uint8_t *ROM) {
 HAL_StatusTypeDef DS18B20_SetResolution(OneWire_t* OW, uint8_t *ROM,
 		DS18B20_Res_t Resolution)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
 	uint8_t th, tl, conf;
 
 	/* Check valid ROM */
@@ -146,6 +162,11 @@ HAL_StatusTypeDef DS18B20_SetResolution(OneWire_t* OW, uint8_t *ROM,
   */
 HAL_StatusTypeDef DS18B20_StartConvT(OneWire_t* OW, uint8_t *ROM)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
 	/* Check if device is DS18B20 */
 	if(DS18B20_IsValid(ROM) != HAL_OK)
     return HAL_ERROR;
@@ -167,6 +188,9 @@ HAL_StatusTypeDef DS18B20_StartConvT(OneWire_t* OW, uint8_t *ROM)
   */
 HAL_StatusTypeDef DS18B20_StartConvTAll(OneWire_t* OW)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  
 	/* Reset pulse */
 	OneWire_Reset(OW);
 
@@ -189,6 +213,15 @@ HAL_StatusTypeDef DS18B20_StartConvTAll(OneWire_t* OW)
   */
 HAL_StatusTypeDef DS18B20_CalcTemperature(OneWire_t* OW, uint8_t *ROM, uint8_t *Scratchpad, float *Destination)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  if(Scratchpad == NULL)
+    return HAL_ERROR;
+  if(Destination == NULL)
+    return HAL_ERROR;
+  
 	uint16_t temperature;
 	uint8_t resolution;
 	int8_t digit, minus = 0;
@@ -265,6 +298,10 @@ HAL_StatusTypeDef DS18B20_CalcTemperature(OneWire_t* OW, uint8_t *ROM, uint8_t *
   */
 HAL_StatusTypeDef DS18B20_ReadScratchpad(OneWire_t* OW, uint8_t *ROM, uint8_t *Scratchpad)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
   if(Scratchpad == NULL)
     return HAL_ERROR;
   
@@ -301,6 +338,8 @@ HAL_StatusTypeDef DS18B20_ReadScratchpad(OneWire_t* OW, uint8_t *ROM, uint8_t *S
   */
 HAL_StatusTypeDef DS18B20_WaitForEndConvertion(OneWire_t* OW)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
   uint32_t tickstart = HAL_GetTick();
   
 	/* Wait until line is released, then coversion is completed */
@@ -326,6 +365,11 @@ HAL_StatusTypeDef DS18B20_WaitForEndConvertion(OneWire_t* OW)
 HAL_StatusTypeDef DS18B20_SetTempAlarm(OneWire_t* OW, uint8_t *ROM, int8_t Low,
 		int8_t High)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
 	uint8_t tl, th, conf;
 
 	/* Check if device is DS18B20 */
@@ -394,6 +438,11 @@ HAL_StatusTypeDef DS18B20_SetTempAlarm(OneWire_t* OW, uint8_t *ROM, int8_t Low,
 HAL_StatusTypeDef DS18B20_WriteUserBytes(OneWire_t* OW, uint8_t *ROM, int16_t UserBytes12,
 		int16_t UserBytes34, uint8_t UserBytesMask)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  if(ROM == NULL)
+    return HAL_ERROR;
+  
 	uint8_t ub1, ub2, conf, ub3, ub4;
   uint8_t UserByte1 = UserBytes12 & 0xFF;
   uint8_t UserByte2 = UserBytes12 >> 8;
@@ -512,6 +561,10 @@ HAL_StatusTypeDef DS18B20_WriteUserBytes(OneWire_t* OW, uint8_t *ROM, int16_t Us
   */
 HAL_StatusTypeDef DS18B20_Search(DS18B20_Drv_t *DS, OneWire_t *OW)
 {
+  if(OW == NULL)
+    return HAL_ERROR;
+  
+  
   OW->RomCnt = 0;
 	/* Search all OneWire devices ROM */
 	while(1)