diff --git a/src/utility/spi_drv.h b/src/utility/spi_drv.h
index ab8d97d..df5e4e5 100644
--- a/src/utility/spi_drv.h
+++ b/src/utility/spi_drv.h
@@ -38,8 +38,6 @@
 	SpiDrv::waitForSlaveReady();  \
 	SpiDrv::spiSlaveSelect();
 
-static bool initialized = false;
-
 class SpiDrv
 {
 private:
diff --git a/src/utility/wifi_drv.cpp b/src/utility/wifi_drv.cpp
index bee61bf..893176d 100644
--- a/src/utility/wifi_drv.cpp
+++ b/src/utility/wifi_drv.cpp
@@ -448,7 +448,7 @@ char* WiFiDrv::getSSIDNetoworks(uint8_t networkItem)
 uint8_t WiFiDrv::getEncTypeNetowrks(uint8_t networkItem)
 {
 	if (networkItem >= WL_NETWORKS_LIST_MAXNUM)
-		return NULL;
+		return 0;
 
 	WAIT_FOR_SLAVE_SELECT();
 
@@ -473,7 +473,8 @@ uint8_t WiFiDrv::getEncTypeNetowrks(uint8_t networkItem)
 int32_t WiFiDrv::getRSSINetoworks(uint8_t networkItem)
 {
 	if (networkItem >= WL_NETWORKS_LIST_MAXNUM)
-		return NULL;
+		return 0;
+	
 	int32_t	networkRssi = 0;
 
 	WAIT_FOR_SLAVE_SELECT();