diff --git a/library.json b/library.json
index 7d7d955..8467579 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "ERa",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "description": "E-Ra by EoH. An IoT Market Enabler! It supports WiFi, Ethernet, Zigbee, Modbus, Serial. Works with boards like Arduino, ESP8266, ESP32, STM32, Raspberry Pi...",
   "keywords": "ERa, E-Ra, esp8266, esp32, stm32, raspberry-pi, http, mqtt, zigbee, modbus, sensors, control, device, smartphone, mobile, app, web, cloud, communication, protocol, iot, wifi, ethernet, serial",
   "authors":
diff --git a/library.properties b/library.properties
index a645592..eb39951 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=ERa
-version=0.9.0
+version=0.9.1
 author=EoH Ltd
 license=MIT
 maintainer=EoH Ltd <info@eoh.io>
diff --git a/src/BLE/ERaBLETranspEsp32.hpp b/src/BLE/ERaBLETranspEsp32.hpp
index 8ecb676..64d2abf 100644
--- a/src/BLE/ERaBLETranspEsp32.hpp
+++ b/src/BLE/ERaBLETranspEsp32.hpp
@@ -15,7 +15,7 @@
 #include <Encrypt/ERaEncryptMbedTLS.hpp>
 
 #define SERVICE_UUID            "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
-#define CHARACTERISTIC_UUID_TKN "cf153564-bc0d-11ed-afa1-0242ac120002"
+#define CHARACTERISTIC_UUID_TKN "cf153c1f-bc0d-11ed-afa1-0242ac120002"
 #define CHARACTERISTIC_UUID_RSP "fba737c2-9f19-4779-9ef2-9446c29d0bf5"
 #define CHARACTERISTIC_UUID_CMD "b32f3620-2846-4d1c-88aa-5dd06c0ad15e"
 
diff --git a/src/BLE/ERaNimBLETransp.hpp b/src/BLE/ERaNimBLETransp.hpp
index 1170a5e..f5fb78e 100644
--- a/src/BLE/ERaNimBLETransp.hpp
+++ b/src/BLE/ERaNimBLETransp.hpp
@@ -14,7 +14,7 @@
 #include <Encrypt/ERaEncryptMbedTLS.hpp>
 
 #define SERVICE_UUID            "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
-#define CHARACTERISTIC_UUID_TKN "cf153564-bc0d-11ed-afa1-0242ac120002"
+#define CHARACTERISTIC_UUID_TKN "cf153c1f-bc0d-11ed-afa1-0242ac120002"
 #define CHARACTERISTIC_UUID_RSP "fba737c2-9f19-4779-9ef2-9446c29d0bf5"
 #define CHARACTERISTIC_UUID_CMD "b32f3620-2846-4d1c-88aa-5dd06c0ad15e"
 
diff --git a/src/ERa/ERaApi.hpp b/src/ERa/ERaApi.hpp
index c85f84c..5b87f6c 100644
--- a/src/ERa/ERaApi.hpp
+++ b/src/ERa/ERaApi.hpp
@@ -22,18 +22,24 @@
 #endif
 
 #if defined(analogInputToDigitalPin)
-	#define ERA_DECODE_PIN(pin)		analogInputToDigitalPin(pin)
+	#define ERA_DECODE_PIN(pin)			analogInputToDigitalPin(pin)
 #else
-	#define ERA_DECODE_PIN(pin)		pin
+	#define ERA_DECODE_PIN(pin)			pin
 #endif
 
-#define ERA_INVALID_PIN				0xFF
-#define ERA_CHECK_PIN(pin)			if (pin == ERA_INVALID_PIN) { continue; }
-#define ERA_CHECK_PIN_RETURN(pin)	if (pin == ERA_INVALID_PIN) { return; }
+#define ERA_INVALID_PIN					0xFF
 
-#define ERA_DECODE_PIN_NUMBER(pin)	pin
-#define ERA_DECODE_PIN_NAME(pin) 	(((pin[0] == 'a') || (pin[0] == 'A')) ? 	\
-									ERA_DECODE_PIN(atoi(pin + 1)) : ERA_DECODE_PIN_NUMBER(atoi(pin)))
+#if defined(digitalPinIsValid)
+	#define ERA_CHECK_PIN(pin)			if (!digitalPinIsValid(pin)) { continue; }
+	#define ERA_CHECK_PIN_RETURN(pin)	if (!digitalPinIsValid(pin)) { return; }
+#else
+	#define ERA_CHECK_PIN(pin)			if (pin == ERA_INVALID_PIN) { continue; }
+	#define ERA_CHECK_PIN_RETURN(pin)	if (pin == ERA_INVALID_PIN) { return; }
+#endif
+
+#define ERA_DECODE_PIN_NUMBER(pin)		pin
+#define ERA_DECODE_PIN_NAME(pin) 		(((pin[0] == 'a') || (pin[0] == 'A')) ? 	\
+										ERA_DECODE_PIN(atoi(pin + 1)) : ERA_DECODE_PIN_NUMBER(atoi(pin)))
 
 enum ERaTypeWriteT {
 	ERA_WRITE_VIRTUAL_PIN = 0,
diff --git a/src/ERa/ERaData.hpp b/src/ERa/ERaData.hpp
index 382e27e..09c1615 100644
--- a/src/ERa/ERaData.hpp
+++ b/src/ERa/ERaData.hpp
@@ -508,20 +508,26 @@ void ERaDataBuff::onChangeHex(uint8_t value) {
 
 inline
 void ERaDataBuff::onChangeHex(const uint8_t* ptr, size_t size) {
-	if (ptr == nullptr || !size) {
+	if ((ptr == nullptr) || !size) {
 		return;
 	}
 	size_t len = size * 2 + 1;
-	char* buf = (char*)malloc(len);
-	if (buf == nullptr) {
-		return;
+	char locBuf[32] {0};
+	char* buf = locBuf;
+	if (len > sizeof(locBuf)) {
+		buf = (char*)malloc(len);
+		if (buf == nullptr) {
+			return;
+		}
 	}
+	size_t pos {0};
 	for (size_t i = 0; i < size; ++i) {
-		size_t pos = i * 2;
-		snprintf(buf + pos, size - pos, "%02x", ptr[i]);
+		pos += snprintf(buf + pos, len - pos, "%02x", ptr[i]);
 	}
 	onChange(buf);
-	free(buf);
+	if (buf != locBuf) {
+		free(buf);
+	}
 	buf = nullptr;
 }
 
diff --git a/src/ERa/ERaHelper.hpp b/src/ERa/ERaHelper.hpp
index 33babfd..fd19279 100644
--- a/src/ERa/ERaHelper.hpp
+++ b/src/ERa/ERaHelper.hpp
@@ -14,7 +14,7 @@ template <class S, typename... Args>
 class StaticRefHelper {
 public:
     static S& instance(Args&... tail) {
-        static S& _instance(tail...);
+        static S _instance(tail...);
         return _instance;
     }
 };