diff --git a/src/modules/protocol.cpp b/src/modules/protocol.cpp
index a230fd3..2b60404 100644
--- a/src/modules/protocol.cpp
+++ b/src/modules/protocol.cpp
@@ -51,11 +51,11 @@ DecodeStatus Protocol::DecodeRequest(uint8_t c) {
             return DecodeStatus::Error;
         }
     case RequestStates::Value:
-        if (c >= '0' && c <= '9') {
+        if (IsDigit(c)) {
             requestMsg.value *= 10;
             requestMsg.value += c - '0';
             return DecodeStatus::NeedMoreData;
-        } else if (c == '\n') {
+        } else if (IsNewLine(c)) {
             rqState = RequestStates::Code;
             return DecodeStatus::MessageCompleted;
         } else {
@@ -64,7 +64,7 @@ DecodeStatus Protocol::DecodeRequest(uint8_t c) {
             return DecodeStatus::Error;
         }
     default: //case error:
-        if (c == '\n') {
+        if (IsNewLine(c)) {
             rqState = RequestStates::Code;
             return DecodeStatus::MessageCompleted;
         } else {
@@ -107,7 +107,7 @@ DecodeStatus Protocol::DecodeResponse(uint8_t c) {
             return DecodeStatus::Error;
         }
     case ResponseStates::RequestValue:
-        if (c >= '0' && c <= '9') {
+        if (IsDigit(c)) {
             responseMsg.request.value *= 10;
             responseMsg.request.value += c - '0';
             return DecodeStatus::NeedMoreData;
@@ -135,11 +135,11 @@ DecodeStatus Protocol::DecodeResponse(uint8_t c) {
             return DecodeStatus::Error;
         }
     case ResponseStates::ParamValue:
-        if (c >= '0' && c <= '9') {
+        if (IsDigit(c)) {
             responseMsg.paramValue *= 10;
             responseMsg.paramValue += c - '0';
             return DecodeStatus::NeedMoreData;
-        } else if (c == '\n') {
+        } else if (IsNewLine(c)) {
             rspState = ResponseStates::RequestCode;
             return DecodeStatus::MessageCompleted;
         } else {
@@ -148,7 +148,7 @@ DecodeStatus Protocol::DecodeResponse(uint8_t c) {
             return DecodeStatus::Error;
         }
     default: //case error:
-        if (c == '\n') {
+        if (IsNewLine(c)) {
             rspState = ResponseStates::RequestCode;
             return DecodeStatus::MessageCompleted;
         } else {
diff --git a/src/modules/protocol.h b/src/modules/protocol.h
index d55e655..dea8ea1 100644
--- a/src/modules/protocol.h
+++ b/src/modules/protocol.h
@@ -151,6 +151,13 @@ private:
 
     ResponseStates rspState;
     ResponseMsg responseMsg;
+
+    static bool IsNewLine(uint8_t c) {
+        return c == '\n' || c == '\r';
+    }
+    static bool IsDigit(uint8_t c) {
+        return c >= '0' && c <= '9';
+    }
 };
 
 } // namespace protocol