diff --git a/serviceinterface/ServiceInterfaceBuffer.cpp b/serviceinterface/ServiceInterfaceBuffer.cpp
index 58065994..d5ce6056 100644
--- a/serviceinterface/ServiceInterfaceBuffer.cpp
+++ b/serviceinterface/ServiceInterfaceBuffer.cpp
@@ -5,6 +5,8 @@
 // to be implemented by bsp
 extern "C" void printChar(const char*);
 
+
+
 int ServiceInterfaceBuffer::overflow(int c) {
 	// Handle output
 	putChars(pbase(), pptr());
@@ -19,16 +21,18 @@ int ServiceInterfaceBuffer::overflow(int c) {
 	return 0;
 }
 
+// custom stdio.c library for at91sam9g20 chip which does not support unsigned long
+// So I cast (unsigned int) on loggerTimes
 int ServiceInterfaceBuffer::sync(void) {
 	if (this->isActive) {
 		Clock::TimeOfDay_t loggerTime;
 		Clock::getDateAndTime(&loggerTime);
 		char preamble[96] = { 0 };
-		sprintf(preamble, "%s: | %lu:%02lu:%02lu.%03lu | ",
-				this->log_message.c_str(), (unsigned long) loggerTime.hour,
-				(unsigned long) loggerTime.minute,
-				(unsigned long) loggerTime.second,
-				(unsigned long) loggerTime.usecond /1000);
+		sprintf(preamble, "%s: | %u:%02u:%02u.%03u | ",
+				this->log_message.c_str(), (unsigned int) loggerTime.hour,
+				(unsigned int)  loggerTime.minute,
+				(unsigned int)  loggerTime.second,
+				(unsigned int)  loggerTime.usecond /1000);
 		// Write log_message and time
 		this->putChars(preamble, preamble + sizeof(preamble));
 		// Handle output