diff --git a/cube/User/Inc/logger.h b/cube/User/Inc/logger.h
index d051bdf..48dfa41 100644
--- a/cube/User/Inc/logger.h
+++ b/cube/User/Inc/logger.h
@@ -1,6 +1,8 @@
 #ifndef _LOGGER_H_
 #define _LOGGER_H_
 
+
+
 // initialize the logger, creates a ringbuffer
 void logInit();
 
@@ -9,7 +11,7 @@ void logFree();
 
 // log a message, make sure it is a null-terminated string
 // return value can be ignored, it is only used in test
-int logMsg(char *msg);
+int logMsg(const char *format, ...);
 
 // reads the ringbuffer and transfers data to output channel
 // call this from the idle-loop
diff --git a/cube/User/Src/logger.c b/cube/User/Src/logger.c
index 62627cf..5cdcffa 100644
--- a/cube/User/Src/logger.c
+++ b/cube/User/Src/logger.c
@@ -8,10 +8,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-
-#ifdef TEST
+#include <stdarg.h>
 #include <stdio.h>
-#endif
 
 
 #include <logger.h>
@@ -20,8 +18,10 @@
 
 #ifdef TEST
 #define LOGBUFFER_SIZE 32
+#define MSGBUFFER_SIZE 16
 #else
 #define LOGBUFFER_SIZE 1024
+#define MSGBUFFER_SIZE 64
 #endif // TEST
 
 
@@ -60,18 +60,25 @@ static void flashGreenLed(void *handle) {
 }
 #endif // TEST
 
-int logMsg(char *msg) {
+int logMsg(const char *format, ...) {
     int res = -1;
+    char msgBuffer[MSGBUFFER_SIZE];
 
-    if (-1 == (res = ringbufferPut(&logBuffer, (uint8_t*) msg, strlen(msg)))) {
+    va_list vl;
+    va_start(vl, format);
+    int vcnt = vsnprintf(msgBuffer, MSGBUFFER_SIZE, format, vl);
+    va_end(vl);
+
+    if (vcnt < MSGBUFFER_SIZE) {
+        if (-1 == (res = ringbufferPut(&logBuffer, (uint8_t*) msgBuffer, strlen(msgBuffer)))) {
 #ifndef TEST
-        // blink the green light or so
-        flashGreenLed(NULL);
-        schAdd(flashGreenLed, NULL, 100, 0);
+            // blink the green light or so
+            flashGreenLed(NULL);
+            schAdd(flashGreenLed, NULL, 100, 0);
 #else
-        printf("\n*** green blink ***\n");
+            printf("\n*** green blink ***\n");
 #endif // TEST                
+        }
     }
-
     return res;
 }
diff --git a/cube/User/Src/main2.c b/cube/User/Src/main2.c
index ef6ed53..c599b95 100644
--- a/cube/User/Src/main2.c
+++ b/cube/User/Src/main2.c
@@ -24,7 +24,9 @@ void my_errorHandler() {
 }
 
 void helloWorld(void *handle) {
-    logMsg("Hello World\n\r");
+    static uint32_t cnt = 0;
+    logMsg("Hello World, %ld\n\r", cnt);
+    cnt++;
 }
 
 void helloMeterbus(void *handle) {
@@ -36,7 +38,7 @@ void my_setup_2() {
     led(RED, OFF);
     led(GREEN, ON);
 
-    schAdd(helloWorld, NULL, 0, 5000);
+    schAdd(helloWorld, NULL, 0, 1000);
     schAdd(helloMeterbus, NULL, 0, 10000);
 
 }