diff --git a/aqhome/0BUILD b/aqhome/0BUILD
index a49987e..0cf98a6 100644
--- a/aqhome/0BUILD
+++ b/aqhome/0BUILD
@@ -44,6 +44,7 @@
   
   
     <headers dist="true" >
+      api.h
       serial.h
       serial_p.h
     </headers>
@@ -72,5 +73,22 @@
 
 
   </target>
+
+
+
+  <target type="Program" name="libtest" >
+    <includes type="c" >
+      $(gwenhywfar_cflags)
+      -I$(topsrcdir)
+      -I$(topbuilddir)
+    </includes>
+
+    <setVar name="local/cflags">$(visibility_cflags)</setVar>
+
+    <sources>libtest.c</sources>
+    <useTargets>aqhome</useTargets>
+    <libraries>$(gwenhywfar_libs)</libraries>
+  </target>
+
   
 </gwbuild>
diff --git a/aqhome/api.h b/aqhome/api.h
new file mode 100644
index 0000000..250b619
--- /dev/null
+++ b/aqhome/api.h
@@ -0,0 +1,50 @@
+/****************************************************************************
+ * This file is part of the project AqHome.
+ * AqHome (c) by 2023 Martin Preuss, all rights reserved.
+ *
+ * The license for this file can be found in the file COPYING which you
+ * should have received along with this file.
+ ****************************************************************************/
+
+#ifndef AQH_API_H
+#define AQH_API_H
+
+
+
+# ifdef BUILDING_AQHOME
+#  /* building AqHome */
+#  if AQHOME_SYS_IS_WINDOWS
+#    /* for windows */
+#    ifdef __declspec
+#      define AQHOME_API __declspec (dllexport)
+#    else /* if __declspec */
+#      define AQHOME_API
+#    endif /* if NOT __declspec */
+#  else
+#    /* for non-win32 */
+#    ifdef GCC_WITH_VISIBILITY_ATTRIBUTE
+#      define AQHOME_API __attribute__((visibility("default")))
+#    else
+#      define AQHOME_API
+#    endif
+#  endif
+# else
+#  /* not building AqHome */
+#  if AQHOME_SYS_IS_WINDOWS
+#    /* for windows */
+#    ifdef __declspec
+#      define AQHOME_API __declspec (dllimport)
+#    else /* if __declspec */
+#      define AQHOME_API
+#    endif /* if NOT __declspec */
+#  else
+#    /* for non-win32 */
+#    define AQHOME_API
+#  endif
+# endif
+
+
+
+
+#endif
+
diff --git a/aqhome/libtest.c b/aqhome/libtest.c
new file mode 100644
index 0000000..0fcefc7
--- /dev/null
+++ b/aqhome/libtest.c
@@ -0,0 +1,63 @@
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "aqhome/serial.h"
+
+#include <gwenhywfar/debug.h>
+#include <gwenhywfar/text.h>
+#include <gwenhywfar/gwentime.h>
+#include <gwenhywfar/buffer.h>
+
+
+
+int testRecv()
+{
+  AQH_SERIAL *sr;
+  int rv;
+  int i;
+  GWEN_BUFFER *dbuf;
+
+  fprintf(stdout, "Opening device...\n");
+  sr=AQH_Serial_new("/dev/ttyUSB0", 240);
+  rv=AQH_Serial_Open(sr);
+  if (rv<0) {
+    DBG_ERROR(NULL, "ERROR opening device (%d)", rv);
+    AQH_Serial_free(sr);
+    return 2;
+  }
+  fprintf(stdout, "Device open, waiting for packets\n");
+
+  dbuf=GWEN_Buffer_new(0, 256, 0, 1);
+  for (i=0; ; i++) {
+    uint8_t buffer[1024];
+    GWEN_TIME *ti;
+
+    fprintf(stdout, "Waiting for packet...\n");
+    rv=AQH_Serial_Recv(sr, buffer, sizeof(buffer)-1);
+    if (rv<0)
+      break;
+    ti=GWEN_CurrentTime();
+    GWEN_Time_toString(ti, "YYYY-MM-DD hh:mm:ss", dbuf);
+    fprintf(stdout, "%s: Received:\n", GWEN_Buffer_GetStart(dbuf));
+    GWEN_Text_DumpString(buffer, rv, 2);
+    GWEN_Time_free(ti);
+    GWEN_Buffer_Reset(dbuf);
+    fprintf(stdout, "\n");
+  }
+  GWEN_Buffer_free(dbuf);
+
+  AQH_Serial_Close(sr);
+  AQH_Serial_free(sr);
+  return 0;
+}
+
+
+
+int main(void)
+{
+  return testRecv();
+}
+
+
diff --git a/aqhome/serial.h b/aqhome/serial.h
index c28878c..0458653 100644
--- a/aqhome/serial.h
+++ b/aqhome/serial.h
@@ -9,7 +9,10 @@
 #ifndef AQH_SERIAL_H
 #define AQH_SERIAL_H
 
+#include <aqhome/api.h>
+
 #include <gwenhywfar/buffer.h>
+
 #include <inttypes.h>
 
 
@@ -21,19 +24,19 @@ extern "C" {
 typedef struct AQH_SERIAL AQH_SERIAL;
 
 
-AQH_SERIAL *AQH_Serial_new(const char *deviceName, uint8_t addr);
-void AQH_Serial_free(AQH_SERIAL *sr);
+AQHOME_API AQH_SERIAL *AQH_Serial_new(const char *deviceName, uint8_t addr);
+AQHOME_API void AQH_Serial_free(AQH_SERIAL *sr);
 
-uint8_t AQH_Serial_GetAddress(const AQH_SERIAL *sr);
+AQHOME_API uint8_t AQH_Serial_GetAddress(const AQH_SERIAL *sr);
 
 
-int AQH_Serial_Open(AQH_SERIAL *sr);
-void AQH_Serial_Close(AQH_SERIAL *sr);
+AQHOME_API int AQH_Serial_Open(AQH_SERIAL *sr);
+AQHOME_API void AQH_Serial_Close(AQH_SERIAL *sr);
 
-int AQH_Serial_Recv(AQH_SERIAL *sr, uint8_t *buf, int len);
-int AQH_Serial_Send(AQH_SERIAL *sr, const uint8_t *ptr, uint8_t len);
+AQHOME_API int AQH_Serial_Recv(AQH_SERIAL *sr, uint8_t *buf, int len);
+AQHOME_API int AQH_Serial_Send(AQH_SERIAL *sr, const uint8_t *ptr, uint8_t len);
 
-int AQH_Serial_SendPacket(AQH_SERIAL *sr, uint8_t destAddr, const uint8_t *ptr, uint8_t len);
+AQHOME_API int AQH_Serial_SendPacket(AQH_SERIAL *sr, uint8_t destAddr, const uint8_t *ptr, uint8_t len);
 
 
 #ifdef __cplusplus