diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 219a2eb..b1e6ac3 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_executable(cmmk-test test.c)
 add_executable(cmmk-debug debug.c)
+add_executable(cmmk-find-code findcode.c)
 
 find_package(HIDAPI QUIET COMPONENTS libusb)
 add_definitions(-DCMMK_TRACE)
@@ -7,9 +8,11 @@ add_definitions(-DCMMK_TRACE)
 IF (WIN32)
 	target_link_libraries(cmmk-test cmmk_shared)
 	target_link_libraries(cmmk-debug cmmk_shared)
+	target_link_libraries(cmmk-find-code cmmk_shared)
 ELSE()
 	target_link_libraries(cmmk-test cmmk_shared hidapi-hidraw)
 	target_link_libraries(cmmk-debug cmmk_shared hidapi-hidraw)
+	target_link_libraries(cmmk-find-code cmmk_shared hidapi-hidraw)
 ENDIF()
 
 target_include_directories(cmmk-test PRIVATE
@@ -20,11 +23,16 @@ target_include_directories(cmmk-debug PRIVATE
 	${libcmmk_SOURCE_DIR}/include
 	${CMAKE_CURRENT_SOURCE_DIR})
 
+target_include_directories(cmmk-find-code PRIVATE
+	${libcmmk_SOURCE_DIR}/include
+	${CMAKE_CURRENT_SOURCE_DIR})
+
+
 IF (NOT WIN32)
-	install(TARGETS cmmk-test cmmk-debug
+	install(TARGETS cmmk-test cmmk-debug cmmk-find-code
 		CONFIGURATIONS Debug
 		RUNTIME DESTINATION bin/debug)
-	install(TARGETS cmmk-test cmmk-debug
+	install(TARGETS cmmk-test cmmk-debug cmmk-find-code
 		CONFIGURATIONS Release
 		RUNTIME DESTINATION bin/release)
 ENDIF()
diff --git a/test/findcode.c b/test/findcode.c
new file mode 100644
index 0000000..dcb517b
--- /dev/null
+++ b/test/findcode.c
@@ -0,0 +1,156 @@
+/*
+ * This file is part of libcmmk.
+ *
+ * libcmmk is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * libcmmk is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with libcmmk.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <libcmmk/libcmmk.h>
+
+#ifdef WIN32
+#include <windows.h>
+#else
+#include <unistd.h> /* usleep() */
+#include <signal.h>
+#include <time.h> /* do we need this? */
+#endif
+
+#include <string.h> /* memset() */
+#include <stdio.h>
+#include <stdlib.h>
+
+int g_stop = 0;
+
+#ifdef WIN32
+BOOL WINAPI ctrl_handler ( DWORD ctrlType )
+{
+    /* We only care about ctrl+c events. */
+    if ( ctrlType == CTRL_C_EVENT ) {
+        g_stop = 1;
+        return TRUE;
+    }
+    return FALSE;
+}
+#else
+static void interrupted ( int sig )
+{
+    ( void ) sig;
+
+    g_stop = 1;
+}
+#endif
+
+void sleep_ms ( int ms )
+{
+#ifdef WIN32
+    Sleep ( ms );
+#elif _POSIX_C_SOURCE >= 199309L
+    struct timespec t;
+    t.tv_sec = ms / 1000;
+    t.tv_nsec = ( ms % 1000 ) * 1000000;
+    nanosleep ( &t, NULL );
+#else
+    usleep ( ms * 1000 );
+#endif
+}
+
+int main ( int argc, char** argv )
+{
+    ( void ) argc;
+    ( void ) argv;
+
+    struct cmmk state = {0};
+
+    int product;
+
+    if ( cmmk_find_device ( &product ) != 0 ) {
+        return 1;
+    }
+    printf ( "Product: %s\n", cmmk_product_to_str ( product ) );
+
+    if ( cmmk_attach ( &state, product, -1 ) != 0 ) {
+        return 1;
+    }
+    printf ( "Layout: %s\n", cmmk_layout_to_str ( state.layout ) );
+
+#ifdef WIN32
+    SetConsoleCtrlHandler ( ctrl_handler, TRUE );
+#else
+    signal ( SIGINT, interrupted );
+#endif
+
+    g_stop = 0;
+
+    struct rgb offcolor = MKRGB ( 0x000000 );
+    struct rgb color1 = MKRGB ( 0x00ff00 );
+    struct rgb color2 = MKRGB ( 0xff0000 );
+    cmmk_set_control_mode ( &state, CMMK_MANUAL );
+    cmmk_set_all_single ( &state, &offcolor );
+
+    int max = 200;
+    int start = 0;
+    int c;
+
+    if ( argc > 1 ) {
+        start = atoi ( argv[1] );
+    }
+    if ( argc > 2 ) {
+        max = atoi ( argv[2] );
+    }
+
+    if ( start > max ) {
+        fprintf ( stderr, "Start (%i) has to be smaller than max (%i) value\n", start, max );
+    }
+
+    int step = ( max-start+1 ) /2;
+    while ( start < max ) {
+        fprintf ( stdout, "Checking from %i to %i\n", start, max -1 );
+        for ( int i = start; i < max; ++i ) {
+            if ( i < start + step ) {
+                //first half
+                cmmk_set_single_key_by_id ( &state, i, &color1 );
+            } else {
+                //second half
+                cmmk_set_single_key_by_id ( &state, i, &color2 );
+            }
+        }
+        fprintf ( stdout, "Is your key illuminated in green? (%i to %i)? [y/N] ", start, start + step - 1 );
+        fflush ( stdout );
+        do {
+            c = getchar();
+        } while ( !g_stop && c != 'y' && c != 'Y' && c != 'n' && c != 'N' );
+        if ( g_stop ) {
+            goto finish;
+        }
+        if ( c == 'y' || c == 'Y' ) {
+            max = start + step;
+            fprintf ( stdout, "Got it\n" );
+        } else {
+            //next interval
+            start += step;
+            fprintf ( stdout, "It is in the other half!   \n" );
+        }
+        cmmk_set_all_single ( &state, &offcolor );
+        //half the interval
+        if ( step == 1 ) {
+            break;
+        }
+        step = ( step + 1 ) / 2;
+    };
+    fprintf ( stdout, "\nYour key is %i\n", start );
+
+finish:
+    cmmk_set_control_mode ( &state, CMMK_FIRMWARE );
+    cmmk_detach ( &state );
+
+    return 0;
+}
diff --git a/test/test.c b/test/test.c
index 849a4a9..9f76662 100644
--- a/test/test.c
+++ b/test/test.c
@@ -103,9 +103,9 @@ int test_multilayer(struct cmmk *dev)
 	cmmk_set_control_mode(dev, CMMK_EFFECT);
 
 	cmmk_switch_multilayer(dev, 1);
-		cmmk_set_effect_fully_lit(dev, &f);
-		cmmk_set_effect_wave(dev, &w);
-		cmmk_set_effect_raindrops(dev, &r);
+	cmmk_set_effect_fully_lit(dev, &f);
+	cmmk_set_effect_wave(dev, &w);
+	cmmk_set_effect_raindrops(dev, &r);
 	cmmk_switch_multilayer(dev, 0);
 
 	cmmk_set_multilayer_map(dev, &map);