diff --git a/interface_lib/include/device3.h b/interface_lib/include/device3.h
index 79f5662..8c3a7c9 100644
--- a/interface_lib/include/device3.h
+++ b/interface_lib/include/device3.h
@@ -177,6 +177,15 @@ device3_euler_type device3_get_euler(device3_quat_type quat);
 
 device3_error_type device3_close(device3_type* device);
 
+static int32_t pack32bit_signed(const uint8_t* data);
+static int32_t pack24bit_signed(const uint8_t* data);
+static int16_t pack16bit_signed(const uint8_t* data);
+static int32_t pack32bit_signed_swap(const uint8_t* data);
+
+static int16_t pack16bit_signed_swap(const uint8_t* data);
+static int16_t pack16bit_signed_bizarre(const uint8_t* data);
+
+
 #ifdef __cplusplus
 } // extern "C"
 #endif