diff --git a/firmware/basic/Makefile b/firmware/basic/Makefile
index c7fe8c1..7bbd1bb 100644
--- a/firmware/basic/Makefile
+++ b/firmware/basic/Makefile
@@ -14,6 +14,7 @@ OBJS += crc.o
 OBJS += menu.o
 OBJS += xxtea.o
 OBJS += ecc.o
+OBJS += byteorder.o
 
 LIBNAME=basic
 
diff --git a/firmware/basic/byteorder.c b/firmware/basic/byteorder.c
new file mode 100644
index 0000000..9099c56
--- /dev/null
+++ b/firmware/basic/byteorder.c
@@ -0,0 +1,9 @@
+#include <stdint.h>
+
+void uint32touint8p(uint32_t v, uint8_t *p)
+{
+    *p++ = (v>>24)&0xFF;
+    *p++ = (v>>16)&0xFF;
+    *p++ = (v>> 8)&0xFF;
+    *p++ = (v>> 0)&0xFF;
+}
diff --git a/firmware/basic/byteorder.h b/firmware/basic/byteorder.h
new file mode 100644
index 0000000..ba1073e
--- /dev/null
+++ b/firmware/basic/byteorder.h
@@ -0,0 +1,5 @@
+#ifndef _BYTEORDER_H_
+#define _BYTEORDER_H_
+void uint32touint8p(uint32_t v, uint8_t *p);
+
+#endif