WIP: Software for E1 mux/demux
diff --git a/src/crc4itu.h b/src/crc4itu.h
new file mode 100644
index 0000000..ba8e79a
--- /dev/null
+++ b/src/crc4itu.h
@@ -0,0 +1,3 @@
+#pragma once
+
+uint8_t crc4itu(uint8_t crc, const uint8_t *data, unsigned int len);