diff --git a/inc/protocol.h b/inc/protocol.h
--- a/inc/protocol.h
+++ b/inc/protocol.h
@@ -35,6 +35,7 @@ typedef enum {
     RELAYDRIVE = 0X02,
     WATERSENSE = 0x03,
     PROTOMODULE = 0x04,
+    LIGHTSENSE = 0x05,
 } protocol_device_t;
 
 typedef enum {