diff --git a/bbn_m5atomS3_lite_limit_switch/README.md b/bbn_m5atomS3_lite_limit_switch/README.md
index c8b615d..a726ee4 100644
--- a/bbn_m5atomS3_lite_limit_switch/README.md
+++ b/bbn_m5atomS3_lite_limit_switch/README.md
@@ -17,3 +17,6 @@ $BBXDR,S,0,,LIMIT_CUR*63
 M5Stack Limit Switch
 
 https://shop.m5stack.com/products/limit-switch-unit
+
+Used for detecting a hatch state (open/closed), etc
+