diff --git a/README.md b/README.md
index bd348b5..3152575 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,8 @@ To unifiy escape room 2.0 development, *ArduinoProps library* provides a simple
     PROG -> request a control program
 ```
 
+![Prop protocol](help/Prop-Protocol.png)
+
 ### Handling long message seamlessly and efficiently  
 MQTT standard limitations are far above what we need:
 - maximum topic length 65,536 bytes (64k)
diff --git a/help/Prop-Protocol.png b/help/Prop-Protocol.png
new file mode 100644
index 0000000..7260836
Binary files /dev/null and b/help/Prop-Protocol.png differ