diff --git a/README.md b/README.md
index 81a2579..32908ee 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,7 @@ This is a simple, home-made door alarm based on ultrasound sensor distance measu
 The peripheral device is powered by a Raspberry Pi Pico W, with the following diagram
 
 ![door alarm peripheral device circuit diagram](circuit.png "Circuit Diagram")
+
+It works by pointing the ultrasound sensor at the door from the side, the device being placed on the doorframe. While the door is closed, the distance will be 1-5 cm, when the door opens, the side of the door will move, and the distance will be greater the more you open the door, at a 90 degree open, the distance will be the width of the door
+
+After getting the distance and comparing it to the threshold, the peripheral sends updates to the server, which may or may not send a notification to gotify based on whether the door is locked (on the server)
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