diff --git a/readme.txt b/readme.txt
index 392efdc..3a64f90 100644
--- a/readme.txt
+++ b/readme.txt
@@ -39,7 +39,7 @@
 	
 	| STS-M1	|	Water Leakage Sensor		|    GPIO ReedSwitch 		|
 	| STS-M3	|	Tank Level Sensor			|    UART UltraSonic 		|
-	| STS-M4    |   Water Flow Sensor           |    TIM ETR counting       |   	
+	| STS-M4    |   Water Flow Sensor           |    TIM2_ETR counting, PA5 |   	
 	
 	
 	| STS-P1	|	Queueing length Sensor		|    IW6843 				|