diff --git a/LT_remote_control_box.md b/LT_remote_control_box.md
index 20d7f5c..ab4a3d9 100644
--- a/LT_remote_control_box.md
+++ b/LT_remote_control_box.md
@@ -17,7 +17,7 @@ https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_ter
 IR RX TSOP2256
 datasheet: https://www.vishay.com/docs/82459/tsop48.pdf
 
-- pin1 OUT - Pi Pico pin 16  
+- pin1 OUT - Pi Pico pin 16 (pull up)  
 - pin2 VCC
 - pin3 GND