diff --git a/LT_remote_control_box.md b/LT_remote_control_box.md
index 7fa583c..20d7f5c 100644
--- a/LT_remote_control_box.md
+++ b/LT_remote_control_box.md
@@ -13,25 +13,28 @@ https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_ter
 
 ## Pi Pico
 
+### IR RX
 IR RX TSOP2256
 datasheet: https://www.vishay.com/docs/82459/tsop48.pdf
 
-pin1 OUT - Pi Pico pin 16  
-pin2 VCC
-pin3 GND 
-
-IR TX TSAL6200 / TSAL6100
+- pin1 OUT - Pi Pico pin 16  
+- pin2 VCC
+- pin3 GND 
 
+### IR TX
+- IR TX TSAL6200 / TSAL6100 
+- PN2222A NPN transistor
+- resistor 47R
 
 ### Pi Pico pin:
 
-pin 16 - IR RX
-pin 17 - IR TX
-pin 18 - button 3
-pin 19 - button
-pin 20 - button
-pin 21 - button
-pin 22 - Red LED
-pin 26 - Green LED
-pin 27 - Blue LED
+- pin 16 - IR RX
+- pin 17 - IR TX
+- pin 18 - button 3
+- pin 19 - button
+- pin 20 - button
+- pin 21 - button
+- pin 22 - Red LED
+- pin 26 - Green LED
+- pin 27 - Blue LED