diff --git a/README.md b/README.md
index 67ef2b7..596f938 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,10 @@
 # Han Mqtt Adapter
 Han port pinout (RJ12):
-1. 5V
+1. 5V (max 250mA)
 2. Data request (connect to 5V to enable)
-3. GND
+3. Data GND
 4. NC
-5. DATA (TX 115200 inverted open drain)
+5. Data (TX 115200 inverted open drain)
 6. GND
 
 Add pullup resistor between Pico RX pin and 3V3