diff --git a/Orange-Pi-GPIO-pins.md b/Orange-Pi-GPIO-pins.md
index 346b20f..ca558d1 100644
--- a/Orange-Pi-GPIO-pins.md
+++ b/Orange-Pi-GPIO-pins.md
@@ -90,6 +90,10 @@ so for enabling PG7 that is pin 40 on the physical header can be used
 
 Then you can run `echo "1" >/sys/class/gpio/gpio2/value` to turn it on and `echo "0" >/sys/class/gpio/gpio2/value` to turn it off.
 
+You need to use a VCC3 pin and an IO pin for this. Refer to this diagram (Page 15): http://linux-sunxi.org/images/7/7e/ORANGE_PI-ONE-V1_1.pdf
+
+I used pin 2 for VCC3 and pin 22 for IO.
+
 https://stackoverflow.com/questions/46463724/accessing-gpio-on-orangepi-pc-plus-h3-on-armbian-3-4-113-and-newer
 
 https://diyprojects.io/orange-pi-onelite-tutorial-use-gpio-python-pinouts/