Review on 🏃 Highly Efficient DIYmall HC SR501 Motion Infrared Arduino for Enhanced Arduino Projects by Tray Smith

VCC and ground connected to the 12V power supply and everything worked perfectly. There was even enough current at the 3.3V("OUT") "Trigger" pin to power the red LED directly (although it's a little dimmer than usual). Very wide sensitivity chart. The description says "<100 degrees". I thought it was over 120. At its default sensitivity, it easily fires at 8-10ft. I never adjusted it as it was the perfect distance for my needs. Hold it so that the sensor's "dome" is facing down and the adjustment screws (orange) are facing you, the left is the sensitivity, the right is the length of time the OUT pin will remain on (i.e. held ). at level 3.3 V). The minimum seems to be around 4 seconds.