Bird Feeder Detector
Do you want to know when there's a bird in your bird feeder? There's a circuit for that!
This uses a PIR motion sensor that works with infrared light. And it will light up an LED when there's a bird moving inside the feeder.
A PIR sensor stores an image of the infrared light it sees. Then everytime it sees a change in this image, for example from a bird moving, its output will go HIGH for a period of time.
The Circuit
This type of sensor will only detect a change in the IR light. This means that when a bird comes into the field of view of the sensor, the LED will light up (since birds, like most other living beings, emit IR light). But if the bird manages to sit still for a bit, it will become invisible.
You can solve this by tweaking the sensitivity of the sensor and the time that the output pin stays high after a detection.
Parts List
The Layout
Basic Steps to Build:
Install the Sensor: Position the PIR motion sensor so it has a clear line of sight to the area where birds will be feeding. Make sure it is sheltered from rain and direct sunlight to avoid false triggers.
Connect the Circuit: Connect the battery to the PIR sensor's power input. Connect the output pin of the PIR sensor to the positive leg of the LED via a resistor of around 330 ohm. Complete the circuit by connecting the negative leg of the LED back to the battery's negative terminal.
Mount the LED: Place the LED at a location visible from inside your house, such as near a window, to give you a visual cue when a bird is detected.
