BBC micro:bit
Feline Detection System
Introduction
This project is a simple prototype for a Feline Detection System (FDS). The FDS is meant to detect the presence of a cat.
Project Requirements
- You will need a micro:bit.
- You can do this from USB power but it will be easier to set up with an optional battery pack.
- You will need two cables with crocodile clip connectors.
- You will need to make two electrical contacts for the test subject to touch. Tin foil is my product of choice.
You need to choose a suitable test subject. Here was my willing participant,
You must respect your test subject and show due regard for his/her safety.
Felis Catus is not generally known to work for free. You will need something to interest the subject. A supply of cat treats may be also be required.
Clip a crocodile from pin 0 to one piece of foil. Clip the other one to GND.
Python Program
A simple program is used. All that happens is that an image is displayed on the LED matrix when the cat touches both contacts at the same time.
from microbit import * while True: if pin0.is_touched(): display.show(Image.GHOST) else: display.clear() sleep(10)
Results
Bait the trap and then wait. The test subject places his back legs on the first electrical contact. As he eats the cat treats, he makes a connection to the second piece of foil with his front paws or with his tongue. The light goes on to register the presence of a cat.
Challenges
- Obviously, there could be more action when the cat is detected. Cats react differently to buzzer noises. Some are captivated by melodies, some don't like it at all.
- Notice the way that the sensor is designed. Two conductive pads are placed close enough together so that a living being can complete the circuit through natural movement. Place the pads so that a footstep would complete the circuit and you have a stomp pad. Anything that touches both pads simultaneously is going to set off the switch. Experiment away.