22 lines
1.3 KiB
Markdown
22 lines
1.3 KiB
Markdown
|
This device is designed to repel cats.
|
||
|
|
In my case, it is used to scare it away from my fridge, before it opens and empties it.
|
||
|
|
|
||
|
|
It will first detect the presence and then emit ultrasounds.
|
||
|
|
|
||
|
|
This device uses an Arduino Nano 3.0 board with an Atmel ATmega328P micro-controller.
|
||
|
|
A HC-SR501 PIR motion detector in repeat mode is connected to 5V, GND, and D4.
|
||
|
|
When motion is detected (the cat is approaching) a light barrier is switched on.
|
||
|
|
A E18-D80NK is used as light barrier.
|
||
|
|
It is connected between 5V and D5.
|
||
|
|
The signal pin is connected to D6.
|
||
|
|
When the light barrier is broken (the cat is in front of the fridge) a loud (annoying) ultrasonic sound (24-25 kHz, outside the human hearing range) is emitted (using PWM).
|
||
|
|
To make noise a piezoelectric element (without oscillator) is connected between D9 and D10.
|
||
|
|
When the switch is released (the cat opened the fridge) an alarm is sounded (4-5kHz, audible by humans) until it the door (thus switch) closed.
|
||
|
|
A button switch is connected between GND and D3, and placed on the door of the fridge.
|
||
|
|
|
||
|
|
The firmware is available in the **firmware** directory.
|
||
|
|
To flash it, use `make`.
|
||
|
|
For a more verbose version, use `make debug` (after `make clean` if `make` has been used previously).
|
||
|
|
Debug messages are then sent over the serial port.
|
||
|
|
The code is well commented for more information.
|