This one is a creation from David Hunt who was successful in creating a clever hack for those owners who are tired of getting up every time to open doors whenever their dog needs to go out. This one is also an important hack for those people who have more than one or two dogs or the lactating dogs with 7-8 puppies. The system is known as Pi-Rex and is a bark-activated device. 

 

 

 

Hunt was motivated to make this project as the new member of his family was causing serious sleep deprivation issues. She would bark when left outside at night and also bark early morning when left inside. Recognizing the barking pattern, any owner can make this system to let their dogs go out whenever they need to pee.A simple way of dealing with this problem is installing a timer with door strike, however, if you need something more accurate and hi-tech a Raspberry Pi system can definitely give you better options. 

 

The system includes a bark detector that has been wired with the input of Raspberry Pi system that helps it in detecting barks. A motor driver circuit is driven to the actuator that unlatches the door along with a pulley or weight system that swings open the door whenever it is unlocked. For this project, David bought an audio detection circuit from Maplin in form of a DIY kit for 9.99 Euros. In this kit, you will get a PCB and all other components that can be soldered together to form a new system. The total time needed for this project is some 30 minutes and you will see that whenever the dog barks, LEDs would light up to indicate the activation of the system. 

 

For coding, schematics, and all other details, check out the link mentioned in the source below.