Tuesday, 22 July 2014

Tweeting Microwaves - Because you can!


Last month in the midst of procrastinating for exams, I thought to myself... What does the world need? And then it came to me... A twitter enabled microwave!

For the impatient, here is a video of it in action.

Here is a demo twitter account that I used to test the app:



Almost every microwave makes a beep sound when you press its buttons. Also, when the microwave is finished cooking, it usually beeps 2-5 times. The idea behind the app is that by listening to the beeps of the microwave, it can then infer what is going on within the microwave.

All of the work of the app is done within the frequency domain. When the app first boots up, it asks you to record the sound of your microwave beep. Then, the application performs a FFT on that beep to determine what it's characteristic frequency is. The app is then constantly performing an FFT on the input audio, looking for the target beep frequency.

When you put your food in the microwave, you press a few buttons to input the time, and the last button that you press is start. So if I am going to cook something for five minutes, I will press 5-0-0-start. Then five minutes after pressing start, the microwave will beep to indicate that it has completed cooking the food. All the app has to do is measure the length of time between the start beep and the first finish beep. From this it can determine how long the food was cooking for.

When you press the first button on the microwave, in this case five, the app takes a photo of you and your food. When the app decides that you are finished cooking the food, it posts the picture to twitter along with how long your food has been cooking for.