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Showing posts with the label DIY

Build those noise cancelling headphones

So, here's another DIY Let me start by putting the cart before the horse. I shall start with the credits. This project was done while I was working on my Electronics Design Lab, along with my friends, Srujan M and Indrasen Bhattacharya. The work would not have been possible without the generous help received from the staff at Wadhwani Electronics Laboratory, who ensured that the only thing we did right was to leave the lab on time. This project would also not have been possible without the guidance of our dear and learned professors. It would probably have just about become additional dead weight on the head. Enough with the credits, now, I need to dive right into noise cancellation and how it works. The essence of sound is a pressure wave. The pressure wave, when incident on the eardrum sets into motion the complex mechanisms inside the ear, and after a long path, rather like the Cog advertisement, ends up making some nerves vibrate. The nerves send electrical signals to the b...

Making a simple temperature sensor

After a whole lot of posts written out of sheer frustration, here is something you can really do. In this post, I explain how to build a simple temperature sensor. The temperature sensor is a LM35 chip. This is a easy to use 3 pin package. The pins are Vcc, Gnd and Vout. The output voltage (in millivolts) is the temperature in degrees centigrade * 10. I am using an Atmel ATmega8 micro-controller. There really is no specific reason for choosing this micro-controller, except for easy availability (I had one) and previous experience. The third and last major component is the LCD display for displaying the temperature. Now for some quick calculations. My temperature shall not in general exceed 100C. A diode drops 0.6V when it is on. Putting two diodes in series, I get an almost constant voltage of 1.200V. I have a 10 bit ADC. Hence, the temperature in Celsius*10 is ADC*1200/1024, or (ADC*1200)>>10. The final touch is a simple push-button for cycling through day average, day maximum a...