DIY

Everyone knows that yogurt is a very better-for-you product, plus it’s delicious. There is a short story under the cut about how I decided to create a yogurt maker, some pictures and a sketch.

Wandering in the vast expanses of the Internet I came across such an interesting thing as a yogurt maker. My wife likes yogurt and fairly often buys it. Having read the specialized website, I was inspired. I was inspired by the very thought of easily making yogurt at home, plus it will be more health-giving than the store-brought one. Having read a few reviews and comparisons, my wife and I decided to buy “Moulinex YG230 YOGURTEO”. But oops, we couldn’t find where to buy it in our town. We were just going to place an order when it dawned upon me. What is a yogurt maker? Roughly speaking, it’s a device for keeping some definite temperature during some definite time. If it is that simple, why not make it myself? Of course! There is an arduino being on the shelf for half a year already. Guilty as charged, please forgive me, guru of microcontrollers, but I am far from it. I had neither necessity nor time to study microcontrollers programming, so I bought an arduino, just for the fun of it, twinkled a LED, put it on the shelf and forgot about it. And now I have a chance to explain to my wife “why I buy all this trash if it’s on the shelf anyway”.

Apart from the arduino I also needed a thermal sensor DS18B20 and a solid state relay. I think there’s no use in describing how to unite all of them – it has been discussed more than once on habrhabr.ru and other field-oriented websites.
I will provide just the sketch:

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The main motive for the creation of the microscope was the struggle against malaria — in the developing countries about a billion microscopic examinations of the blood samples per year have to be carried out for malaria diagnosis. A standard laboratory microscope is an expensive and fragile device. Stanford scientists have managed to construct a microscope with magnification up to the 2000x, while the cost of all the components in a mass production will be 97 cents. The microscope body is cut out and folded from a sheet of thick paper. Other components are a flat battery, a LED switch, a piece of conductive copper tape and a glass or a sapphire ball lens.

Paper microscope fits easily in your one's pocket, weighs less than ten grams, can be used for brightfield, darkfield, polarized and fluorescent microscopy, and even work as a projector. One battery lasts for 50 hours. Microscope can easily endure pretty rough usage, it can even be stepped on, it can be dropped on the floor — it can withstand anything that a piece of cardboard can withstand. The quality of the microscope image is sufficient to determine various types of infections in outdoor conditions.

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