Once upon a time there was a boy who, despite thirty began, starts his adventure with modeling. Once his first foam model consumed bottle of resin and demanded retirement, Santa brought him for Christmas a real RC glider. Beautiful! The glossy laminate fuselage and veneer wings. Glider required a lot of work: installing servos and towing hook, painting wings, balancing. Once it was finished and could go out into the meadow, the superior excellence rewarded all that work by giving a lot of fun.
At that time, there still wasn't a small and efficient 3-phase motors and Li-polymer batteries. Small fuselage capacity and limited manual skills did not allow rework to electroglider. I had a rubber hall, which allowed haul up the glider on a limited altitude. There was a question on what is the altitude and how to shoot a rubber to pull it higher?
At that time I could feel the almost magical, invisible force pulling the model up - the thermals. With all the invisible stuff is a problem, because it's hard to use something you can't see. Also current is invisible, but can be measured with the multimeter above its voltage and current. With a better tool, the oscilloscope, you can even watch how it to change in time and capture on the screen very briefly changes. Similarly, radio waves, with the receiver you can hear them and having a better tool the spectrum analyzer - you can see on screen power, frequency, width broadcasting. Without the tools, these events are like magic.
The same goes for thermals. You can find out about the fact that there are, like you can check voltage of the LiPo pack using your tongue, but to find thermals, rate them and keep model in it you need the tool, or many years of experience.
In those days, such tool was available abroad. It cost a lot and did things in a way that I already knew or I could at least imagine. A couple of things including radio transmission was out of my reach, but if they can whether I am worse?
Then on my horizon appeared goal - I want to make my own variometer. Then I did it subconsciously, but now I know that having a goal is pretty damn serious. With the goal, even distant and seemingly unattainable, with a little perseverance you can reach it. Without the goal, you can go through life without achieving anything.
The next few years was a series of investments in the components, the lot of work put into the software measurement, registration, building a sound messages and take the next hardware versions. The first flying versions were able to record the altitude, temperature and battery voltage. After the flight I could already draw some conclusions. Then the variometer began to speak but still could not measure the rate of climb. All I tried to do was not sensitive enough. This experience is highly depressing, but then I can not give up!
Then came the idea of using computer simulation. New experience for me, but it gave the opportunity to test the measuring circuits without using a soldering iron and build another device models. I put a lot of work to calculate and build a mathematical model of variometer, but it gave effect. I knew what I have to change in order to reach the required parameters. In conjunction with efficient simulation rather quickly managed to achieve the required sensitivity. Along the way, there was still a lot of unforeseen events that had to be taken into account, but it's been downhill skiing. Hardware version 1.5 was already with working variometer and radio, I could fly with it.
To make a product suitable to sell, I had to put another 2 years of work and more or less annual salary. It's easy to give up having prospect of such expenditure, fortunately not all appear at once. The growing pressure from your hand supported me, and the shame of failure blocked a chance to escape.
Thus, five years ago, in 2007, there is a commercial version, competing for foreign devices.
Later, there was only work, work and work on the project, the gradual recovery from debt and build the company that you know today.
To celebrate the variometer's fifth birthday, I wish you: have a dream and sets itself ambitious goals. This is the way you should go.
For those who have a different goal than building your own, better variometer, I can offer the SkyAssitant in birthday price 199 €.