As I developed the device, from idea to production. Part 1

One day, the head of the company where I worked for a long time was several hours late for a meeting. For a punctual person, this lateness was an extraordinary event. It turned out that the hot water stand had broken through his house in the morning, and it was only by a happy coincidence that at that moment someone was near. It is clear that if this person were not in the right place at the right time, they would flood the apartment and the neighbors.

By the time the market (2006-2007), there were already systems to prevent water leakage. However, these systems did not do the most important thing - they did not inform the owner about the “trouble” that had occurred. That is, such systems can locate a leak in their apartment, but “go beyond” and report that neighbors fill the apartment from above, such a system was simply incapable. What can we say about other problems, such as ignition, or penetration into the apartment of an unauthorized person, or about other unpleasant opportunities.
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So the idea was born to make an information device, a kind of “guard”, who will inform the owner on the phone about some events occurring in his absence in the apartment.

I considered the rough cost of the device. Then, using the “corridor” survey, estimated the approximate cost of such a device on the market. Yeah, income is, then there is the right to life.

After writing a preliminary business plan, it became obvious that there wasn’t enough money to implement this project, and it’s stupid to start doing something without proper funding. From acquaintances, no one wanted to risk "acquired by overwork." Unsuccessful attempts were made to attract Western capital. Russian “venture” funds and “business angels” were interested in other, incomprehensible nano-projects, and they did not dare to allocate several tens to hundreds of thousands of dollars, or simply did not want to.

You can say by chance, in early 2010, I went to work in a new dynamic company, which welcomed my idea and helped bring it to life. Thus was born the project MT9000 .



Currently, the MT9000 functionality includes support for 4 2.4GHz wireless multifunction sensors, each of which can detect water leakage, opening and closing of something (entrance door, cabinet door, interior doors, etc.) and high temperature.





In addition, the base unit MT9000 detects 220V electricity outage and explosive concentration of household gas. About all these troubles, the user receives messages in the form of SMS.

I will dwell on the technical details of the project.

About choosing wireless technology:

We all exist in space with radio waves (sound, radio, WiFi, BlueTooth, GSM, CDMA, microwave, radiation from Fukushima and others). The proper operation of the radio spectrum available to us is strictly monitored by state structures. Any equipment that receives or radiates radio waves, must necessarily obtain permission to use the corresponding frequencies (or rather, the manufacturing company receives permission, but we will not be childworms).

The reason for this is not only the desire to properly distribute radio frequencies, but also the intention of exKGB and military services to keep everything under their control - after all, these services take care of state security. If each person will be able to emit uncontrolledly radio waves of one frequency or another, this could damage the country's defense capability. Or else chaos in the frequency spectrum will simply begin; from this side, control is really needed.



In order not to swear each time to coordinate issues with the military, worldwide, for civilian exploitation, common, unlicensed, so-called ISM frequency bands were allocated. ISM frequencies (above the FM band) can be divided into several - 433 MHz, 868 MHz and 2.4 GHz.

The range of 433 MHz is the most noisy, it is very fond of using Chinese colleagues and car alarms. The size of the antenna in this range with a thirty-centimeter ruler. The 868 MHz band is already much better, but it has some peculiarities in the area of ​​a single standard, which make it difficult to use them in different countries even within the EU.

Uniform standardization of the frequency band 868.6-868.7 MHz in European countries:



Moreover, systems based on 868 MHz and designed for European countries are not suitable for use within the Russian Federation ( source ).

Permitted European frequencies 868.6-868.7 MHz



In Russia, the unlicensed frequency band is different: 868.0 - 868.2 MHz



As a result, the choice was made in favor of the 2.4GHz ZigBee standard because this standard was ideally suited for three reasons:

- First, this wireless technology is allowed for use in European and American clinics, which means that it is assumed to be safe for human health;

- Secondly, in this standard it is possible to realize a long time of sensor operation from a battery;

- And thirdly, the device assembled on this technology can be easily put together with the antenna and the battery in a matchbox .





The article turned out great, I decided to split it into several parts. The continuation will be in the evening or tomorrow - and it will be easier for you to read, and I will read it again. In the meantime, you can get acquainted with other gadgets Master Kit .

UPD . And here is the second part

UPD 2 . At the request of colleagues from MasterKit, I publish an announcement of cooperation with the authors:

We offer representatives of the habrasoobshchestvo cooperation with those who like all sorts of gadgets, and who can describe them in such a way that the soul first folds and then turns around so that everything is clear and intelligible. There are a couple more criteria. On the conditions of cooperation with the authors can be found here .