Developers Club geek daily blog

Night, street, LED, drugstore

2 years, 3 months ago
It is the third post from series? I will not saw yet, I will not calm down?. (The first? about the laser, the second? about the stun gun)

In 1899 the first manual small lamp (in the kartonovy body), kubsat by DIY kilowatt (equivalent) small lamp, mega-small lamp on LEDs for 3000 rubles (sic has been created!) (provided for cut by green-laser.ru shop).

The Wired log in 2012 in article devoted to the 50 anniversary of creation of LED very strongly has mixed the facts and has incorrectly specified? paternity?. So who father of LEDs?

For now I collected the facts, the childhood and how we did the first engineering attempts was remembered. Usually they occurred after we crowd have watched the movie with Bruce Li (Michael Dudikov or Cynthia Rotrok) in video salon for the Soviet ruble (who for some reason always were in cellars). Having bought the battery? Planet? for 30 kopeks and having unscrewed bulb from parent small lamp, we started assembly. Was to buy small lamp not abruptly, abruptly was to collect the sword of Jedi. And still slope was measured by color of insulating tape.

History of LEDs, assembly instruction of kilowatt lamp and traditional cut

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The motion sensor for switching of radio stations? part II

2 years, 3 months ago
Hi, Habr! Today? continuation of the improvised cycle of detailed posts for beginners. In last post we have taken ready set of the radio designer about Arduino and ultrasonic range finder in order that not only to combine them, and to have opportunity to configure radio? one left?, but also to understand in? Arduinostroyeniya? from scratch. If you have only Arduino and the sensor, you too can try something to collect from this post, but, probably, stop after configure quite good such ultrasonic ruler? that too it is good. I wanted to go further and to put the sensor on the expansion card for creation of the ready device. Here is how it at me left.


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The panel for photographing with geotags on the basis of LinkIt One

2 years, 3 months ago
The will of destiny of me into hands fell sample of rather interesting payment of LinkIt One from Mediatek. It is the single board computer with impressive set of the periphery prepared for use in the projects connected with wearable devices and IoT.

To receive? the fighting? experience with this controler we have developed the simple panel which is connected to the SLR camera, does pictures and writes shooting point coordinates.

In this article I will tell about the turned-out device and I will share our impressions of work with LinkIt One.


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Training on STM32 in masses

2 years, 3 months ago

Small background


I am the next graduate of certain Moscow higher education institution (I will not specify what, but ordinary). Half a year ago we were told that it is time to write the diploma. At that time I have only just started mastering microcontrollers and it was given me not that it is hard, but with scratch which makes the refrigerator when you, alone, try to shift accurately it, without having damaged precious laminate (in my case linoleum).

My training has begun when I have become interested in subject of microcontrollers and the engineer at whom has taken an interest about them two years ago, has given out me payment 300kh200mm and has told that in it there is STM32F217ZGT6 controler and on this payment there is all necessary for training.? Generally, you will master it? all the rest will seem hogwash? (he, however, has not told that for blinking by LED SPI about which at that time I did not even hear should configure). Later three not really strained month of incorporeal attempts, awareness of weakness of skills of programming and huge number of the read articles it was necessary nevertheless will fork up on STM32VLDISCOVERY and in the way of copying of programs and experiments with them business at last has gone, but all the same slowly.

In one and a half years has managed to work as the developer, looked for vacancies where work with STM32 (as I consider that now is the most perspective microcontrollers of the class), has picked up experience and when business has reached the diploma, has remembered the sore callosities. The idea with subject has come instantly:? Debug payment on STM32 and (full-fledged) training course (for the smallest) to it?.

Yes, I know, I know, from many engineers heard, what with subject? debug payment?? be I the teacher, I would fill up you on protection?, but nevertheless I consider, any idea has the right for life so everything to whom it is interesting, I ask to read further.

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Reverse engineering of flickering LED (+RGB)

2 years, 3 months ago
1.5 a year ago on Habré wrote reverse-inzheniringa of accidentally flickering LED about attempt. Then attempts to analyze patterns of flicker of LED as black box were not crowned with final success? however distribution of skvazhnosty intensity modulation has been set, and the emulator has been written. Lately different groups opened flickering LEDs? and it became known of their work slightly more. At last, hands and at me have reached them.

Lately it was found out, what crystals? accidental blinking?? it is a lot of versions. Photos and reflections of authors on the principle of work of similar crystals? siliconpr0n.org, cpldcpu.wordpress.com, hackaday.com. What not only that someone in detail is engaged in development and mass production such surprises it would seem to insignificant thing as flickering LED? there still is also progress/competition!

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The full guide on robotic designers from Robostation

2 years, 3 months ago


IMHO is not present in the world of the best toy, than the designer. Before emergence of the computer iron beams and plastic cubes were for me out of competition? after all from them it is possible to create the whole world without any restrictions.

Only having matured, I have learned that the meccano is top of evolution of toys on the invention (rather, even opening) which the European teachers have spent hundreds of years, step by step approaching that magnificence that we have now in each children's shop. There are no designers, would not be at me and such thirst for DIY robots.

We at Robostation have ten shops with designers and vsamdelishny roboschool where from these designers collect the real robots. Here also we will talk about it.


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Meteorological station not on Arduino, or Work with timers and interruptions of GPIO in OpenWRT

2 years, 3 months ago
Hi, Habr, did not see long ago!

At first? some important news about the project of microcomputers of Black Swift, and then we will pass to the main subject: as on microcomputer with OpenWRT to make the full-fledged built-in device.

The full-fledged built-in computer, in my opinion, is impossible without two things:
  • Support of interruptions in different occasions, including signals on GPIO inputs
  • Support of hardware timers with the good permission


Without it the considerable part of real problems of automation either is not solved in general, or is solved so that would not decide in general better. The exception is made only by the most banal? to pull the relay, svetodiodiky to pomigat, to trace pair of buttons. Everything, what demands exact timings and/or more or less fast reaction to external events? simply unrealizable without carrying out of the corresponding functionality in the external controler which the above things is able that senselessly complicates construction of the device.

That it is more surprising that at enough microcomputers on SoC Atheros AR9331 and cheaper Ralink RT5350 positioned as the built-in solutions with support in OpenWRT of these two functions everything is extremely sad. Here, of course, there is question to whom these microcomputers at such level of support are necessary? but we will leave it to be groundless.



However, if to look at it on TCP/IP, can descend and for the healthy person.

But at first? news:

  • First batch of Black Swift? in Russia it is also already sent by ruble preorders (that is made not on Kickstarter). If you at the preorder specified delivery? wait, if shipment at own expense? call in office and approach.
  • If you did not make out the preorder, but want to buy Black Swift? call in office and approach, we have very many payments over the volume of preorders. It is possible to issue delivery, but then you for obvious reasons will get up in tail of queue of preorders.
  • Certification of FCC will come to the end soon, apparently? successfully.
  • The satisfaction of beker with Kickstarter, as well as was promised, expected in June. To send to separately Russian-speaking or any else separate beker of payment we cannot on technical features of Kickstarter.
  • Slowly documentation, because of lack of time is replenished? first of all the English-speaking.
  • In particular, images of virtual computers with OpenWRT SDK and Eclipse? here (in couple of days I will update them on the fresh SDK version with our patches). Are useful to all who wants to write something under OpenWRT, but not really understands, how.


And now? to subject.

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DDA for cat

2 years, 3 months ago
There is at us in family cat by the name of the Pussycat. Young, and also cowardly and curious at the same time. The only thing, what absolutely fights off it all cowardice? this red laser speck from boshevsky range finder. She is ready to hunt for it recklessly. But. The range finder has time limit on work, batteries on it will not save enough and vly on long games with cat to waste time.

Found any automatic cat's teasers on Internet open spaces? expensively and the functionality is limited. Besides, there is no guarantee that the ray will not get on curtains, and they will not be thus subwounds completely.



Or we are not engineers-electronics engineers-arduinshchiki?! And most to collect?

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Intel Edison. Work with cloud of Intel IoT Analytics: registration and sending data

2 years, 3 months ago
cloud IoT
In article the short description of cloud of Intel IoT Analytics intended for data collection and management of devices is given. Practical work with cloud on the example of Intel Edison (Intel Edison is considered. First start).

Have passed those times when from the device ability of interaction with network was not required. Management, monitoring, have to be executed not only in close proximity now, and far off. It was required to obtain data and to manage devices through the Internet. Large number of devices is at the moment already developed and to manage them separately it has appeared rather difficult implementable task.

Unification required some universal intermediary, interfacial layer for work with the device. There was so new type of interaction of Machine-to-Cloud (M2C), interaction of the device with cloud.

The device interacts with cloud, on means of the standardized protocol. The cloud implements everything to the logician of collecting, storage, management of data. Also allows to send commands for devices for management of the Cloud is universal? glue? for the most different devices unlike at each other. The user interacts with cloud via the web interface or public API. Below the speech about cloud of Intel IoT Analytics and interaction of Intel Edison with it will go.

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My Internet of things: Guest lock

2 years, 3 months ago
There were so circumstances what there is for me one-room apartment in which I do not live, and to hand over it? in the normal way? it is not interesting to me. I have tried it to hand over through the Airbnb service, it was pleasant. And not that it is more favorable, but is exact more interestingly, process takes. But I not about it?

There was at me few times situation when I could not welcome personally the guest and hand him key. Usually in such situations it is necessary to think out different ways, from key mortgaging under rug before transfer through the concierge. I do not want to devote in the affairs of strangers and somehow not comme il faut to hide key under rug.

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