Verified by electronics

Forgive me, dear Habrausers, but first a small disclaimer:

Despite the “promising” tag, things like unboxing followed by disassembling and demonstrating the insides of a quadcopter assembled on a tube Arduino and printed on a 3D printer running a 30-line script, in this post, unfortunately, will not.

The post sets out the story of the search for the most acceptable way to implement the ideas of a person who desired something strange, namely, he decided to cross his smartphone and car, and who therefore had to spend some time creating a collective farm with his own handsthe original version of the car holder for a smartphone, and at the same time find an unexpected use for things intended, it would seem, for a completely different one. Unfortunately, in that recent past, the idea to capture in all its glory, well, or at least in the photo this perverted process somehow did not occur to me (the laurels of Tinto Brass left me indifferent, moreover, to be honest, I was not sure that something will come out of this venture). One way or another, it seemed interesting to anyone, I ask for a cat.

Long and tedious foreplay. Or the story of the unsuccessful struggle for freedom from wires

The desire to use a smartphone to listen to music in the car and the subsequent searches for a way to implement this arose for me for a number of reasons. This is not a love of riding in silence (most likely it has been going on since the “happy” times of using the very elderly brainchildren of the domestic and not only the automobile industry and the permanent state of doomed readiness connected with this at any moment to hear completely spoiling the sounds of something in the next times dying in the womb of a hellish mechanism). And a rather cool attitude to listening to the radio during rush hour with its endless news, “hello” broadcasts, tons of advertising and other masterpieces of the conversational genre. And also the complete lack of desire to mess around with CD-ROMs (they and only them were allowed to be used by the regular audio system of my newly acquired car of that time).

“This is some kind of paleolithic!” I thought, and recalling my rather successful experience of using a smartphone paired with a Bluetooth headset, I was happy to connect my smartphone with a car audio system without wires. To which the latter, after a cursory study of her, said her decisive "no", but unobtrusively hinted at the huge sound source selection button with the inscription "AUX" on the front panel for the presence of an external signal input. By simple “googling” and careful abuse of the car’s interior, the coveted input was found in the form of four unused pin pins on the rear panel of the audio system, which looked like connectors on the motherboard for connecting the power, reset, LEDs and other buttons. Quite quickly, an inexpensive and simple stereo Bluetooth headset was purchased. A little tinkering with the manufacture of a cord connecting the headset's audio output to the audio input, during which the accuracy of the “factory” soldering of the headset and the wrapped cable for connecting additional USB connectors fell as a victim of the described debauchery (I went to make squirrelsmate audio connector), I tried this impromptu miracle of wireless technology.

Surprisingly, it worked well and I finally heard the long-awaited “beeps” from the “speakers” of the carmelodies. But the joy did not last long. The headset, being essentially wireless headphones in girlhood, required charging its own batteries or some other organization of its power supply, and here "the pig lay". The creation of a charger operating on a vehicle’s “on-board” power supply did not constitute any particular problems (at least for me, because a much more knowledgeable person was involved in this). The problem lay in the fact that when this power was turned on, in the headset (or maybe in the whole bunch of headset-cord-audio system-car) there were noises that killed the sound quality on the spot even from my far from audiophile point of view. Improvement of all this bacchanalia by the introduction of “galvanic isolation” (whatever that means), various filters and experiments to increase the noise immunity of the cable, much improved sound quality, but the noise still remained. At the same time, their character from time to time was very distinctly unknown to me by the “threads” either with the operation of the engine, or even with the operation of the dampers of the climate control system, which, when the ignition key is turned, are set by electric drives to a certain position. It became quite obvious that the headset normally didn’t want to work without significant modifications and a complete replacement that was brewing by that time (so what exactly - I didn’t want to think about it). In other words, Plug and Play did not work, alas. On top of that, another far more significant drawback of grief was revealed. In the course of a thought experiment, it turned out that when listening to music even while driving, it would sometimes be nice to switch tracks (who would have thought!). This could be done exclusively previously taking out a smartphone from a pocket. As a result, neither acceptable sound quality nor the notorious usability, but instead loomed on the horizon the prospect of complex enough for such a trivial task proceedings with the electrical part of the headset, car audio system, and maybe the car itself. The idea was cracking at the seams and asked for garbage.

Anatomy. Or how I got to the docking stations

Distracted from the next unsuccessful search on the Internet for a solution to these "arch-complicated" problems, I noticed a smartphone standing on my desk next to my computer (suddenly). It was the iPhone of the first and only then generation, bought, by the way, practically “from under the floor” (it’s even funny to remember, but in those troubled times “it wasn’t so easy to take and buy an iPhone”) although this is a completely different story. The main thing is that a fairly convenient docking station was attached to it absolutely free (unfortunately, Apple eliminated this corrupt practice in subsequent generations). It was in it that he stood on the table, and actually I turned my attention to it. The fact is that in addition to two 30-pin connectors (“dads” for connecting the smartphone itself and “mother” for the USB cable), there was also 3 5 mm TRS-connector (in the world of "mini-jack") with an unambiguous inscription "Line out". Having removed the headset from the car in order to use its cord to remake it into a docking station, as a result of which the old headphones became the next victim of debauchery due to the presence of the necessary connector, I put on the inside of the car a new design consisting of a smartphone, a docking station and an audio cable connected to the audio system. Anticipating another epic fail, I still decided to try a very tempting feature - combining the connection so far vaguely presented to me by a smartphone to the car's audio system and charging it at the same time. For this purpose, I took a USB cable with me into the car and a car charger that was purchased “on occasion” lying around idle. Having removed the headset from the car in order to use its cord to remake it into a docking station, as a result of which the old headphones became the next victim of debauchery due to the presence of the necessary connector, I put on the inside of the car a new design consisting of a smartphone, a docking station and an audio cable connected to the audio system. Anticipating another epic fail, I still decided to try a very tempting feature - combining the connection so far vaguely presented to me by a smartphone to the car's audio system and charging it at the same time. For this purpose, I took a USB cable with me into the car and a car charger that was purchased “on occasion” lying around idle. Having removed the headset from the car in order to use its cord to remake it into a docking station, as a result of which the old headphones became the next victim of debauchery due to the presence of the necessary connector, I put on the inside of the car a new design consisting of a smartphone, a docking station and an audio cable connected to the audio system. Anticipating another epic fail, I still decided to try a very tempting feature - combining the connection so far vaguely presented to me by a smartphone to the car's audio system and charging it at the same time. For this purpose, I took a USB cable with me into the car and a car charger that was purchased “on occasion” lying around idle. consisting of a smartphone, a docking station and an audio cable connected to the audio system. Anticipating another epic fail, I still decided to try a very tempting feature - combining the connection so far vaguely presented to me by a smartphone to the car's audio system and charging it at the same time. For this purpose, I took a USB cable with me into the car and a car charger that was purchased “on occasion” lying around idle. consisting of a smartphone, a docking station and an audio cable connected to the audio system. Anticipating another epic fail, I still decided to try a very tempting feature - combining the connection so far vaguely presented to me by a smartphone to the car's audio system and charging it at the same time. For this purpose, I took a USB cable with me into the car and a car charger that was purchased “on occasion” lying around idle.

Not only did the sound quality turn out to be at a very decent level (in principle, at the maximum available for the audio system), moreover, it did not deteriorate at all when charging was turned on (there were no “compatibility” problems), and most importantly, as a result, I was born "Crazy" thought - without thinking up anything else, leave everything as it is with this desktop and not yet inspiring docking station.

For this purpose, without delaying the matter, I decided to conduct “flight” tests of the docking station and check whether it is able to keep the smartphone on the go. I put it with my smartphone on the only suitable horizontal surface in the cabin - the “shelf” on the top of the dashboard near the windshield, and, holding my “new solution” with my hand, went to look for bumps and potholes. For some well-known reasons, I didn’t have to search for a long time, and soon I was surprised to find that the docking station not only holds the smartphone perfectly even at “exorbitant angles of attack”, at which you start to worry more about the car rather than the ability to listen to music, but also with its help smartphone turned into a carriageuniversal head unit for the car audio system, which is a very convenient player, as well as a kind of small likeness of CarPC. Well, in any case, it was possible, for example, to open some kind of map on the Web and get directions, even if using only the Sun, stars, traffic lights and other landmarks (due to the lack of GPS on the “breakthrough Internet communicator”, you can use your smartphone as a full I didn’t have a replacement for a car navigator at that time). At the same time, thanks to the extremely successful design of the docking station, putting and removing a smartphone from it did not cause any trouble. For this, Joni , accept my sincere appreciation. Of course, if you read Habr (not, well, what if!).

The “secret” of such a combination of ease of use and the ability to hold the smartphone securely that struck me was the extremely simple and, in my opinion, elegant technical solution - the geometry of the recess in the “monolithic” case of the docking station into which the device is inserted, with minimal gaps that prevent large backlash, repeats the geometry of its body, while holding it and acting as guides for the exact docking of connectors.

Believing in the approaching torment finale, I quickly mounted it all in the car interior cleanly, gently screwing the dock to the plastic of the dashboard, laying the cables in its internal space, and also connecting the fuse box to the glove box and securing the charger there, and began to rejoice.

I was happy, I must say, this time long enough. But time passed, the trees became small, and cellular networks improved. At some point, having decided that to continue with the completely outdated EDGE and without GPS was somehow uncomfortable, and “for the premium that I legally owed” I upgraded my iPhone to the version that was fresh at that time - the 4th version (“The latest model! ") And continued to rejoice, anticipating that now I will also have a car navigator, but the number of devices will not increase (well, I don’t like extra devices) Now I had to rejoice exactly until the moment when I tried to install my new “head unit” on the old dock with the usual movement of my hand. Despite the fact that it was designed for a completely different device in form, a more "square" newcomer nevertheless got into it. It’s just that the old “magic” disappeared - the new smartphone dangled openly in the obviously deep recess of the docking station and dangerously twisted, trying to fall out of it, simultaneously breaking the connector, which, moreover, it was difficult to get into during installation and only which he, apparently, was holding on. Not particularly upset even by the fact that there would be no freebie in the form of the corresponding docking station attached to the new smartphone, I was going to purchase it, naively believing that this annoying nuisance would be eliminated, so to speak, low blood pressure by quick and easy replacement. Only a trifle stopped me - at that time these newest docking stations did not exist in nature, and on the open spaces that were visible to me this existence was not supposed even in the near future. Apple continued to surprise and this time unpleasantly. It was necessary to come up with something.

Having examined the options for affordable universal car holders, I noted a number of drawbacks in them that cast doubt on the appropriateness of their use in this particular case of mine. For example, they contained the necessary 30-pin connector, but there was not even a hint of any semblance of a linear output. He would have to organize it himself, and given the presence of only a cigarette lighter connector on the end of the cord for such holders, this threatened to turn into the manufacture of a new cable with concomitant abuse of the structure of the holder, in which a 30-pin connector with the coveted linear output on which then from his contacts (I don’t remember exactly for years ago, but then I didn’t even seem to find his pinout). Constructions from just a mechanical holder and a separate cable, for myself, I considered completely heresy in terms of ease of use (I was haunted by a successful experience with the docking station, in comparison with which using all these latches and grips looked complicated and dull). In addition, the main drawback for me and my car of almost all such holders was their method of attachment - on a suction cup to a glass or other smooth surface (I just could not find a single place in the cabin where I could fix it, without closing myself review or without losing the opportunity to interact with a smartphone without complex gymnastic exercises). I wanted compared to which the use of all these latches and grips looked difficult and dull). In addition, the main drawback for me and my car of almost all such holders was their method of attachment - on a suction cup to a glass or other smooth surface (I just could not find a single place in the cabin where I could fix it, without closing myself review or without losing the opportunity to interact with a smartphone without complex gymnastic exercises). I wanted compared to which the use of all these latches and grips looked difficult and dull). In addition, the main drawback for me and my car of almost all such holders was their method of attachment - on a suction cup to a glass or other smooth surface (I just could not find a single place in the cabin where I could fix it, without closing myself review or without losing the opportunity to interact with a smartphone without complex gymnastic exercises). I wanted at the same time, without closing your review or without losing the opportunity to interact with your smartphone without complex gymnastic exercises). I wanted at the same time, without closing your review or without losing the opportunity to interact with your smartphone without complex gymnastic exercises). I wantedstrawberry amenities and I decided to make a do-it-yourself car holder, devoid of all these shortcomings and satisfying me 100%.

Actually action

Having disassembled the existing docking station and taking out a small board with a connector soldered on it and getting rid of the cargo present there, I decided that it would be easiest to use this small board in some base of my future holder, and to conduct cables covertly from existing connectors through the structure bracket, which did not exist even in my fantasies.

Leaving for a while heavy thoughts on the methods of manufacturing the bracket and the base of the holder, I began to search for the place of its installation in the passenger compartment. The place where the left vent of the ventilation system was located on the central “console” of the dashboard — to the right of the steering wheel, not too high and not too low, was right at hand.

At first, I even intended to somehow use this deflector to mount the holder, including by passing through the holes of the elements of the future bracket with wires and subsequently reliably fixing them to the power elements of the body already in the interior of the dashboard (then the whole structure seemed quite heavy to me and with a large shoulder), but refused this venture, because I did not want to spoil too much the original plastic interior elements. Under the deflector was a removable button block with a corresponding hole, which fit even better than the deflector holes. It turned out that despite the mirror symmetry of all this "non-Euclidean" geometry of the plastic lining of the central "console" (the photo above shows a gray element, including a horizontal shelf, ventilation deflectors, buttons and the frame of the car radio), the button block could be painlessly swapped with a strange dummy. By the way, the purpose of this thing was a mystery to me for a long time (however, as I found out in the process of searching for illustrations for this post, it was not only for meriddle ). Just pulling it out of my socket, I realized that it was a kind of coin box (so European designers decided to add functionality to an elementary stub), and not some thermometer, sensor or microphone of the Handsfree system for more expensive trim levels, as I thought earlier. I decided to sacrifice this piece of plastic, useless to me.

Having decided on the future location of the smartphone, I thought: why do I need to build some kind of complex bracket, especially since it would be more convenient to place the smartphone as close to the surface of the dashboard as possible? Wouldn’t it be easier to somehow fix the dock card directly to this coin box, turning it into the only, and most importantly, ready-made element for attaching the holder to the dashboard? It only remained to figure out how to combine all this into a monolithic case, which, if possible, would also possess the "magic" of the docking station, that is, it would have a recess around the connector, repeating the shape of a smartphone.

Epoxy resin! Collect all that I had, make a mold that defines the outer surface of the holder and fill it all with “epoxy” (to hell! Really, how much can you do?)! It would have turned out to be a monolithic and durable "plastic" design, which is easy to process and bring to a completely acceptable appearance. My inexplicable glee was overshadowed only by the prospect of the complex manufacture of this very form. It would be necessary to make a kind of “trough”, on the one hand limited by the overlay of the central “console” of the dashboard (otherwise it would have to make an ugly and complicated transition from its surface to the volume of the holder due to the fact that it turned out wider than coin boxes) on the other hand, into which another form would be immersed, which is a kind of "cast" of the smartphone.

"Epoxy", "troughs", "casts" - it was like nonsense. From all this geometry (which, by the way, is not only difficult to describe like this, “on the fingers”, but, I believe that the pictures from the video here would not help much either), the brain was boiling and I no longer wanted any music. How, for example, to make this "smartphone cast"? Do not heat the smartphone in epoxy. The idea was not worth it. It was necessary to stick around the smartphone with something like plasticine and fill the resulting form with something like gypsum. Thoughts about the “epoxy” and plasticine strangely mixed in my sick imagination and turned into ... “cold welding”, or rather, “plastic epoxy composition Epoxylin”. As it turned out later, a thing very popular in the hand of fornication delia.

Easy to use! “After curing, you can polish, drill, paint”! This is what I need! Always dreamed of polishing, drilling and painting after curing! A second wave of jubilation came over me. I vividly imagined how I would break the front part of the coin box, turning it from a kind of rectangular glass into a rectangular like a tube, cut through the grooves in its side walls in order to insert and fix the dock card, connect the cables and plug the smartphone into the connector I wipe it all into a single array, which then will only have to give the finished form in places and voila.

Once again the glee was interrupted (this is no longer funny). This time I faced the problem of how to painlessly stick my smartphone around with this very “tenacious” epoxy compound (in the end, it is designed to glue all types of metal, plastic and glass, that is, to stick my smartphone to anything). I needed to somehow protect him. For this purpose, I decided to wrap the smartphone in a plastic bag, and then coat with some kind of release agent. The idea failed due to the fact that, firstly, polyethylene created a large number of quite large folds on the surface of the smartphone (they would certainly have printed on the form), and secondly, it simply broke when trying to "fit" the smartphone packed in this way onto the connector. I needed something that could stretch a lot, precisely fitting the device and connector of the dock board, and at the same time have sufficient tensile strength. I did not have to think for a long time.

Having collected everything necessary for the manufacture of my original car dash-dock holder, I had finally and by that time made myself somewhat aloof from what I was actually doing, pulled a condom on my smartphone with a “flick of the wrist” and stuck it in the connector on the board . To my own surprise, I didn’t even say something like “Hehe”, and noted that I even came in handy for the described operation ... “pimple” at the end of a rubber-technical product (dear Habr, I must admit that when writing this post I I even honestly tried to find more on the Internet than the technical term for this part of the device used, but, alas, I did not find it). This bulge has turned into a recess embedded in the smartphone’s connector, reduced the tension in this part of the pairing of the smartphone and the dock board (in these terms it is really not easy to describe) and at the same time completely eliminated even the slightest possibility of wrinkles that would ruin the shape. “It sits like a glove,” I concluded, and driving a few air bubbles out of the place where the smartphone and the dock would come in contact, I started stuffing with Epoxylin, a pre-prepared and processed plastic coin box with a board. Having finished with this fastener, I inserted it into the cover of the central “console” of the dashboard previously removed from the car and, this time giggling idioticly, smeared the grease from the condom package with the surface of this cover around the proposed dock so that later on the need to be able to take it out painlessly. Then,

“After curing”, I hastened to disassemble the whole structure, easily pulling out my smartphone and finding a perfectly smooth inner surface of the recess with an unscathed connector at the bottom that faithfully repeated the shape of the smartphone (even a small dent in its lower part was repeated - a consequence of the fall) and perfectly fixed it . The recess itself was located in a formless block of very strong “plastic”, on the other end of which there was an untouched case of a former coin plug, which, with a characteristic click, was securely fixed in the aforementioned element of the car dashboard, practically docking the dock with a dash to it - station (the body was fixed even better than before, apparently due to the fact that it was slightly wedged as a result of tight packing with this “plastic epoxy compound” and that I’m trying, just in case, to improve “adhesion” by pre-drilling holes in its walls). Honestly, I was pleased with the result (up to this point, I thought that the docking station would most likely be buried in the bowels of epoxy and that would be all). The matter remained small.

This is the end!

This "small" I hastened to do. Having wiped the smartphone and everything else from the ubiquitous grease, I returned everything seized earlier in the car and turned it on. Surprisingly, everything worked perfectly (Epoksilin turned out to be a really good dielectric). Having disconnected the almost ready-made holder, I began to give it a "presentation". I decided not to bother with the design and rip it off from Apple (come on, Johnny), trying to repeat the forms of the original docking station as much as possible, especially since it was very convenient for such a repetition (essentially a parallelepiped with one “beveled” face and rounded vertical edges). Sawing, as well as processing with sandpaper and needle files, this material was very simple. The surface at the same time turned out to be quite smooth, and after “polishing” with a simple cloth it even acquired a shine. The only thing I did not dare to do was try to color it normally. I decided that applying any enamel to the surface would not work out with enough quality and the smartphone would “wipe” it during operation, and the influx of paint could completely unacceptably reduce the already small gap between the surfaces. Anyway, I frankly faked it - I took an ordinary permanent marker of black color and “painted” the surface in this way. It turned out, to put it mildly, “not very”, since color inhomogeneities were visible near (no matter how hard I tried, but the material absorbed the dye composition and the felt-tip effect was obtained on paper, besides, the small filler granules present in the same tone didn’t "Epoxylin"). The smallest surface defects were also revealed, which I did not notice before painting and which, I believe, could be removed with normal staining. Nevertheless, I did not begin to redo anything, especially since from a normal distance the craft did not look so terrible and did not even catch my eye. From a single photograph taken, you can evaluate the result of a whole working day. to put it mildly, “not very,” since color inhomogeneities were visible near (no matter how hard I tried, but the material absorbed the dye composition and the felt-tip effect was obtained on paper, besides, the small granules of the filler present in Epoxilin did not want to be painted in the same tone "). The smallest surface defects were also revealed, which I did not notice before painting and which, I believe, could be removed with normal staining. Nevertheless, I did not begin to redo anything, especially since from a normal distance the craft did not look so terrible and did not even catch my eye. From a single photograph taken, you can evaluate the result of a whole working day. to put it mildly, “not very,” since color inhomogeneities were visible near (no matter how hard I tried, but the material absorbed the dye composition and the felt-tip effect was obtained on paper, besides, the small granules of the filler present in Epoxilin did not want to be painted in the same tone "). The smallest surface defects were also revealed, which I did not notice before painting and which, I believe, could be removed with normal staining. Nevertheless, I did not begin to redo anything, especially since from a normal distance the craft did not look so terrible and did not even catch my eye. From a single photograph taken, you can evaluate the result of a whole working day. besides, the small granules of the filler present in Epoxilin did not want to be stained in the same tone). The smallest surface defects were also revealed, which I did not notice before painting and which, I believe, could be removed with normal staining. Nevertheless, I did not begin to redo anything, especially since from a normal distance the craft did not look so terrible and did not even catch my eye. From a single photograph taken, you can evaluate the result of a whole working day. besides, the small granules of the filler present in Epoxilin did not want to be stained in the same tone). The smallest surface defects were also revealed, which I did not notice before painting and which, I believe, could be removed with normal staining. Nevertheless, I did not begin to redo anything, especially since from a normal distance the craft did not look so terrible and did not even catch my eye. From a single photograph taken, you can evaluate the result of a whole working day. that from a normal distance, the craft didn’t look so terrible and didn’t even catch the eye. From a single photograph taken, you can evaluate the result of a whole working day. that from a normal distance, the craft didn’t look so terrible and didn’t even catch the eye. From a single photograph taken, you can evaluate the result of a whole working day.

As for the convenience and functionality, the device has served me without any complaints for several years and, being in good health, together with the car and smartphone successfully transferred to the current owner.

In conclusion, I would like to say that I understand perfectly well that most likely I then invented the next “bicycle” and much could have been done differently and better, including regarding the writing of this post. I think spring comments will show where I was right or wrong (and who I am after all that I did). One way or another, I pass on my “revelations” to the court of the respected Khabrasociety and ask only that they not judge me severely.

In the end, I was young and I needed a car holder for a smartphone.