We fix the USB cord on the knee. Homemade flash drive For a variety of devices
Everyone knows that any electronic device can be connected to a computer using a standard USB cable. Thus, using a laptop or personal computer, you can connect various devices to each other, such as printers, cameras, smartphones and data storage devices (flash drives and external hard drives).
What is OTG?
Is there a way to do without a computer? Easily, a lot of adapters under the general name OTG cable have appeared on the market for a long time. Their cost varies from a few dollars to a dozen or even two. However, their difference from simple data cables is so insignificant that you can easily make an OTG cable with your own hands. For example, from the remains of old and adapters.
So, first we need to decide what we need an OTG cable for. You may need to power another device from the battery when there is no power nearby, for example, when traveling or hiking, but this option is not the most efficient. We need to immediately decide whether we will constantly connect two specific devices to each other or is it better to make a universal OTG cable with our own hands to use any USB devices, like a store-bought one. It is also better to immediately check whether your device is capable of supporting such connections.
Tools and Safety
When working with cables you will need:
knife for stripping insulation;
wire cutters or side cutters (remember the saying: "measure 7 times - cut 1"), excess solder on the cable will degrade the quality of communication between devices and increase the resistance in general, which will affect data loss or inability to charge due to conductor resistance;
soldering iron, solder and flux; at the end of the article we will consider how you can do without this device.
When working with a soldering iron, remember the safety measures. This device is dangerous due to its high temperature not only during operation, but also for several minutes after turning it off. Protect the table top from molten tin or rosin. Protect exposed skin from touching the heated parts of the soldering iron.
What is what?
To begin with, it is worth sorting out which contacts in plugs and sockets are needed for what, since in mini- and micro-versions there is 1 pin more than in universal serial bus connectors. So, the first pin is standardly marked with red insulation inside the wire, designed to supply voltage. The second and third pins, marked with white and green insulation, are for data transmission. The fourth black pin is zero or ground, working in tandem with the first supply wire. In mini- and micro-USB, such functions are assigned to the fifth, last pin, and the fourth is a marking or identifier. It is designed to provide connection information to the device and is not connected anywhere in the data cables.
The simplest option
First of all, consider the option of connecting two specific devices together, for example, a tablet computer and a camera. Since they both have 5-pin sockets, be it micro or mini USB, you just need to carefully solder the corresponding wires together. 2 unnecessary data cables with suitable plugs will do. You need to cut them and strip the wires from insulation, and then connect them according to color differentiation, that is, black to black, yellow to yellow, and so on. Each connection must be isolated from the others with hot glue or at least electrical tape. When connecting such a cable to devices, a dialog menu will appear on the screens, where you will need to select which of the devices will be the main one in this mini-network. It is possible to forcibly designate the main and secondary device in the cable itself. To do this, in the plug of the main device, you need to connect the 4th and 5th contacts, and in the other plug, the 4th contact simply does not connect to any. Thus, the device will automatically determine itself as the main one in the connection, since the marker contact will show the presence of the connection, while on the second device it will be “empty”.
For a variety of devices
Consider the option of how to make a universal OTG cable with your own hands. In addition to a micro or mini USB plug, depending on the device, we need a USB connector. You can take it from old motherboards, cut it off from a USB extension cable, or disassemble a USB splitter (the so-called USB hub). The latter option is preferable, as it will allow you to connect several peripherals to the main device at once, like to a computer. The connection sequence is the same as above, the main device is forcibly indicated on the device plug in the same way, connecting the 4th and 5th pins. The figures clearly show the connection diagram of the pins in the connectors and plugs.
With power connection
Some devices are characterized by increased power consumption, which leads to a rapid discharge of the battery of the main gadget, whether it be a smartphone or tablet. In this case, you can improve the OTG cable with your own hands by adding a power cable with a USB plug for the network adapter. To do this, you can use the remnants of the data cable from which the micro or mini USB plug was previously cut. The connection is made on two current-carrying contacts, black and red, ignoring the data wires. It must be remembered that over long distances, the resistance of the wire, reinforced by solder joints, will reduce voltage and current, so using long cable lengths will most likely not allow you to achieve a stable connection between devices. Use approximately 20-30 cm of cable for each plug and socket to avoid breaks and interruptions in the connection.
Finally, I would like to mention how to assemble an OTG cable with your own hands without a soldering iron. The assembly principle is the same as described above, however, the wire connections are made in several other ways. We list two of them here:
Solder paste contains solder powder and flux and does not require the use of a soldering iron. Such a paste is applied to the parts to be joined and heated with an ordinary lighter.
There are compounds without the use of high temperatures at all. The so-called adhesive locks are connectors for low-current systems with a special contact that cuts into the wires using a clamping device, for example, pliers.
Whatever you decide to do with your own hands, remember that cutting cables is not a warranty case and such cables cannot be replaced.
In connection with studying abroad, I had to transfer completely to a laptop. I took my SS Kana gaming mouse with me. Of course, a wired mouse is not designed for frequent movements, over time, the cord began to break at the very base, more and more contact began to disappear. During the last three months I tried to keep the mouse working, even stopped taking it to classes, but the day of the P came, and the contact disappeared completely; no manipulations have yielded results.My Greed for an expensive mouse and Laziness to go buy a new one rallied against me and forced me to repair the contact. I’ll make a reservation right away that I’m writing this article after the fact, I didn’t write anything step by step, but I’ll show you how this is done with an example. The quality of the photos leaves much to be desired, but you can capture the essence.
Equipment
Knife. All. I don't have duct tape or any tools handy.Ordinary kitchen knife. Sharp enough to cut insulation without problems.
The original version included soldering with a state-owned soldering iron, obtained at the university, however, due to some circumstances, which I will describe below, I had to redo everything.
original version
As I said, the cable broke at the very base. In order to get at least a little space, I cut the plug with a knife and stripped all four wires. I twisted the cable braid and turned it to the side, after which I went to the university for a soldering iron. They gave me an old soldering iron, a spool of millimetric solder and a jar of flux. I have soldering experience, so it turned out fine. The only drawback is that since all four wires are very short, located at the same level, and I didn’t have insulation, I got a kind of “rose” of wires sticking out in different directions. However, the test run turned out to be successful - the mouse came to life, and I, proud of myself, returned to the hostel.But there I was disappointed. Without going into details, I most likely shorted the black and red wires and the laptop blocked the USB socket. Therefore, no matter what I did next, the mouse did not react.
Trying to figure it out, I began to sin on the braid (that it shortens the wires), even cut it off, it didn’t help anything. In the end, I completely cut off the fork and decided to do everything in a new way. It would be worth restarting the computer and trying again, most likely, the mouse would have worked. Who knows...
The connection is very small, I don’t have a normal camera. It's just that all four wires stick out in a bundle from the plug and a corresponding wire is soldered to each. The braid is cut off, because I thought she was shorting the wires. Doesn't matter.
Connecting cables
By evening, I took the mouse out of the drawer and set to work. First of all, I took a new plug from an unnecessary mini-USB cable.
USB cords are not much different from each other - four wires (black and red for power, white and green for information) and a braid. So any USB cable will do.
When fixing, I used the method described. In short - multi-core cables are connected by a "ladder". Thus, the wires do not touch each other and the connection is thinner.
Using the example of the remaining piece of wire, I will show how this is done. First, carefully cut off the top insulation to a length of about four to five centimeters. 
We unravel the braid and take it to the side. 
Then we expose 4 wires with a “ladder” - red is only the very tip to twist; white is slightly longer, with the expectation that it does not touch the red; then green. We clean the black furthest. We expose the other cable in the same way, only mirror - only the tip is black, then green, white and red at the very base. Thus, we exclude the short circuit of the wires with each other. 
It remains only to connect the two cables together. We connect each wire with a twist. I hope you don't mix up the colors. After twisting, it is better to cut off excess wires to avoid unnecessary contacts. 
In my version, I also covered the whole thing with a piece of top insulation to avoid touching the braid. In the future, I plan to either get electrical tape somewhere, or ask the girls for clear varnish for insulation. 
After processing with electrical tape, of course, it will all take on a divine form, but for now the braid will hang in such a strange way. The connection is working, there are no extra contacts. Mouse works like new!
However
The mouse immediately stopped working. Already completely desperate, I noticed a system message about violations of the USB inputs. As I said, the original version shorted the contacts and the laptop cut off the USB inputs. After a reboot, the mouse worked again. Of course, the connection is short-lived, without electrical tape in any way, but the mouse works.Thank you for your attention. I hope this article has helped you.
P.S. this is my first article on Habré. Thanks for the invite!
Content:In working with computer equipment, some non-standard additional devices are often required. For example, with a local network device, you may need a cable of various lengths equipped with USB connectors. However, standard factory-made products do not always meet the requirements. In such cases, you have to make a USB extension cable with your own hands.
The principle of operation and scope of USB extension cables
To make a normal working extension cord, you need to know its properties and principle of operation well. First of all, its length depends on this. Everyone knows that with a regular cable it is possible to connect remote devices at a distance of 3-5 meters. These cables are considered passive extension cables, and in many cases, this distance is not enough to ensure normal operation in a home or office. It is not always possible to locate a printer, scanner, and other peripherals near a computer.
This problem is successfully solved by an active USB extension cable, which is fundamentally different from a conventional cable. Its useful qualities are manifested by active amplifiers built into each end and powered from USB connectors within 5 volts. Due to this, the useful signal is amplified many times, which makes it possible to connect devices remote from the computer at a distance of 50 meters or more.
In the process of signal transmission, its inevitable weakening occurs. In this regard, for long distances (over 5 meters), only the USB 1.1 protocol is used. At a distance of up to 30 meters, the use of a faster USB 2.0 protocol is required. Of great importance is the cable connecting the devices to each other. It must be of high quality, guaranteeing the same high connection speed.
The work of the extension cable is carried out independently without any drivers and does not affect the state of the computer in any way. It is enough just to insert the USB plugs located at the ends of the wire into the corresponding connectors of the equipment to be connected.
Extension manufacturing process
It should immediately be noted that self-production of a USB extension cable requires special knowledge, practical skills in working with a soldering iron and other power tools. Otherwise, it is recommended to purchase a finished product of the desired length, although it will be more expensive than a homemade one. However, many still try to make a USB extension cable on their own.
First of all, you need to stock up on a standard USB cable of short length. If possible, it should have a ferrite core capable of damping high-frequency interference and indicating the high quality of the cable. You can ask for such a segment or buy it inexpensively from people involved in cable lines. You can also ask them for the required amount of UTP computer cable, preferably one of the high categories, for example, 5e, 6 or 6e. The speed of the equipment at the opposite end will depend on this.
From the tool you will need wire cutters or scissors to cut the cable. performed with a special tool, but in its absence, you can do with a simple knife. For connections, you will need a soldering iron, solder and rosin, since twisting of wires is not allowed due to their high resistance. The joints are insulated with heat shrink tubing. You can use electrical tape instead.
Work begins with cutting the cables into segments of the required length and stripping the ends. The insulation from all conductors is removed by about 3-5 mm. USB cable contains 4 conductors, UTP cable - 8. One pair of UTP cable includes two wires - colored and motley. Instead of motley, there may be a white wire. Each such pair is soldered to a separate USB cable wiring in accordance with the corresponding colors. According to the same scheme, a do-it-yourself USB extension cable is made with additional power, known as an active extension cable.
Upon completion of soldering, you need to check that there are no broken places left. After that, the heat shrink tubes are moved to the soldering points and heated with a building hair dryer until they are completely attached to the connected conductors. After all the heat shrinks on the conductors have cooled, they are assembled together into a single bundle, on top of which a common heat shrink tube is installed in the same way. Before connecting the equipment for the first time, it is advisable to check the contacts with a tester. If the test showed the norm, then a home-made extension cord can be used for work.
USB twisted pair extension cable
Twisted pair extension cords are mainly used to connect the Internet via a 3G modem. These devices are used in dachas and country houses, in the absence of the possibility of conventional cable Internet. Often situations arise when reliable reception of a 3G signal is possible only from a certain place, to which a separate cable is required. Often, a usb extension cable of the right size is not available for sale, so the only way out is to make it yourself.
For this purpose, you will need the right amount of twisted pair shielded with foil, two USB connectors AM and AF, that is, "male" and "female", 16 mm heat shrink tubing, and electrical tape. Of the tools you will need a knife, side cutters, a soldering iron, solder and flux.
The manufacturing process begins with pairing and aligning the ends of the twisted pair with side cutters. After that, using a knife, you need to remove the upper sheath of the cable along with the foil at a distance of 1 cm from each end. This operation must be done very carefully so as not to cut the wires located under the sheath. Brown-white and brown wires are cut flush with the sheath, as they will not be used later. From the remaining conductors, 3 mm of the insulating layer must be removed. The wires are connected as follows: green to orange and green-white to orange-white. The joints are carefully soldered.
The heat shrink tube is pre-cut into pieces of 4 cm each and put on a twisted pair. This will allow you not to solder the connector in the future. The correctness of the desoldering should be checked very carefully, as accidental confusion can lead to failure of the USB device.
After checking, you must turn on the modem in test mode. If the computer does not recognize the device or shows incorrect operation, you need to try another connector. The absence of a positive result indicates too much current consumption. Since the wires are very thin, the modem simply does not have enough voltage. It may be necessary to shorten the wire until the device starts working or increase the size of the wires. If the whole system is working normally, it remains to put heat-shrink tubes on the connectors and, after heating, check the quality of the insulation.
How to make a DIY USB extension cable?
The conclusion is simple. If you don't have engineering talent, soldering experience, consumables, or USB cable pinout, it's much easier to buy an active extension cable that can be easily used as a 5m USB extender, 10m USB extender, 15m USB extender, and so on. up to 50 meters! It is guaranteed to work with any device. If you have the listed talents, but absolutely little money, then you can make a USB extension cable with your own hands. It's not difficult at all.
Of course you can! There are absolutely no difficulties in this. All you need is:
Standard short USB cable, preferably with a ferrite core. The core serves to dampen high-frequency interference and is an indirect evidence of the good quality of the cable. You can buy, but it is better to beg from any IT specialist at work, they usually have a bunch of these cables.
- computer UTP cable of the required length (as short as possible in place). At the same time, the higher the category of the cable (5e, 6, 6e), the faster the speed of the device at the far end, or you can take a longer cable. The recommendation is the same, IT specialists have kilometers of this stuff.
A simple set of tools for the job. Nippers, although you can use ordinary scissors. A cable stripping tool, but as a rule, everyone uses a knife. Soldering iron, solder, rosin. Without this, nowhere - twisted wires have much greater resistance. And the last - heat shrinkage to give the design a professional look. If you don’t give a damn about beauty, feel free to replace it with ordinary electrical tape (adhesive tape is usually a thin layer of polyethylene with glue. It won’t work.)
So, when everything is ready, feel free to cut the free cable in half with scissors borrowed for 5 minutes from the accounting department. Then, with a knife taken from the public kitchen, carefully (not to make good contact, but not to cut yourself) remove the insulation by 3-5 mm. from all conductors. 
In the USB cable we have 4 conductors, and in the UTP cable there are 8. Let's guess how many wires from the UTP cable need to be soldered to one wire in the USB cable? For those who did not go to school, we inform you that it is better for you to quit this idea altogether. And the rest carefully solder the conductors together, without confusing colors. Solder each pair of colored and variegated (coloured white) wires to one conductor of the USB cable at both ends of the UTP wire. If you managed to find heat shrinks of two diameters - thick and thin, then do not forget to put them on the entire cable and on each conductor of the USB cable BEFORE soldering. Then it will be somewhat inconvenient to do so. If you do not know what heat shrink is and where to get it, limit yourself to electrical tape.
When the soldering is successfully completed, there are no breaks and unsoldered ends, move the heat shrinks to the place of the solder and heat them with an industrial hair dryer, one by one until they completely shrink and fit to the place of soldering. Who does not know what an industrial hair dryer looks like, always uses an ordinary lighter. Allow each heat shrink to cool, then gather everything into a neat bundle and do the same procedure with a large heat shrink, over the entire soldering point.
There is nothing difficult. However, before the first connection of some expensive device, it would be nice to ring the contacts with a tester, again asked from good IT people. They generally always have a lot of things that you can ask for. Golden people!
Attention! You perform all work at your own peril and risk. We are not responsible for your wasted time, your damaged nerves, cut or burned limbs, disabled office equipment, etc. It is better to trust professionals and buy a finished product that will surely be more beautiful, more functional, more reliable and faster.
Hello my friends. Today we will not consider any schemes of certain designs, the topic for today is the so-called homemade flash drive. Some, of course, may not believe that this is possible at home, and they do it right, since it is quite difficult and it is almost impossible to do it at home without special equipment. But smart people have long come up with a memory card for mobile phones. In stores, you can easily find an adapter with which you can connect a memory card to a computer via a usb port. This adapter only costs $2.
The device works very simply - you just need to put the memory card in a certain place on the adapter, and the adapter itself is made in the form of a USB plug that only needs to be connected to the PC's USB port. For our homemade flash drive, you need to have just such an adapter with a memory card from a mobile phone and one more plug or an appropriate plastic case for USB.
Then we place the adapter in the plug casing and close the cover and see what we got.
Now it looks like a cut off USB plug, but no one will even suspect that there is a memory drive there! Now it's time for the schematics. There are 4 wires, we remove a small part of the insulation from the wires in advance and tin them. Next, we take a couple of brand new parts (it is better to take damaged ones, but so that they look like new ones) and share them with each other. There is no specific circuit here, solder whatever you want, the design should just look like a circuit, of course it will not work! You can use capacitors, resistors, polar and non-polar capacitors and a couple of transistors, as you know, some flash drives have a built-in LED indicator on the back, you can get a simulator of such an indicator so that our home-made flash drive looks believable and does not raise doubts.
To do this, an unpacking of the USB socket and plug is attached to the article, power is supplied through the side channels that needs to be connected to our wires, then assemble the simplest flasher circuit for one LED, in which case we have two more free wires to which we can attach a pre-made<блеф>memory storage diagram. So, let's summarize - we got a rather interesting design, when connected to the usb port of the computer, the LED will start blinking and it will give outsiders the feeling that a flash drive is connected, but they will be more surprised when the computer notifies that a memory drive is connected to it! Yes, everyone will begin to believe that you are a genius and ask for a diagram of such a simple miracle flash drive. Try to make the details connection scheme as confusing as possible, so that even the master does not suspect what the deception is. Well, that's all, you can see such interesting gizmos in further articles, goodbye friends - Arthur Kasyan (AKA).
