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 communicate with each other various devices 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? Quite simply, 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 yourself. For example, from the remains of old and adapters.
So, first we need to decide what we need an OTG cable for. Powering another device from the battery may be needed in the absence of power outlets nearby, for example, on trips or hiking trips, but this option is not the most efficient. We need to immediately decide whether we will connect two specific devices permanently to each other, or whether it is better to make a universal OTG cable with our own hands to use any USB devices, like a store one. It's also best to check right away if your device is capable of supporting such connections.
Tools and safety technology
When working with cables you will need:
insulation stripper;
nippers or side cutters (remember the saying: "measure 7 times - cut 1"), an extra solder on the cable will worsen the quality of communication between devices and increase the resistance in general, which will affect the loss of data or the impossibility of charging due to the resistance of the conductor;
soldering iron, solder and flux; at the end of the article we will look at how you can do without this device.
Remember the safety measures when working with a soldering iron. This device is dangerous due to its high temperature not only during operation, but also for several minutes after switching off. Protect the work surface of the table from the ingress of molten tin or rosin. Protect exposed skin from touching hot parts of the soldering iron.
What is what?
To begin with, it is worth making out which contacts in the plugs and sockets are for what, since in the mini and micro versions there is 1 pin more than in the connectors of the universal serial bus. So, the first pin is standardly marked with red insulation inside the wire, it is 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, paired 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 feed 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 to each other, for example tablet computer and a camera. Since both of them 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 matching plugs will do. You need to cut them and strip the wires from the insulation, and then connect them according to color differentiation, that is, black with black, yellow with yellow, and so on. Each connection must be isolated from the others with hot glue or at least electrical tape. When such a cable is connected to the 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. You can forcibly designate the main and secondary devices 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, simply do not connect the 4th contact to any one. Thus, the device will automatically determine itself as the master in the connection, since the marker contact will indicate the presence of a 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 the 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, since 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 forcedly 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.
Connected to power supply
Some devices are characterized by increased power consumption, which leads to a quick discharge of the battery of the main gadget, be it a smartphone or tablet. In this case, the do-it-yourself OTG cable can be improved by adding a power cable with a USB plug for 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 off. 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 with solder joints will reduce voltage and amperage, so using long cable runs will most likely not allow you to achieve a stable connection between devices. Use approximately 20-30 cm of cable for each plug and connector 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 slightly different ways. Here are two of them:
Solder paste contains powdered solder and flux and does not require a soldering iron. Such a paste is applied to the parts to be joined and heated with an ordinary lighter.
There are no connections at all high temperatures... The so-called adhesive tape 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 the cables is not a warranty case and such cables cannot be replaced.
Almost any manipulator is connected to a computer using a special USB cable, thereby turning into an information input device. This allows you to create an entire ecosystem of various devices, but what if you need to trivially connect a keyboard to a tablet or smartphone?
For this, there are otg cables, which in fact are simply cleverly named adapters between micro-usb and usb. Allowing you to connect mice to the same smartphones and use them freely with the help of additional software and drivers, without restrictions. Such a cable for connecting external manipulators costs from a couple of dollars to a dozen, depending on the manufacturer, the quality and number of devices connected at a time. And the main question of our man in the street: how to make such a device yourself, so as not to waste money? Fortunately, for this, an old charger and an unnecessary connector, as well as pliers and electrical tape, are enough.
In fact, such a device does not have any complex microcircuits or adapters, all controller configuration occurs due to the internal software of the tablet or phone, therefore it is just a cable with input and output that can be made in 10 minutes. And yet, how to make an otg cable with your own hands if you only have an old smartphone charger? Why do you need to connect external manipulators to mobile devices at all, and how to deal with differences in the current strength of devices? And what do you need to know about OTG before using it?
Application methods
Before picking up a soldering iron, it is worth understanding why you need such a cable at all? After all, there are a lot of keyboards for the same tablet, specially created and designed for ease of use, not to mention gamepads and mice. Is this really a common adapter for those who cannot afford such a "zoo" of information input devices? In fact, it is much more universal device, because micro-usb is used in the same powerbank, and the phone or tablet itself with enough powerful battery becomes a separate charging device. So, you find yourself in a situation where the laptop is almost discharged, but the phone has 100 percent, here otg support will come in handy.
Yes, a 2-4 thousand mAh battery will not last long. But if we are talking about urgently responding to a letter or sending a project to the authorities, the time is already ticking by seconds. In addition, the opposite situation is also possible, and with the help of such adapters, you can always give part of the charge to a friend with a discharged smartphone. But before starting to celebrate cutting off the nearest old charger, make sure you have a soldering iron and a tin. In fact, the same OTG can be called a usb-c - micro-usb cable, which is simply necessary for the owners of new technology from Apple.
How to find out if your device supports OTG cable
And now you have a pinout and a heated soldering iron in front of you, but it remains to check the last point, but is your device even capable of supporting such connections that allow you to transfer the battery charge? Or connect third-party manipulators to it? It depends purely on the version of the android and partly on the modules sewn into the accessory, but to simplify your life - there are many testing programs that allow you to determine in a matter of minutes whether the phone is suitable for these purposes. As mentioned, if this is not the case, try updating the firmware version and downloading the driver for the required accessory and you will be happy.
What tools will be needed
Those who did not miss the lessons of labor at school already roughly represent the necessary tools for creating a cable. We only need to cut off the input and output of different charges and connect to each other using soldering, and then electrical tape, so take:
- Nippers or pliers, and be very careful here. Any extra spikes impair the speed of communication between devices, increasing the resistance and decreasing the amperage, respectively.
- A knife or all the same pliers to strip the insulation, besides, you should not remove it completely, as some craftsmen do, a small piece of bare wire is enough, so you will reduce the chance of breaking the chain.
- Soldering iron. It doesn't matter if you have a Soviet device in your hands or a modern soldering iron with automatic shutdown when touching living matter. Remember the safety rules, keep it right. With some skill, you can also use a wood burning device. But it will take a little longer and leave traces of oxidation on it.
There are several tricks that will allow you to do without a soldering iron, which every Soviet child knows about. It is enough to use any filament or a sufficiently thick copper wire, and heat it up separately, while isolating it from direct contact with the skin. But if you have never even held a soldering iron in your hands, it is better not to risk doing it yourself without the help of a specialist.
Remember that the appliance cools down for a few minutes after use and try to prevent rosin and tin from getting on the table, especially if it is made of flammable materials. Try not to burn yourself, you can buy special protective gloves for this.
Soldering
To begin with, a homemade cable should be cut according to the prepared scheme. Measure the required length and do not try to make it as long as possible, this can lead to inconvenience in use. Then strip the wire from the insulation, do not remove too much, this way you will increase the stability of the connection and reduce the chance of occurrence of "fractures" in the solder. And you should not spend a large amount of tin. The neater and more inconspicuous the connection, the greater the strength of the adapter and the charge transfer rate, and when the current strength is measured in 1 A, there is no need for excess resistance.
Having soldered and making sure that the metal has frozen, rewind the bare wire with electrical tape, again - a hundred layers will in no way affect the strength of the structure, so excessive fanaticism should be avoided here.
Check
Having installed all the necessary software and drivers on the phone, try the adapter, if it does not work, check the current with an ammeter. Is there a current? Then the problem is already directly in the smartphone, try testing your homemade product on another accessory or on a different firmware version!
Video instruction
The story of how difficult it was to connect a 4g modem, flash drives and a mouse to the tablet, and even not let it run out of power. Disassembly, tests of springs, Orico cables, a good thing, I recommend, not clause 18. All under the cut)
Hey! Today we are reviewing the mcroUSB-OTG hub with additional power. The review on it has already been on Muska, but very short, I will try to supplement it. It all started when I gave my parents a Prestigio Visconte Quad tablet (8 "", Intel Atom Z3735G, 1GB RAM, 16GB ROM, Windows 8.1 \ 10). What was needed was a windows tablet so that the owners were as comfortable as possible to use, as on their laptop in general. I bought the tablet from a friend's hands, so the equipment was far from original: some kind of frivolous charging 1A and a microUSB cable was the first one that came to hand. As a result, during active use (wi-fi, online video, bluetooth mouse), the tablet was discharged while being charged. Moreover, the modem connected via the 4g otg cable did not start, it appeared in the system, then fell off again at the stage of installing firewood. Thanks to the community on w3bsit3-dns.com, I found out that the modem stupidly lacks current strength. And the whole problem of survival with one microUSB is devoted. And I started making cables with additional power according to w3bsit3-dns.com schemes.
Scotch locks scheme
Hub option
Everything worked, the modem started up, but using such cables was inconvenient, and the design itself did not last long. It was decided to kill all birds with one stone to purchase the factory version and the choice fell on the Acasis H-027. I immediately liked its austere design and modest, but original Acasis markings, which look like if it had been written by Asus, I would not have doubted at all. I chose the cheapest lot at the time and received it 37 days later. There was no instruction in the kit (although some do). All packaging is a bubble wrap and a bag.
The device can operate in three modes:
1. Only charging
2.otg + charging
3. Only otg
A switch is provided to switch between them.
On my tablet, these modes worked like this: 1.otg + charging
2.otg + charging
3. Only otg
The body of the device consists of two halves, fastened by the thorn-groove method. When disassembled, the thorns suffer and heroically fall off. Everything inside is clean and tidy.
The hub is controlled by the fe 1.1s microcircuit, very cheap, it can be found in many usb 2.0 hubs with Ali, from very solid models to copies that literally fall apart in the hands. You can often find it in inexpensive Chinese tablets.
The indicator light signals that the power is connected. Implemented not very sensibly - just a hole in the case.
Otg-mode works flawlessly, I did not measure the speed of copying from drives, everything is normal there. Otg + charge mode with Orico colorful 0.5m cable
with three flash drives
with screw and flash drives
With a 4g modem, everything is also correct. Basically, for powering the tablet and the hub, I use a Robiton charger and an Orico microUSB cable 2m long.
In the maximum possible option: memory + 2 meters of cable + hub with a screw, modem and mouse, the tablet is slowly but charging, otg works i.e. the hub fulfills its purpose. Nevertheless, let's take measurements.
without a hub with a load of 1A
with hub and load 1A
If you have an extra USB stick, you can easily convert it to an OTG USB stick so you can connect it to your smartphone or tablet without having to carry a USB OTG adapter with you. You can of course just buy such a device from the Internet or a store, but I would like to make my own, since it is easy, and I have all the necessary components and the OTG cable circuit.
There is a risk of damaging your flash drive or smartphone / tablet, be careful when laying and soldering wires, if possible, it is better to check for the first time on a cheap smartphone. I warned you.
To unsolder OTG you will need:
- Regular USB 2.0 flash drive with a soldered connector (free)
- USB-OTG adapter (should cost less than 100 rubles)
- Continuity Multimeter
- Soldering iron with solder
- Basic soldering and multimeter skills
- Knife (to open the flash drive)
- Silicone sealant, Sugru (rubber clay), hot glue or insulating glue
- Cutting tool
- Electric drill or dremel with 2mm chisel
- (Optional) USB Type-A Male (Male) to check pinout
Step 1: choosing a suitable USB stick
The first thing you need to do is select a USB stick with a soldered connector. Not all USB drives are the same, and the only way to find out is to open it. Use a knife or screwdriver for this.
[Photo 2-5] is a Chinese flash drive in a stainless steel case. As you can see, this ultra-thin flash drive is packed with plastic, there is no soldered connector.
[Photo 6-8] is another flash drive from China. She has a board with a connector, I will use it. Please note that the "dirty" solder in the connector is due to the fact that I have already soldered this flash drive.
Step 2: cut the USB-OTG adapter
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[Photo 1-2] On my model USB-OTG adapter, I can simply pull the bezel of the USB port to show you what's inside.
[Photo 3-5] Measure the length of the cable required for your USB stick. Don't cut the cable too close to either end, we'll need both. The yellow stick is just for example.
[Photo 6-9] Using a cutting tool, carefully open the wire and separate the inner four wires. This must be done so that they can fit inside the flash drive when you assemble it.
Step 3: check the pinout of the OTG adapter
Currently USB-OTG adapters use 4 wires. Two for power and two for data. You need to make sure you solder the correct wire, or else you could damage your $ 500 smartphone from the $ 2 project.
Using the multimeter and the USB connector (mother) that we just cut off, we can determine the pinout of the OTG cable. Usually the colors are red, white, green, black, but not always in that order, or maybe even at all, you will have other colors.
Pay attention to the OTG pinout diagram, that in the photo, if you use the input connector (female), then the order of colors will be reversed!
[Photo 4-5] I used a male (downstream) USB connector to make testing easier. On the Internet, it costs less than a hundred rubles.
[Photo 6-7] This is my meter reading when it is in continuity check mode. Pay attention to the correct orientation of the wires and connector. Double check the order and refer to the USB pinout diagram if in doubt.
Step 4: soldering
Now it's time to solder the wire. Prepare a soldering iron and solder. Solder all 4 wires.
CHECK TWICE THAT IS NOT A SHORT CIRCUIT, not on one of the wires you just soldered. Also make sure the wires are not too close together. At the current stage, it is impossible to verify the correctness of the pinout, so if you feel that you have made a mistake, it is better to stop than to damage your smartphone or tablet.
Step 5: preparing and assembling the case
[Photo 1-3] This is a simple step. First, you need to drill through the case of your USB drive. This is done so that the OTG cable can come out of the back of the flash drive. I used a 2mm drill bit, but I think 3mm would have been better.
[Photo 4-6] The next step is to make sure that the insides of the flash drive do not move. Each time you open it and put it back together, there is a chance that the former density of the assembly will disappear. So I decided to use double-sided tape to keep nothing moving. You can use Blu-tack plasticine, Sugru, hot glue, or something else.
I also covered the wires near the connector with silicone sealant so as not to worry about them touching each other and causing a short circuit. This is optional, but I highly recommend it. I don't know if Sugru or Blu-tack have insulating properties, but if in doubt, silicone sealant and hot glue are great.
Step 6: That's it!
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When the work is done, let's first insert the OTG USB stick into the computer. The reason I chose the computer is because on motherboard most computers have short circuit protection.
Then I tested the drive on the tablet, via USB and OTG. Everything worked fine. In the end, I inserted it into my android smartphone (LG G4), it still worked fine, the device was displayed in file manager... Please note that most Android devices do not support file system NTFS, so format your flash drive with FAT32.
Here you go! Homemade OTG-USB drive works! At the same time, it was very cheap!
I want to warn you, as this is a simple "parallel" wiring, NEVER ATTEMPT TO CONNECT BOTH ENDS [PHOTO 7].
[Photo 8-10]. Now you know how to make your own OTG USB stick. Here are photos of my homemade OTG hub. It is made with the same disassembly and solder method, even the cable is the same. I have been using it for over a year now without any problems.
I talked about choosing a tablet, and in particular about such a necessary function for me as the ability to connect various USB devices to it, such as: flash drives, a card reader (and accordingly memory cards of different formats), etc.
So, having bought a MoveO tablet! TPC-7HG I suddenly encountered a problem completely unexpected for me. The thing is that this tablet has only a mini-USB connector. In itself, this was not a surprise or a problem for me - on the contrary, it is easier to find a standard mini-USB cable in order to replace, for example, a failed charging cable on occasion. An unpleasant surprise for me was that in my town nowhere - ANYWHERE! - mini-USB OTG cable was not sold! It also did not come with the kit. Going to all possible and impossible stores, I came to the conclusion that, perhaps, it would be easier and faster to make such a cable with your own hands.
ATTENTION!!! EVERYTHING YOU DO - YOU DO AT YOUR OWN RISK !!!
And now a little theory. You cannot simply take and solder together a mini-USB plug with a piece of wire from one cable and the so-called USB female plug from another cable. No, that is, of course, you can solder something, but just connect to the tablet and make it work with this cable not a single device will work. Here's the thing.
The standard mini-USB cable has a five-pin plug:
001.
Contacts in it are numbered as follows:
002.
But there are only 4 wires in a standard USB cable. Where did the fifth wire go? Yes, nowhere. It simply does not solder to the end switches of the connector!
The purpose and color marking of wires in a regular USB cable are as follows:
1 - Red VBUS (+ 5V) +5 Volts constant voltage with respect to GND. The maximum current is 500 mA.
2 - White D- (-Data)
3 - Green D + (+ Data)
4 - Black GND - common wire, "ground", "minus", 0 Volts
The main difference between the USB OTG cable is the plug. In a mini-USB OTG cable (however, as well as in a micro-USB OTG cable), pins 4 and 5 are closed together. In a regular (not OTG) data cable, a wire is not soldered to the 4th pin of the plug. This plug is called USB-BM mini (micro). If you solder pins 4 and 5 together, then such a plug will be called USB-AM mini (micro). It is by the presence of a jumper between 4 and 5 contacts in the USB-AM micro plug that the tablet determines that a peripheral device is going to be connected to it. If this jumper is not present, then it will act as a passive device itself and will not react to any kind of USB devices connected to it.
So, we got acquainted with the theory - let's get down to practice.
We take a regular mini-USB cable, carefully open its connector with a clerical knife. As a result, we get the following set of young technicians:
003.
Next, we need to connect the 4th and 5th pins of the plug. This can be done, for example, by carefully peeling off the sealing plastic from the back of the connector. But here two are waiting nasty surprise... Firstly, it turns out to be not so easy to do without damaging anything, because the contact group is poured into conscience - you dig out the hell. The second "surprise" is the short contact of the 4th contact (forgive my pun!), Which makes it extremely inconvenient to solder something to it:
004.
Honestly ruining the first cable, I take on the second one, but I am doing it a little differently. Having opened and disassembled the mini-USB connector, from the back of the contact pad, using the same clerical knife, I neatly scrape off the plastic in the area of the 4th and 5th contacts right down to the contacts themselves:
005.
Now we take a soldering iron and put a neat jumper between these two contacts with tin.
006.
The only thing you need to watch out for here is to keep the contact pad as flat as possible, and both from this side - since in this case our connector may simply not fit back into its metal case, and from the opposite (that is, actually from the side of the contacts) - since the unevenness there can lead to the bend of the contact group of the tablet socket, and this is already fraught. Having made a jumper, you need to take care to avoid short-circuiting the freshly soldered contacts with the connector body. To do this, I used such an indispensable tool as Poxipol.
007.
Please note that only TRANSPARENT Poxipol has electrical insulation. The metal Poxipol has quite conductive characteristics and, of course, cannot be used in this case.
After the Poxipol has hardened, the excess can be cleaned off with a knife and the USB connector reassembled:
008.
In principle, it would be nice to fill it with Poxipol from above, but I recommend doing this after the cable has been tested for operability.
And we cut off the USB-female connector from it with a piece of wire:
010.
Now we only need to connect the two received cables (one with the mini-USB connector, the other with the USB-female connector) together.
First, we "dress" one of the wires with heat shrinkage:
011.
Take the soldering iron again:
012.
And carefully solder (from the word "solder" and not "solder"!) The wires in the cables.
013.
To isolate the wires from each other, I used the same Poxipol. And when he froze, he put it on top together with heat shrink:
014.
As a result, we got such a cable.