Buy an otg cable with additional power. What is an OTG cable and its features

The USB OTG cable is an interesting accessory that you might find useful when used with your tablet or . What prospects does it open up for us and what opportunities will become available when using it? And what does “OTG” even mean? These questions are often asked by users who hear about this kind of cable for the first time. Let's find out more about it.

How to use a USB OTG cable for your Android tablet or smartphone

In general, OTG is an abbreviation of On-The-Go, which means “on the go” in English. This is a USB 2.0 extension technology. With it, you can, flash cards, printers, keyboards, hard drives, cameras and other peripherals without connecting to the computer itself. The only condition is that your device must support this feature at the hardware and software level.

If you connect according to the USB OTG standard, the abilities of the master (power source) and slave (power consumer) gadgets are assigned by whether it has a jumper between the fourth and fifth pins in the cable connector for connection.

There is also partial support for USB-host devices on Android (mostly smartphones), when your gadget can control the device without powering it. Then the auxiliary electronics are connected using an active USB hub, which has its own power supply system. How can you use such a miracle cable?

Examples of using USB OTG cable

There are a huge number of ways to use a USB OTG cable. Let's look at the most popular of them.

But it happens that you don’t have such a cable now, but look for the nearest store mobile accessories no time, no desire. Well, in this case, you can try to make such a cable yourself. Although this procedure is more intended for professional people.

Making a USB OTG cable with your own hands

Don't rush to rejoice so quickly, because you still have to go to the supermarket or radio store to get a whole list of different things!

First, using a sharp knife, you need to open the microUSB connector. The meaning of the action is to carefully divide the connector sleeve lengthwise into two equal parts in order to gain access to its internal contents. But it happens that the connector body is held on by simple latches or even glue. Then you will not have problems with separation. But in the first case, you need to be extremely careful: you cannot destroy the outer sleeve of the connector, since in the future it will still be used. You can also find white plastic inside that protects the necessary wires. In this case, you will need to cut through it.

Now you can move on to the next step. Having opened the connector contacts, you will find that their number is not four, but five. Basically the four pins are +5V power, two data wires D+ and D-, and ground. And the fifth wire, not connected to anything, is the mode switch input (sense). It must be connected to the ground before connecting to the device, in order for it to switch to OTG mode and detect a USB device connected to the interface. The image below shows the differences between regular cable and OTG.

So, to transfer the gadget to OTG mode, you need to close the fourth and fifth contacts. If you want to “deadly” connect them, you can solder them together or connect two wires to them (we bring these wires out and connect them to a microswitch, with which you can perform I / O operations in OTG mode if necessary). Then, on the opposite side of the cable, it is necessary to solder Type A Female (second type) in parallel with Type A Male (the first type of connector). In addition, you can build a small adapter with two Type A Females for its further connection to the opposite part of the cable. Having decided to connect the fourth and fifth contacts permanently, it is necessary to replace the first type connector on the opposite side with the second one so that it is suitable for connecting a USB device.

I talked about choosing a tablet, and in particular about such a function that I need, such as the ability to connect various USB devices to it, such as: flash drives, a card reader (and, accordingly, memory cards of different formats) and so on.

So, having bought a MoveO! TPC-7HG, I suddenly ran into a problem that was 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, if necessary. An unpleasant surprise for me was that in my town nowhere - ANYWHERE! - mini-USB OTG cable was not sold! It didn't come with the kit either. 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 some theory. You can’t just take and solder together a mini-USB plug with a piece of wire from one cable and the so-called USB-mother plug from another cable. No, that is, of course, you can solder, but just connect to the tablet and make it work with this cable, not a single device will work. And here's the thing.

The standard mini- USB cable five pin plug:
001.

Contacts are numbered as follows:
002.

But a standard USB cable has only 4 wires. Where did the fifth wire go? Yes, nowhere. It simply does not solder to the connector limit switches!

The purpose and color marking of wires in a regular USB cable are as follows:

1 - Red VBUS (+5V) +5 Volts of DC 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 Volt

The main difference between the USB OTG cable is the plug. In a mini-USB OTG cable (as well as in a micro-USB OTG cable), pins 4 and 5 are closed to each other. 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 pins 4 and 5 are soldered together, then such a plug will be called USB-AM mini (micro). It is by the presence of a jumper between 4 and 5 pins in the USB-AM micro plug that the tablet determines what they are going to connect to it peripheral device. If this jumper is not present, then it will itself act as a passive device and will not react to connecting any kind of USB devices to it.

So, we got acquainted with the theory - we proceed 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 on the back of the connector. But here two unpleasant surprises await. Firstly, it turns out to be not so easy to do without damaging anything, because the contact group is poured on the conscience - you pick out the hell. The second "surprise" is the short contact of the 4th contact (forgive me my pun!), which makes it extremely inconvenient to solder something to it:
004.

Having honestly ruined the first cable, I take on the second one, but I deal with it a little differently. Having opened and disassembled the mini-USB connector, I use the same clerical knife to carefully scrape the plastic around the 4th and 5th contacts up to the contacts themselves with the same clerical knife:
005.

Now we take a soldering iron and put a neat jumper between these two contacts with a tin.
006.

The only thing to watch 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 unevenness there can lead to bending contact group tablet sockets, and this is already fraught. Having made a jumper, care must be taken to avoid short circuit 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 insulating means. The metal Poxipol has quite conductive characteristics and, of course, it cannot be used in this case.

After Poxipol hardens, the excess can be cleaned off with a knife, and the USB connector can be assembled:
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 cut off the USB-mother connector with a piece of wire from it:
010.

Now we only need to connect the two received cables (one with a mini-USB connector, the second with a USB-mother connector) to each other.

First, we “dress” one of the wires with heat shrink:
011.

We take the soldering iron again:
012.

And carefully solder (from the word "solder" and not "drink"!) the wires in the cables.
013.

To isolate the wires from each other, I used the same Poxipol. And when he froze, he put everything together on top with heat shrink:
014.

The end result is this cable.

If you have a smartphone or tablet based on operating system Android, you might want to use it as a host for some ham radio like an Arduino board.

This will require not just a USB cable, but On-The-Go (OTG) USB. You can buy one from a radio store or order online, but if you're too lazy to go shopping or don't feel like waiting for the package, you can make your own USB OTG cable as it's quite simple.

First, you will need two USB cables as donors. One of them must be type A with a female connector, and the other type micro B with a male connector. When you're done, you'll have a cable that connects to your phone on one side and can connect to a standard USB cable on the other side.

But first, cut these two donor cables so that you expose the red, black, white, and green wires that go inside these cables. Strip the insulation from the ends of these wires. Match the colors of the wires of one and the other cable and solder them to each other. Isolate the solder joints from each other with heat shrink tubing, duct tape, or hot glue. Be sure to cover them with braid, which is bare stranded wire that surrounds the four colored wires.

After you have soldered the two cables together, wrap electrical tape around the joint for electrical and strain relief. Since many Android phones are USB OTG devices, that is, they can act as a USB host or slave, you still need your phone to act only as a host in this case. You can verify this by using a special sensitive pin in the micro B connector. When this pin is connected to ground, USB device The OTG connected to the cable goes into host mode. If the pin remains in its normal disabled state, the USB OTG device will remain in slave mode.

Now carefully open the micro B connector cover and solder pins 4 and 5 together. Once this is done, reassemble the micro B connector by putting the cover on it and securing it with electrical tape or glue to secure it.

To make sure everything works as it should, test your homemade cable by connecting one end to your Android phone or tablet and the other to your Arduino. If everything is set up correctly, then the Arduino should turn on as it will be powered up. If this does not happen, then disconnect both ends of the cable and check it for a short circuit or open circuit. Keep in mind that you won't be able to test the transfer capability until you write the appropriate programs for the phone and Arduino.

Not all old tablets support the function of connecting a flash drive or modem, but I will tell you how to outwit them and connect a flash drive, modem, and even HDD.

Today I want to bring to your attention OTG - an adapter.

First I want to tell you what is OTG? This is a way to connect to your tablet or phone that supports OTG function, printer, flash drive and even hard drive. This connection is also called USB-host.

You can also connect a keyboard or mouse to your gadget, if the gadget supports such a function.

And so, to create this miracle cable, we need:
Old USB extension cable
Micro USB connector (available from conventional USB cable for your device)
Soldering iron and soldering accessories

And so, let's go, in order for us to make such a cable, we will need to connect the 4th pin to the 5th pin of the micro USB connector

We need to get to the fourth pin and connect it with a jumper to the GND wire as shown in the picture.

After we connect the 4th and 5th contacts with a jumper, our gadget will perform the function active device and will understand that another passive device is going to be connected to it. Until we put a jumper, the gadget will continue to act as a passive device and will not see your flash drives.

But that's not all, to connect a hard drive to a phone or tablet, this adapter will not be enough for us. To connect devices whose consumption is more than 100mA, namely 100mA, the port of your device can give out, we will need to connect additional power to our OTG cable, which should be enough to make your hard drive work.

Here is a diagram of such an adapter

Now it's time to start collecting
We take an old USB extension cable and cut it not very far from the 2.0 connector, since the current is only 100mA to avoid large losses. Cut off approximately in the place as shown in the photo

After we clean our wire

I connected with a drop of solder 4 and 5 pins.

Well, here is our entire cable assembly

It remains only to check the performance, take the tablet, insert the “adapter” and insert the USB flash drive into it, everything works, as the flashing LED on the USB flash drive and the tablet identifying the USB flash drive tell us.

Almost any manipulator connects 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 just need to connect a keyboard to a tablet or smartphone?

For this, there are otg cables, which in fact are just abstrusely 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 layman: how to make such a device yourself, so as not to spend money? Fortunately, for this, an old charge 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 settings are made using the internal software of a tablet or phone, therefore it is just a cable with an 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 is it necessary 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 you pick up a soldering iron, you should understand 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 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 device for recharging. So, you find yourself in a situation where the laptop is almost dead, but the phone is 100 percent, and here you will need otg support.

Yes, 2-4 batteries thousand mAh enough for a while. But when it comes to urgently answering a letter or sending a project to the authorities, the time count is already running in 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 taking on the joys, cut off the nearest old charger, make sure you have a soldering iron and a tin. In fact, the same OTG can be called usb c cable- micro-usb, which is simply necessary for the owners of new equipment from Apple.

How to know if your device supports OTG cable

And now you already have a pinout and a heated soldering iron, but it remains to check the last point, but is your device even capable of supporting such connections that allow you to transfer 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 already mentioned, if this is not the case, try updating the firmware version and downloading drivers for the necessary accessory and you will be happy.

What tools will be needed

Those who did not miss labor lessons at school already roughly represent the necessary tools for creating a cable. We only need to cut the input and output from different charges and connect them together using soldering and then electrical tape, so take:

1. Nippers or pliers, and here you should be very careful. Any extra spikes degrade the communication speed between devices, increasing the resistance and decreasing the current strength, respectively.
2. A knife or all the same pliers to strip the insulation, moreover, you should not remove it completely, as some craftsmen do, a small piece of bare wire is enough, so you reduce the chance of breaking the chain.
3. 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 device for burning wood. But it will take a little longer and leave traces of the oxidative process 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 thick enough copper wire, and warm 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.

Do not forget that the device cools down for several minutes after use and try to prevent rosin and tin from getting on the table, especially if it is made of combustible materials. Try not to burn yourself, for this you can buy special protective gloves.

Soldering

To begin with, a home-made 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 may lead to inconvenience in use. After that, 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 “breaks” in the solder. Yes and spend a large number of tin should not. The more accurate and inconspicuous the connection, the greater the strength of the adapter and the charge transfer rate, and when the current strength is measured at 1 A, there is no need for extra resistance.

After soldering and making sure that the metal is 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.

Examination

After installing 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