[Solved] USB OTG Host Adapter with Smartphone/Tablet Power Supply & Charging Capability

You need to connect the USB device to D + and D- and the power supply is to come from an external power supply. As you know, OTG should be properly shorted the pins so that the device gives power, but you do not do it because the power is to come from the outside. I saw a description of this somewhere.

I found something like this:


The photo shows the Charge / OTG switch, i.e. we either charge the phone or power the peripherals connected to it.

On the well-known auction site you can find under the entry: HUB micro 3x USB OTG Splitter + charging

After all, it is known that this is not the case, because the author of the topic wants to have the phone and OTG charged at the same time.

There are special OTG Y cables.

When ordering, ask the seller if it will work with your phone.

What's your phone?

After all, the Galaxy S5 has a micro USB connector.

Chilek wrote:

I know it is possible, because I once bought such a connector on Allegro, but it only worked in one model and when I changed the phone it became useless.

Unfortunately, in my opinion it depends on the phone model. OTG itself also has several versions.


Source: Link

Chilek wrote:

I don't think you understand what I mean.

Then kindly explain what you mean.

E8600 wrote:

OTG itself also has several versions.

You tell a very interesting story

Freddy wrote:

E8600 wrote:

OTG itself also has several versions.

You tell a very interesting story

The point is that some phones with OTG also have MHL to connect to HDMI and then the equipment can support something like charging while entering OTG or MHL mode.

There is one more issue with this connection, I do not have a quick charge, only max 500 mAh. It is the current that sustains the battery so that it does not discharge and does not charge. With intensive use, despite the charging icon, the percentage of the battery will drop down.

One more issue of these cables is tablets on Winowsie do not have something like OTG and there it can really work on Android, it will not be so rosy.



Below the same without any special OTG cables.

OTG, or On The Go, is a standard that allows you to connect many different devices to smartphones and tablets.
MHL, or Mobile High-Definition Link, is a signal transmission standard for mobile devices (max 1080p).
Do not confuse both standards - MHL is not an OTG device!

What you showed is a USB extension with resistor and power supply that is neither OTG nor MHL connectable.

Regarding charging, each OTG cable only allows a 500mA charging current, because it cannot be larger.
The USB OTG Y cable will look like below.


No OTG cable allows MHL connection. The MHL cable requires all five wires to be connected.

What the colleague presented will also not work because the LED in this place is no power to USB devices.

I did not write that OTG and MHL are the same, only that devices with MHL allow charging and such devices can also be charged with OTG in others, you will probably need to unlock something in the software.

You can and without a diode, and it is only for devices with their own power supply.

E8600 wrote:

that devices with MHL allow charging and such devices can also be charged using OTG

Like MHL, they are not OTG, there are MHL cables with additional power supply and you do not need to combine anything in the software.

Either I wrote it wrong or my friend did not understand.
Devices having MHL are more likely to support charging over an OTG connection. On the other hand, devices with OTG only may require unlocking the charging in the software (in some, even unlocking it will not help at all). These are the discrepancies in the GSM market, the same OTG standard, but it works differently depending on the model.
It was similar with some phones (eg S3 mini), namely theoretically they did not support OTG but it could be unlocked in the software, unfortunately they required additional power supply.

In some model, the Sony could be connected so that the phone was charging itself from its own OTG port without an external power supply. "Loading" means there was a loading icon but the% did not go up, but rather down. :)



As for the thrown diagram, it is this 100k resistor that gives information to the phone that it is to enter the OTG mode with charging. Unfortunately, this is a patent mainly for Samsung and for others it may not work or it will be a different resistor value.
Link

Brands use similar circuses with resistors in order not to use substitutes for chargers. I met something like this with some HTC and Galaxy Tab.

I will only add that I did not check the scheme personally because I have a different phone and I did not have such a need. However, if someone checks, it is welcome info that this is a department taking into account the phone model.

E8600 wrote:

Either I wrote it wrong or my friend did not understand.
Devices having MHL are more likely to support charging over an OTG connection.

I can see that you are stubborn despite the evidence provided.
Again, MHL will not work with an OTG cable as it requires all five wires!
The OTG standard clearly states what the conditions should be, and the fact that someone managed to get a 100k resistor is a coincidence.

E8600 wrote:

I will only add that I did not check the scheme personally because I have a different phone and I did not have such a need

If you haven't checked, then don't give it because you're misleading.

Freddy wrote:

Again, MHL will not work with an OTG cable as it requires all five wires!

I have never written anywhere that we can have MHL and OTG connected at the same time. I just meant that devices with MHL have a more written USB protocol from the software side. Which increases the chances of being able to recharge with an OTG connection.

Freddy wrote:

The OTG standard clearly states what the conditions should be, and the fact that someone managed to get a 100k resistor is a coincidence.

Yes, but there was a problem of discharging the battery even faster with a standard OTG connection (connection of pins without a resistor) and manufacturers have introduced something like a new OTG standard with the possibility of charging, and in the case of Samsung and Sony, the 100 k resistor is the key.

Enjoy reading.
Link

And here are some more advanced schematics from the docking station with charging and simultaneous OTG with an active hub. By the way, I myself felt like such a station, but I do not know if my Blackberry Z30 supports charging with an OTG connection. I have to test in my free time. As I have a full micro HDMI in my phone, on such a station it could be used as a PC when connected to a monitor.
Link
The resistor must be exactly 100k high tolerance as it is written in this article (98K or 103k will not work anymore).