Iconia W4 - Charging whilst using USB devices

I recently purchased an Acer Iconia W4 in hopes of implementing a compact windows element into my application; unfortunatley my application requires the Iconia to maintain a succesful data connection to a powered usb hub while being charged, regardless of how fast or slow the charge rate is - a constant power source is key. From what I've gathered there hasn't been much support on this USB issue, unlike that of other tablets such as the Venue 8 and Encore 8 where solutions have already been proposed. Note that when I first purchased this product I previously owned a W3 which did have this capability (simply connecting a powered usb hub would charge and also supply data via USB 2.0), so after buying the W4 and realizing that it could not reproduce the same result made me a little confused.

I personally have tried to implement the Venue 8 solution shown here:

Venue 8 - USB charging and data solution

but to no avail... perhaps the Iconia W4 usb port is innately different to that of the Venue 8? The idea of the above schema is to short the data pins to initiate charging on the tablet, thereafter unshorting the data pins would provide usb data and charging.

I have not tried this method (second last post of the thread - post made my Diversion40) yet for the Encore 8 but intend to in the coming days.

Has anyone else encountered this issue with the W4, or better yet found a solution to it? Obviously it would be great if I could simply plug in a powered usb hub into the usb port like the W3, but so far I have not found a hub that works with the W4, at least one that can provide charging and data. Does Acer produce OTG Charging and Data cables such as Samsung's? or does anyone know of a powered usb that works with the W4?

Any help or suggestions is greatly appreciated!

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Ryanrr

The problem you are coming across is actually a limitation of the device. I apologize as I am unable to assist with the work around you have tried as it consists of several 3rd party adapters and that is not something we support.

padgett

I have a different 8" Bay Trail because I needed GPS but they all (except the Dell) seem about the same.

Mine cannot charge while using the USB but it can run on AC and if I start the day with 95% it will end the day with 95%.

Does require a Startech USB2HAUBY3 Y-cable and a Fem-Fem USB-A gender changer.

Have run it with either a Gearhead powered hub or a Targus Dual Display dock or from a wall wart. Any supply of at least 2A will probably work. Have even used an iPad charger.

(rant) why the companies cannot realize the profit potential from accessories like this is beyond me but wish they would at least document "plugged in, not charging"(/rant)

ps this is a plain power/data cable. So far I have not been able to make an OTG cable work. May be me.

pps have gotten it to charge by shorting the data leads together but must unplug, replug to be recognised (and sometimes have seen it take up to 30 seconds for the tab to realize something happened).

justinsswong

Thank you for both of your replies.

I really like your setup Padgett and was thinking of attempting something similar. I tried the Encore and Dell solutions but I can't seem to get the W4 to allow charging while using USB. Just to clarify, do you suspect that your setup should work with the iconia W4? or have you actually got it working with the W4? I don't need my tablet to charge either, but it must not lose power insomuch that the tablet's battery supply becomes depleted - ultimately I would like the tablet to be able to run 24/7.

padgett

I don't have a W4 (needed GPS) but do have another 8" Bay Trail tab. All except the Dell use the same chipset and I have seen a lot of mix and matching of drivers between sites.

That said I have had comments from a number of people that other Bay Trail tabs would run on ac (not charge but not deplete the charge either) as describled. You do need at least a 2A (10W) supply.

If working properly the tab goes into the undocumented "plugged in, not charging" state and you can connect USB devices though a powered hub or Dock. Whatever the charge was, it will be the same even hours later (mine has been at 94% since this morning)

Should mention that I tried a number of Y cables including a very nice OTG one and the Startech is the only cable I have found that works reliably. That the power end is red is just a side benefit.

Will mention that before I connected to the same hub/doc for both power and data I verified that the polarity of the 5v was the same first. Probably belt and suspenders.

Really wish the mfrs would document this but may be under direction from "Someone" not to but suspect the message is coming from the ACPI driver. Seems like a profit opportunity for someone.

That said have solutions to both the "run on ac while using USB" and "using legacy GPS programs" for the tabs now. Too bad I do not have a store.

HK53T

what about something like this?

DealExtreme - Micro USB Male to 2-Port USB 2.0 Female + 1 Micro USB Female Charging HUB - Black

http://dx.com/p/micro-usb-male-to-2-port-usb-2-0-female-1-micro-usb-male-charging-hub-black-243246

padgett

No idea, I just had to experiment to find one that worked. It says "supports OTG" whatever that means but this did not work.

justinsswong

Thanks for the info Padgett and apologies for the delay as I've been busy travelling.

I have two questions regarding your solution:

1. What does the " Fem-Fem USB-A gender changer" do?

2. What do you mean by "I verified that the polarity of the 5v was the same first"? Are you verifying the polarity of the power adapter or the usb socket?

Appreciate your assistance

wmm

justinsswong wrote:
Thanks for the info Padgett and apologies for the delay as I've been busy travelling.

I have two questions regarding your solution:

1. What does the " Fem-Fem USB-A gender changer" do?

I have the same setup he does (copied from his posting on the Toshiba Encore support board). The StarTech cable we use is intended to support peripherals that require more current than can be supplied by a single USB port on a computer. As such, it has two male full-size USB plugs and a male micro-USB plug. The idea is that you plug both full-size plugs into the computer; the red plug only has the power leads connected, while the black plug has both the power and data leads connected. This allows the USB port to which the black plug is attached to control the peripheral to which the micro-USB plug is attached, while power is drawn from both ports on the computer.

In this application, however, the micro-USB is connected to the host and the red plug to the external power supply. That means if you want to connect a USB peripheral or hub (which have male plugs), you have to use the other (male) full-size USB plug. That won't work, so you need a female-to-female gender changer to make that connection.

wpbear

Does this setup work or just in theory? Has this been tested on the Acer W4?

padgett

It works on my 8" Bay Trail tab but I needed GPS so did not buy the W4 and was not part of the eval.

I suspect that somene here has tried it with the W4 & have been told it works on the Lenovo.

Should be able to get both for about U$10 on Amazon.

scosgt

The W4 does not have an OTG port. You do NOT need an OTG adapter, it will recognize and run any powered USB hub! All you need is the $7.00 hub from Microcenter (with a 2+ Amp power adapter) and a converter plug to fit the micro USB port. It does not charge, but it will run all kinds of devices with no problem.

I am unable to confirm the "undocumented plugged in mode" mentioned above. Plugged into a powered USB hub OR OTG hub, it still discharges.

You do not need to power the hub to run a flash drive, or wireless keyboard or mouse. However, a portable hard drive does require power to the hub.

moretoyswins

I have tried to test the Startech setup on the Acer W4-820 and was not able to get it working as described. If anyone else was could they please provide pictures. I am really starting to regret buy Acer how could this use case not make the design table?

Thanks in advance.

dahoutman

Both my colleague and I bought the Acer Iconia W4. Ity was dissapointing that it was not able to use the usb for hosting devices while charging. My ccolleague has invented a circuit that does charge the tablet while using the USB. I made it myself and it works.

Charging whilst using usb

padgett

And the circuit is ??? I have seen that message before when it was just sitting there. Does the charge level increase is the question ? Did you use a button to short the data lines ?

dahoutman

I made the circuit myself yesterday and it is definitely charging while using the usb. This was important for me because i want to use my FocsRite 2i2 with the tablet to listen to my music and Spotify. After a while the tablet was almost fully charged. There is a drawback, however. When I came back from Sinterklaas yesterday, the tablet was at 20% without listen to any music. I thik this is due to the charging circuit inside the tablet. When the tablet is fully charged, it shuts down charging and when the level is below a certain treshold it starts charging again. Maybe the tablet is not able to start charging again. I now do a few test to verify this behaviour.

This is the circuit. The resister is 220 Ohm. There is one double pole switch. If one pole switches off, the other pole has to switch on. So ther one state where the circuit starts to charge. If the tablet charges you can switch to the other state and you can use the usb.

Circuit

scosgt

Hate to bring this up, but Microcenter has the Winbook 10.1" tablet for $199 and the 8" for $139

Both are essentially the same as the W4 hardware wise, BUT

They have a full size USB 3.0 port.

Along with a micro SD port AND the charging port is ALSO a USB 2 port. AND HDMI

So, no charging issues at all.

Screen is just as bright and IPS

Speakers on the large one suck a little bit, the 8" is supposed to be louder.

They also sell a 1 gig/8 gig 7" model for $59 with the full size port and HDMI, so depending on your needs, it may be time to retire that W4

padgett

Two issues with Winbook:

1) No GPS (I consider essential for a tablet & will pay more).

2) "Available for In-Store Pickup Only." and no stores in Florida

scosgt

The Lenovo Miix 8 has GPS. It is basically useless. Nothing works with it.

Since Winbook has a USB port, you can easily use some kind of dongle that actually works with GPS programs.

Maybe you can find one on Ebay.

Plastixx

Well, I guess I'll be the guinea pig for the charging dongle from Dell (470-ABES) since I don't think anyone has tried it with the W4 yet. For $20 it's no big loss if it doesn't work and I'm sure I can resell it on ebay.

There's a coupon right now for Dell accessories that gives 10% off + free shipping. It even let me choose next day day shipping as the free shipping option. Smiley Happy