[Hans]

Hi Chris,

thanks, I have seen the video.

I have looked at the extended Intel Datasheet (http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-z8000-datasheet-vol-1.pdf), on page 17 you can see that the USB support on the Z8300 is limited in comparison to Z8500 and better. USB 3.0 is only listed as OTG, while USB 3.0 is available on to 3 devices on the 8500 . See attached excerpt from the sheet.

Chris, does any of your x8300 tablets support USB 3.0?

There must be some USB 3.0 support because the Intel Compute Stick with Z8300 contains one USB 3.0 port. None of the reviews I have found online did test the speed of the USB ports (e.g. http://www.legitreviews.com/intel-compute-stick-stk1aw32sc-review-cherry-trail_177761).

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[Hans]

today I got 2 other USB-C USB 3.0 Hubs. It is the same problem as with the other two hubs: Either they don’t get detected (usb device error in Windows) or if they work, only USB 2.0 devices work, any connected USB 3.0 will not work at all. I have read the answers in the thread here and I would say any USB-C hub does not work.

I also got an USB-C to USB-A adapter (without hub Victsing USB C to type A adapter) and this works. If I connect a USB 3.0 hub, then only the USB 2.0 devices work (same as with the USB-C hubs). USB 3.0 devices that are directly connected to the C-A adapter work with USB 2.0 speed.

Also the connection is only USB 2.0, I get 41 MB/s. I have used USBTreeView (http://www.uwe-sieber.de/usbtreeview_e.html) and it tells me on port 1 (that is the port that is used if a usb device is connected) that USB 3.0 is not supported, bummer. I have played with the BIOS settings without success. This odd, since Windows tells me that an XHCI 3.0 adapter is present.

This is very disappointing, a typical use case for me is copying memory cards.

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[Hans]

I did some research on the USB specifications from usb.org. Having an USB-C connector does not mean much. There are many optional features, like USB Power Delivery (PD), alternative mode etc. I don’t think that the tablet supports USB Power Delivery. Overall USB-C looks like a huge mess with a lot of invalid cables and accessories in the wild.
It seems that there is no easy way to examine the capabilities of an USB port from Windows or see what the cables support.

Building a USB-C PD capable cable requires dedicated chips that tell the capabilities of the cable to the device. And the ICs are tiny (google for USB Power Delivery IC or USB Power Delivery PHY). So nothing to hack onto the Chuwi. It also needs to communicate with the USB port. I am not sure if the OEM USB-C cable operates correct, since Windows complains that the USB device was not recognized when I connect it while Windows is running.

It would need to reverse engineer the power supply circuit. I don’t want to take the mainboard out, since it is glued. Maybe a dump approach like applying 5V directly to the corresponding rails does work, but I doubt it. Somehow the tablet needs to know that a charger is connected.

I have order two more hubs and a USB-C to USB-A adapter cable. I will post the results. This one here does not work at all:

http://www.banggood.com/USB-3_0-Type-C-3-Ports-Hub-Data-Sync-Charging-Adapter-Aluminum-For-MacBook-p-1005118.html?p=QZ14021624945201505Y

Maybe we should create a google doc and collect things we have tested?

[Hans]

well that does not create a lot of confidence. Mine is serial 4000 something. I have noticed some Android things in the BIOS. But return to the manufacture to install it? Does not make sense.

No one was really curious to try it 😉

Let’s see if they ever fix the problems on the BIOS.

 

[Hans]

yes my microphone works. It is located at the bottom right corner. There is a small groove in the case.  If I open the Windows mixer for recording device, I can see a Intel SST microphone and the mic level.

I tried recording with Audacity, it works without a problem.

[Hans]

I took some photos from the outside and also opened the tablet. I wanted to search if it possible to connect power somewhere inside. Sadly it is not easy to figure out, there are no obvious test points. Somehow I would need to fiddle around at the USB-C connector.

The mainboard looks to be glued onto the screen. There are two screws, but they seem to offer some support for the connector. There are pins for a second speaker. Around the Realtek sound chip there is place for a few other ribbon cable connectors, I don’t know what they are for. Next to micro SD slot there seems to be an unpopulated slot and an area around it. I think this could be a place for a SIM card plus mobile data modem. The R+ R- pads have no connections, there is no component to attached to it.

At the top there is one WIFI antenna and two unused mounting spaces. One could be for example for an ambient light sensor. If Chuwi would relocate the speaker e.g. to the top or the other side, I would be possible to have a bigger battery inside.

I would love to see what is under the cans, but I don’t want to risk damaging it. The smaller contains the WIFI chip, the antenna is going there. The bigger one must be the CPU + some interface chips + eMMC.

If someone wants to donate me their faulty one, I can do a full teardown and post high-res photos.

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[Hans]

where is the BIOS chip located? Is it under the cans? Then it is much harder to figure out. See my thread + pictures here: http://techtablets.com/forum/topic/review-of-hi8-pro-after-several-days-usage/

 

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