Khadas tone board and Pixel 2 XL with powered USB hub?

[motorider]

Is this the hub? https://www.amazon.com/dp/B01IDI9YFW/ref=cm_sw_em_r_mt_dp_U_qvmpCb8GWEET3

The phone must be connected to the USB-IN port and it should not charge from that port. You say the hub powers up the phone which makes me think you're connecting the phone to one of the 7 device ports. The phone must be the "host" in this case and connected to the USB-IN port, USB is not symmetric - one side is host (phone) and the other is device (DAC). You most likely need to use an OTG adapter, you definitely have to use one with the standard USB phone connector but things may have changed with USB-C - not sure. Also the phone may not detect the DAC automatically, on my phone I have to pull down the quick menu and select "Detect USB device" from there.

As a side not it is odd that hub doesn't appear to use a USB type B connector for the host uplink.

Well I tried that. No go. In fact I can't get my Droid turbo 2 to work either.

 

[gvl]

Well I tried that. No go. In fact I can't get my Droid turbo 2 to work either.

Are you using an OTG adapter?

 

[motorider]

Are you using an OTG adapter?

Don't think it matters since I am powering the hub via power outlet. I'm not worried about charging the phone. Maybe I'm misunderstanding the OTG cable

 

[gvl]

Maybe you are. Basically you want this:

Phone -> OTG adapter/USB cable -> USB in on HUB -> Khadas

Seems the Pixel comes with a USB-C to USB-A adapter which is basically the OTG, try it.

 

[motorider]

Maybe you are. Basically you want this:

Phone -> OTG adapter/USB cable -> USB in on HUB -> Khadas

Seems the Pixel comes with a USB-C to USB-A adapter which is basically the OTG, try it.

I'll try it. I have a usbc to usba cable that should work. We will see. Thanks for the input.

 

[gvl]

I'll try it. I have a usbc to usba cable that should work. We will see. Thanks for the input.

The OTG cable is a special cable that makes the phone to think it is the "host" which is necessary for the USB audio to work. When connected with a normal cable the phone thinks it is a "device", like a flash drive or a MTP, so without OTG it is like connecting a flash drive to your DAC, not very exciting.

 

[MKreroo]

The OTG cable is a special cable that makes the phone to think it is the "host" which is necessary for the USB audio to work. When connected with a normal cable the phone thinks it is a "device", like a flash drive or a MTP, so without OTG it is like connecting a flash drive to your DAC, not very exciting.

Hey, sorry for digging up old post. Was trying to solve similar problem, in that I want to also power the DAC with my phone (s9+, 500ma should be fine).
I want to know if a USB c to c cable is possible (quite confused about the OTG stuff, I understand the idea and whatnot, just not about if type C has this function as well)

Thanks!

 

[gvl]

https://www.amazon.com/dp/B072V9CNTK/ref=cm_sw_r_apa_i_vEvYEbEFBMGDN

 

[MKreroo]

https://www.amazon.com/dp/B072V9CNTK/ref=cm_sw_r_apa_i_vEvYEbEFBMGDN

thanks for the link, I do have an OTG adapter.
so a C to C connection is not possible with the TB due to devices not being able to identify itself as a host bc the lack of OTG?
I thought type C doesn't need OTG

 

[gvl]

Good question and I have been wondering myself and couldn't find a definitive answer. In theory USB 3.0 introduced a protocol for the endpoints to auto-negotiate host/device roles, but is it guaranteed to be implemented on all devices? OTG has been around and most devices support it. Sounds like you can't get it to work w/out an OTG adapter?

 

[MKreroo]

Good question and I have been wondering myself and couldn't find a definitive answer. In theory USB 3.0 introduced a protocol for the endpoints to auto-negotiate host/device roles, but is it guaranteed to be implemented on all devices? OTG has been around and most devices support it. Sounds like you can't get it to work w/out an OTG adapter?

Indeed, any type c to c cables that I own failed to work, on both laptop and phone. Type A to c works as expected though.

The stock OTG did work, just that the c port doesn't fit with my case....

As far as I know, S9/+ does support USB host mode so I suppose it be able to do OTG as well (though then it's weird that they provide an OTG adapter)

 

[gvl]

All OTG does is a hardwire host mode selection.