Help needed - USB Type-C to Type-C On-The-Go (OTG)

[Jorj]

This forum seems to be loaded up with folks that know infinitely more about electronic circuits than I do, so I'm throwing myself on the tender mercies of the community to see if anyone can help me with this.

I grabbed up on of those cheap Sabaj DA3 DACs for fun, and took a look at the included cable, which is USB Type-A (host) to Type-C (slave). Not really helpful from my Samsung Note 8, which is Type-C. Now, I know that I could bodge together a gross-looking assortment of adapters and cables to get the connection to happen, but I don't wanna. The DA3 is Type-C in, and the phone is Type-C out. Do you think I can find a Type-C to Type-C OTG cable anywhere? I've been looking and struck out.

In the past, it was easy enough to make a directional OTG USB cable by jumping the normally-floated sense pin to the ground pin. With Type-C, things are different. There are a lot more pins, more densely packed, and the connections are reversible, but that does not mean they are the same on both sides. Also, I have been looking for a pinout guide on the off chance that I could DIY one, but the documentation I can find does not mention how to make one of the ends act as the host.

Anyone here have a suggestion that is not to bodge several adapters together?

 

[dc655321]

I'm probably revealing my own ignorance here, but I would have thought you could get by with a usb-c to usb-c cable here?
Perhaps subject to the caveat that your Note 8 supports OTG?

 

[Jorj]

I'm probably revealing my own ignorance here, but I would have thought you could get by with a usb-c to usb-c cable here?
Perhaps subject to the caveat that your Note 8 supports OTG?

I think you may be correct. I pulled the latest revisions of the USB Specifications, and glanced over the OTG addendum. No mention of Type-C. So I pulled the Type-C specification, no mention of OTG. It would appear that (possibly) USB Type-C does not require any resistor or jumper trickery at the cable level to initiate a Host\Peripheral connection.

I guess there is one way to find out for sure!

 

[dc655321]

It would appear that (possibly) USB Type-C does not require any resistor or jumper trickery at the cable level to initiate a Host\Peripheral connection.

That was my understanding, or possible misunderstanding.
Good luck! Let us know how the experiment fares.

 

[Jorj]

Well, I must admit, I knew that USB Type-C was a different critter, but I was simply blown over by how little I knew about the standard and its history. I read the official specification documents and the actually quite good Wikipedia summary, and it was an eye-opener.

Suffice it to say, USB Type-C, v3.1, Gen 2 is a VERY capable format. 18 conductors. Shielded, with another 4 twisted+shielded pairs inside the outer shield. A eMarker chip in the plugs with Mfr info, latency info, etc. This is in contrast to non-Type-C, with only four conductors, or Type-C v2.0, which only requires six.

OTG has been replaced by the DRD protocol, which does not depend on the cable at all (except that it needs to be the latest generation). Host and peripheral negotiate to determine power distribution and which will be which. Impressive, but massively fractured, confusing and the standards body is doing a less-than-stellar job of educating the public at large. Still so much confusion about versions, power capacity, things like the proprietary Thunderbolt protocol (which uses latest gen Type-C).

If you ever want to tear your hair out, just go to Amazon and do a search for Type-C cables. Yikes.

 

[Blumlein 88]

I have a phone with type C. Yes cables will drive you mad. You almost need detailed knowledge of what's on reach end to get things working right. The standards which aren't fully agreed to btw yet are so loosely adhered to they are mostly useless.

 

[Timbo2]

I have a the same DAC and an Android based Essential PH-1 which also uses Type C.

Works fine with a Type C to Type C cable for me. The spec is bidirectional.

Off topic - the DAC draws quite a bit of current compared to the stock Essential USB DAC. If you really want to watch it burn through your phone battery kick the up-sampling to DSD 512.