Using helix as a USB interface with Android....help pls

[wilso2510]

Hi was wondering if anyone can help? I'm trying to use various DAW's in Android which all recognise the helix as a USB audio device, the problem is when I arm the track I'm getting no input signal from the helix. I've used various devices with a few different DAW's and the same thing happens which leads me to think I'm doing something wrong with the helix? Is it not just plug and play? Any help would be greatly appreciated.

[brue58ski]

I'm almost positive there is NO android capability at this time. In order for the Helix to work on any platform it's gonna need drivers. There are no Helix/Android drivers

[mdmayfield]

Android can probably see the Helix since its audio interface component is USB Class Compliant. My educated guess as to why it's not working on Android is that Helix uses a more advanced / less common part of the USB audio class standard which Android doesn't implement at this time.

[brue58ski]

Android can probably see the Helix since its audio interface component is USB Class Compliant. My educated guess as to why it's not working on Android is that Helix uses a more advanced / less common part of the USB audio class standard which Android doesn't implement at this time.

 

Don't you still need a driver?

[mdmayfield]

Don't you still need a driver?

 

 

Yes, but only on OSes that don't already have a built-in driver for USB Class Compliant audio devices. For example, you don't need a driver for the Helix on macOS or Linux, because those have USB CC audio support built in, but you do need one on Windows.

 

Last I saw, Android has some limited support for USB CC audio, but not very extensive. AFAICT that seems consistent with the idea that Android can *see* the Helix but can't actually *use* it, because of the limited built-in driver.

[wilso2510]

Ah that would make sense then. It was just going to be a quick way to get ideas down on my phone. Thanks for the help.

[Rewolf48]

I tried this yesterday - I downloaded soundcamp onto my Galaxy S5Neo and got an OTC cable. When it was all plugged together the phone could definitely see Helix and Soundcamp / Samsung Professional Audio was grabbing exclusive access to the USB Audio device. But no sound output via USB, instead it used the built in speaker. When I unplugged the cable it actually said USB microphone unplugged, nothing about a speaker, which is consistent with what it was doing.

I did a bit of digging around, and while not Professional Audio specific I did discover that the USB audio built into Android 5.1 onwards has the following spec:

Android 5.0 (API level 21) and above supports a subset of USB audio class 1 (UAC1) features:

The Android device must act as host
The audio format must be PCM (interface type I)
The bit depth must be 16-bits, 24-bits, or 32-bits where 24 bits of useful audio data are left-justified within the most significant bits of the 32-bit word
The sample rate must be either 48, 44.1, 32, 24, 22.05, 16, 12, 11.025, or 8 kHz
The channel count must be 1 (mono) or 2 (stereo)
And further below:
Typical USB host mode audio applications include:
music listening
telephony
instant messaging and voice chat
recording
For all of these applications, Android detects a compatible USB digital audio peripheral, and automatically routes audio playback and capture appropriately, based on the audio policy rules. Stereo content is played on the first two channels of the peripheral.
There are no APIs specific to USB digital audio. For advanced usage, the automatic routing may interfere with applications that are USB-aware.

 

The problem I believe is that Android USB audio is intended for simple USB speakers - mono or stereo; it can't cope with Helix 8 channel output, and despite the description it doesn't do the decent thing and just restrict itself to USB 1 & 2 - you get nothing at all.

I will keep plugging at it - I only want to be to trigger samples using Helix pedals (like Alex Lifeson does) for intros and special effects, but at the moment it has to be my laptop.