ADAT Multichannel In / Out?

S

syso

Member
Is anyone already working on ADAT Multichannel In and Out? I wondered if it would be a quick way to give
me 2x8 In, 2x8 Out (2x TX, 2x RX) via my ADAT-Interface.
 
PaulStoffregen said:
ADAT (or SPDIF) input is unlikely to ever happen on Teensy 3.x. The hardware support just isn't there. But future Teensy boards (2019, maybe mid-to-late 2018) are likely to have the needed hardware.
Click to expand...

It doesn’t look like this has been done yet, but I’m guessing it is feasible on Teensy 4.0?
 
rasmus_b said:
Why shouldn't ADAT work on 4.0 if it works on 3.6?
Click to expand...

Clock generation on Teensy 4.0 is very different from Teensy 3.x. Pin muxes also have small but important differences. Audio I/O code written for Teensy 3.6 can't just automatically work on Teensy 4.0. It needs to be ported, to deal with these hardware differences.

For ADAT support to happen, these 3 things need to come together in the same person.

1: Programming experience with the hardware
2: Access to ADAT hardware
3: Willing to invest time into supporting ADAT

Most of the low-level audio I/O code is written by me and Frank B. I know I don't have any ADAT gear. I'm pretty sure Frank doesn't either. Even if I had ADAT hardware here, right now so many other things (like USB audio, OctoWS2811, Quad I2S with BCLK/LRCLK=64, etc) are much higher priority for me than ADAT.
 
ADAT is not working for me! I have Teensy 3.6, with or without Sgtl5000 Board it doesnt work. I try SPIF, its working. Do i need to change something in hardware or software? I try to choose clock source optic or try to clock from my Soundcard with all possible sampling rate, it only produce a digital noise on the first adat channel.
 
I found something; Teensy 3.6 without audioboard(i think there is no way to use together) when i change CPU setting from 180 to 168 MHz it works. There are some audio glitches with my sound interface clock (RME Fireface UC) but if i choose clock from adat(teensy)it works fine with 8 channel. So damm good!
 
Now that radias is not with me anymore, I'll do my best to finish his work. Still I have to make my way through his docs.
The "newADAT" will have a 8x8 switchboard, mixdown and resampler to match standard data rates and selectable output format like ADAT, S/PDIF, AES
The next step will be input other than S/PDIF. But this will take some time. Still I have other to take care of.
 
serhatsoyyigit said:
ADAT is not working for me! I have Teensy 3.6...
Click to expand...
This is because the original ADAT on T3.6transmits at an unstable rate about 44135 samples/sec, which is not a standard in the ADAT world.
This may work with some device, but most times will not. Most ADAT works with 48k and this is the real minimum standard.
 
The CoolAudio chips are definitely the way to go.

I believe the ADAT timing issues have been resolved on the T4 - which has an exact 44100 clock frequency. So ADAT output will probably sync nicely.

ADAT input is really complex with the NRZ being difficult to decode, even with an interrupt driven shift register. The V1402 takes most of the pain away.

Keen to hear how you go, as I have some ADAT gear which has been sitting idle and could be brought back into use.
 
This project uses the CoolAudio chips. I came across this the other day and I think it might be helpful for this discussion. Might be easy to interface the FreeDSP expansion header (I2S) with the Teensy. Although I don't know how clocks are handled.

https://github.com/freeDSP/freeDSPx-ADAT-IO-x4

ADAT-IO-x4.jpg
 
You must log in or register to reply here.
Back
Top