Hi,
I have the pin-out of the expansion header, but couldn’t find the documentation for the pins in the header, i.e. max speed, io-levels etc.
Also, would it be possible to add support for TDM8 and TDM16?
Thx David
1 Like
Hi @audio-dav, the pinout is listed at the link below. That covers the pin names and nominal voltages and currents you might expect from the supply. In most cases, you’d go to an isolator and on the other side of the isolator use whatever voltage you want. See the picture in the wiki link.
Right now, the choices are 16 or 32-bit words and its fixed at 48K. There’s more programmability that could be had here, but we’d need someone to champion it and verify it. Ideally someone would have a new piece of hardware they need to get working (that the QA403 will be testing in manufacturing) and that’s a good way to get the support added and verified. I think the hardware (LPC55S16) can do the TDM. You might take a look through the LPC55S16 spec and see what it can do, and we could probably add that it. For example, for TDM I think we could add a way to specify a slot, but I don’t think we could add a way to have, say, 8 independent channels of data over a TDM8 packet.
What are you thinking?
1 Like
thanks for the link matt,
LPC55x can do TDM and it’s possible to run 8ch per data pin.
no stress to implement this, we played with the idea and might need it to feed a board that has an 8ch (ESS) DAC that would be nice to feed directly via TDM, 1-2 channels at the time to avoid the need for relay boxes or i2s muxes.
Hi @matt Thanks for the reference. I am using PyQa40x repo for using QA403. I want to use front panel I2S interface for DUT. How to enable I2S interface from PyQa40x? Are there any registers to enable I2S? Using QA40x app I was able to verify clocks and data from expansion connector. Any help will be appreciated
Hi @scp, currently there are not any ways to change the I2S params via REST
Hi @matt Thanks for your reply. Actually I wanted to know whether I2S can be enabled using PyQA40x libs
I found REST API to do so:
But since my usecase was to load .wav file into the dac buffer and play waveform via FP I2S pins to DUT and capture ADC buffer together.
Hi @matt,
maybe you have already seen the thread about Phonalyser.
User asks if it possible to implement access to I2S extension port in my app. But there is no open information about USB protocol for I2S control.
Can I ask if you can provide such information, so I can implement this functionality in my app?
And another question: I have see somewhere, that under some condition also 384k sample rate is possible. But I have not found any open information about it.
Thank you in advance and
Best regards,
Dimitrij
1 Like
Hi @dgo42,
The front panel I2S will play whatever the analyzer DAC is playing on the QA403. When you click the I2S button the QA403 app, that behavior is toggled. I’m not sure if the baremetal code shows how to do that or not, but I could probably get the register write used if need, or you could sniff it on a USB analyzer.
1 Like
Hi @matt ,
I have already used SW simulator, what @raph29 has wrote and extended my own HW simulator, I made early.
Currently both QA40x genuine software and my Phonalyser works with HW simulator.
After I release next version - user will test it with real hardware.
Current version 1.1.0 already works well with QA403!
1 Like