On Aug 3, 2024, at 10:33?AM, david mugridge <dave@...> wrote:

?

I’m interested in digital modes and want to use the T41's usb interface for audio. However the standard Audio Library only supports usb-audio for the default 44,100 Hz sample rate. Unfortunately since the T41 code increases the sample rate to 192kHz (via the call to SetI2SFreq()) this breaks the usb-audio - any audio received or transmitted at this sample rate is severely distorted.

I’ve been working on source-code changes to the Audio Library (7x Teensyduino source files changed), and now have 192kHz usb-audio working on my Windows pc. With quick hacks to the T41 code I have also confirmed that the radio works for both receive and transmit with wsjt-x. (the T41 code would need extra work to integrate usb-audio properly, including CAT support).

?

The patch requires Teensyduino Version 1.59 and either Arduino 1.8.19 or Arduino 2.3.2.

I’m wondering whether there is sufficient interest in my Audio Library patch, and if so, whether a small number of “beta tester” volunteers would be willing to further test it before I make the patch and installation instructions generally available. Ideally the volunteers would have good programming and fault diagnosis skills (in case things go wrong), a Teensy 4.1 with an Audio Shield fitted, and an oscilloscope to confirm the correct waveforms . It would be great if one or more volunteers can test it on linux (both the development environment and as a linux audio host).

?

Volunteers please contact me direct. All feedback welcome.

?

Rgds,

Dave Mugridge M0JTS

?

?

?

?