I have dowloaded the original XMOS Software and it looks like it should be quite easy to send some messages to the I2C bus depending on the format a sample rate. But adding some more complex library to draw nice and smooth numbers and text on some graphical display would probably be more difficult for a XMOS-beginner like me. Anyway, we would need the Khadas modifications of the XMOS software, and if I understand the XMOS licence correctly, they are NOT allowed to publish the whole XMOS Code themselves in source code - it is not really fully “open source” in this sense, they can only distribute the compiled “object code”. But maybe they would be allowed to publish a “patch” (diffs) containing the modifications of the original software???
Actually, I do not have the TB yet. I just wanted to get one, but I think now it might be worth waiting for the “next generation” if it really(?) comes in a few months…? I could hope for some improvements of the extensibility…
To be honest: the extension connectors on the board are not really beginner-friendly, and the OLED and I2S connectors are nothing but “unfriendly” extensions of the much more friendly GPIO pins of the VIM/Edge. And Khadas does not offer any accessories for the TB itself, so they are pretty useless at the moment. They probably also expect that the VIM/Edge will be used to drive an OLED display and other extensions (still: I do not see any use of the additional I2S extension… to connect another DAC to the VIM/Edge? why another??)
Personally, I would rather avoid stacking the boards and connect just the power and USB pins and use the other GPIO pins directly from the VIM/Edge board - if I actually wanted to use the TB with a VIM/Edge, which is not what I plan to do at the moment. Instead, I would rather use the board as a standalone DAC (anyway, it is already an USB DAC with its own XMOS processor, not just a simple “dumb” I2S DAC!) - so I would like it to be capable of driving its own display and possibly having its own volume control for use with headphones, just like the AUDIOPHONICS board (which is, paradoxically, “just” an I2S DAC!). But that means to be able to modify the firmware according to the displays/extensions used.
So, we would need to get Khadas’ modifications to the original software and in the best case also some more friendly extension connector, at least.