xs1-usb low cost board

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pasau
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xs1-usb low cost board

Post by pasau »

Hi, i have a xk-1a, and i know there is the start kit out there for the xs1-L series. I was wondering if there was something that exists in the same price range for the xs1-u chips. Since they come only in BGA the only options are buying the USB-audio boards that come with the xs1-u chip like the dj-kit or to make a custom board with the BGA, both options being either cost and/or time consuming. I was wondering if there is something similar like the xk-1a either from xmos or partners that only has the most basic stuff and makes the cost cheap like the xk-1a (50-100$) or even cheaper like the startkit if you just want the microcontroller. I guess the next best option is to make a usb PHY board that is compatible with the xk-1a, but i would like to use the xs1-u integrated PHY. Thank you!


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Folknology
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Post by Folknology »

Ironically the Startkit is based on a U series device, however the usb tile is dedicated to debugging functions for the kit. This has also been discussed before, some things are possible by jumping through firey hoops.

regards
Al
pasau
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Post by pasau »

yeah, i have tried loading my code on a xtag2. i managed to load the code sample but i could never make my own build work. Or perhaps i did but i never worked as i intended, even for something simple like toggling a port on the XSYS connector. In the end i think i ended up breaking my xtag2, now it wont load some binaries on other boards anymore, and its ID number changed to something weird like HC__12 from something normal like q829gk3

In any case, i am searching for the easiest option for a USB interface with bulk transfer or CDC class, which already has drivers and a firmware example. What i want to do is data streaming (not audio). I found the VCOM example on sc_usb on github and that seems like what i need. I found out it only compiles with the tools version 11, as they are the only tools that can compile this old XUD version correctly in a build. Furthermore, i managed to migrate and compile the build for the newer XUD (the one which supports XS1-USB) by making required changes to API calls.

Now it is all about finding the hardware in the simplest way. A XS1-USB chip isnt even a priority anymore. I would like to refrain from buying something like a whole USB-audio platform and if possible from making a PCB that involves the whole thing.

Thats why i considered making an extension module for my XK-1A using IO extensions that would have a USB3318 PHY or similar. But it doesn't seem like a great idea since according to the usb design files, this ULPI PHY requires more regular IO's than i have on one header. It also requires a reliable 13Mhz clock for the USB specification which comes from a clock port and not an IO port. Finally i am not so sure about the XUD being flexible enough to remap its ports on any IO pin on its tile. Has anyone done something similar to that using XK-1A?

Theres the option to use a USB-UART converter, and use the xcore UART stack. It would give me barely enough throughput (max 3Mbps, i need 2.7) for my application. Overall, still seems like a crappy option, as i would like to to real USB.

Finally, i could buy a brand new USB-AUDIO board from XMOS at $300+, which give me way too much stuff just for the basic functionality i am looking for.

Any ideas please? Thank you in advance!
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Folknology
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Post by Folknology »

From USB devkit point of view the USB SliceKit looks good and provides a comprehensive set of expansion features including analogue.

(might be slightly overkill for your needs)

regards
Al
carkifelek
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Post by carkifelek »

pasau, you need a very application specific board, usually people design their own boards when such is the case. However, since you don’t have enough time for hardware development, you’ll have to compromise somewhere. I think USB SliceKit has been correctly identified since it provides all the basic interfaces that you require. Also, the 3mbps limit of the USB to serial convertor is not its limit, it’s actually that of the serial protocol. You can always use a small Ethernet controller for higher transfer speeds.

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