Sending data from a PC to an XTAG-2

[tomcarter259]

I have a board with an XS1-L1 processor connected to a PC through an XTAG-2. What I would like to do is have a (java) program running on the PC which can send information to the program running on the XS1-L1.

Previously I did this with an XC-1A development board. This has an FTDI based usb connection and so I was able to connect to it as a serial port and then send the data using UART.

XTAG-2 does not provide a COM port to connect to and, as far as I can tell, can only be accessed by the XMOS tools.

Posts such as these ones seem to suggest that you can only use it through the XMOS tools, but imply that might change.

http://www.xmos.com/discuss/viewtopic.p ... 55&start=0
https://xcore.com/forum/viewtopic.php?f=8&t=1421
http://www.xcore.com/forum/viewtopic.ph ... 95&start=0

Is this still the case? Is there any way I can send data to the boards from a program running on the PC?

Thanks

[rp181]

I have also always wanted to do similar communication. However, nothing is officially released yet to access a virtual COM port from the XTAG. I recommend either
1) Using a spare dev-kit (e.g. XC-1A) to simply relay the serial stream to usb or
2) (preferred) use an external converter, such as:
http://www.sparkfun.com/products/718
I would go with ftdi chip based converters (i've had the best driver experience with them).

[segher]

You really, really, really, really do not want to use a UART for reliable
communication, esp. programmed. Use something simple instead
on those I/O pins; or go for luxury and connect an xlink to the XTAG2.

UARTs are great if you want stuff to work 99% of the time.

[rp181]

What do you mean "simple"? Do you mean other protocols such as SPI? Generally, all my needs are streaming data, so the dropped data from UART isn't an issue. Depends on the application - for me, UART is often the simplest to use to interface with a host PC.

[tomcarter259]

I can connect an xlink to the XTAG2 but then I still can't access the connection from the PC.

It seems that I am going to have to use a different connection to XTAG2. The best options seem to be either a USB to UART or SPI convertor as rp181 suggested, or maybe even creating an ethernet MII.

[tomcarter259]

A followup:

I spoke to Ali Dixon from XMOS today. There is definitely no way of sending data from the PC to an XMOS processor via an XTAG2 at present. They are planning on opening it up so that you can send data across if you have connected an xlink to the XTAG2, but this hasn't been implemented yet.

For now I am going to attach a USB to UART converter. You can get them inbuilt into USB cables such as this one:

http://www.virtualvillage.co.uk/usb-to- ... pping_feed

Hopefully it won't be too long before the XTAG2 is opened up...