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Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 7:53 pm
by landon
Various demos show ganging XK-1 boards together, but were I to try these sorts of configurations, it appears that I'd have to buy multiple $100 XK-1 dev kits whether I needed the XJTAGs or not.
Is there a source to purchase XK-1 boards individually without XJTAG devices?
Landon
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 8:05 pm
by leon_heller
I don't think there is. You could sell the unwanted XTAGs on Ebay. :D
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 8:23 pm
by landon
Hi Leon,
I'm starting to see the logic in the Sparkfun board and the new minimalist board project - looking forward to their progress.
Landon
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 9:58 pm
by leon_heller
The Sparkfun board has some problems, such as the 1V regulator getting *very* hot. They should have used a switcher.
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 10:10 pm
by landon
Good to know. I haven't fired up my SFE XMOS board yet.
What would have been an appropriate 1V switcher part? I'm considering designing my own board here shortly.
Landon
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Sat Sep 25, 2010 11:45 pm
by leon_heller
I'm using the same one that's on the XK-1 for a board I'm working on.
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Mon Oct 11, 2010 6:22 pm
by landon
I recently fired up a Sparkfun XMOS board and used an IR thermometer to scan the board.
The regulator section looked like it was running 105-115 F. This is the board with the USB interface. I have a couple more coming that have those removed (re: the tx/rx/jtag hardware error). Haven't received them so haven't measured temps on that board yet.
Landon
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Mon Oct 11, 2010 7:17 pm
by bsmithyman
landon wrote:I recently fired up a Sparkfun XMOS board and used an IR thermometer to scan the board.
The regulator section looked like it was running 105-115 F. This is the board with the USB interface. I have a couple more coming that have those removed (re: the tx/rx/jtag hardware error). Haven't received them so haven't measured temps on that board yet.
Landon
Since the FTDI chip doesn't use the 1V rail, I'm guessing it'll be comparable to the version with the interface... It's a shame there are no easy drop-in replacements for that 1V LDO.
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Mon Oct 11, 2010 7:26 pm
by landon
I'm wondering how the heat issue will affect the life-expectancy of the part/board?
Re: Can XK-1 boards be purchased separate of XJTAG?
Posted: Mon Oct 11, 2010 8:01 pm
by bsmithyman
The BD10KA5WF is rated to a 105 C operating temperature on the datasheet, which is 221 degrees Fahrenheit, vs. the measured 105-115. They've also got a document that says it stands up to -85 C to 150 C cycling when not in operation (
http://www.rohm.com/products/lsi/power/ ... bd10ka5wf/). Sparkfun uses lead-free solder paste, so that's got a very high melting point as well (though even standard solder needs something > 200 C to start softening). I think it's probably fine from a mechanical point of view, but it's a lot of wasted power for anything run from batteries.