disconnecting from the LPC link

[lpcware]

Content originally posted in LPCWare by dragilla on Thu Nov 17 03:52:38 MST 2011
Hey, I have a lpcxpresso board with a lpc1769 cpu. I want to disconnect the debugging part to test my program outside the lab.
Is it enough to supply 3v3 and gnd to the pins that the debugger connects to?
That's it?
I see there is a 12 oscillator on the lpc link board and I see none on the target board... or maybe the two rectangle pieces with 12.00 and 25.00 are oscillators... does that imply something? :)
In other words, do I need anything else except the power supply to make the board work without the lpc link?

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Thu Nov 17 10:35:03 MST 2011

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Quote:

How short is your "short"? :)

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[INDENT]short: 1.5m

long: 5m

float: 15m[/INDENT]

[lpcware]

Content originally posted in LPCWare by dragilla on Thu Nov 17 10:20:23 MST 2011
How short is your "short"? :)

edit: anyways, it works with my 1.5 m cable :)
Thanks.

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Thu Nov 17 09:42:08 MST 2011
This LPCXpresso1769 LPC-Link (yes, LPC-Links are different :eek:) power regulator CAT6219 is able to supply 500mA. That's everything your USB2.0 should deliver :)

LPC-link, 1769 and Ethernet PHY also need a lot of power but there should left enough for GPS. My 80mA GPS is working without problems.
With LPC-Link connected my PC is delivering 250mA (320 mA while flashing / debugging) for the complete board :eek:

Of course that's only working with short USB cables :mad:

[lpcware]

Content originally posted in LPCWare by dragilla on Thu Nov 17 08:04:58 MST 2011
So LPC-link uses SWD, and 4 pins is enough: Reset, SWCLK, SWDIO, GND.
Thank you very much :)

Another one: how much power can I safely drain from the 3v3-out when the board is still in one piece (usb-powered)? I guess the limitation here is the voltage regulator (5 to 3v3) but I don't know how much the target board itself uses...
I have already connected the 3v3-out to my imu 6deg board. Now I wanted to connect my gps, but this one uses 100mA, so I'm affraid a bit :)

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Thu Nov 17 07:32:49 MST 2011
Yes :)

See #9 of http://knowledgebase.nxp.com/showthread.php?p=8311

[lpcware]

Content originally posted in LPCWare by dragilla on Thu Nov 17 07:25:36 MST 2011
OK. Thanks. If I only used the word splitting in search :)

Another question: When the boards are apart and I connect the target board to an external power supply can I still connect it to the lpc link (connect all the pins except 3v3x)?

regards,

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Thu Nov 17 04:17:40 MST 2011

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Quote: dragilla
In other words, do I need anything else except the power supply to make the board work without the lpc link?

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No :)

See: http://knowledgebase.nxp.com/showthread.php?t=1865

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Quote:

...two rectangle pieces...

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...and the round pieces also are described here:

http://www.embeddedartists.com/sites/default/files/docs/schematics/LPCXpressoLPC1768revA.pdf