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Reclaiming D4

Posted: Sat Mar 30, 2013 10:01 am
by enno
I see that the D4 pin being used as the CS for the uSD interface has a 2k2 pulldown resistor along with a 1k current limiting resistor.

My problem was I was moving some code from the Uno/Ethernet shield environment to the Ether10 and had been using D4. The device I'm connected to is open collector and wants me to pull the line high so it can then pull it down. The uSD resistors interfere with this of course. I had hoped there might be a jumper that would allow me to disconnect the uSD, or maybe a link I can cut somewhere to achieve the same thing. No biggie if there's not (I changed my code), but maybe this is something a future rev of the board can offer?

Re: Reclaiming D4

Posted: Sun Mar 31, 2013 5:07 am
by cef
FWIW: This is also true of D11 (used for DI on the uSD), and D13 (used as SCK on the uSD).

I'll pass along the suggestion to Jon & Marc and see what they say.

Re: Reclaiming D4

Posted: Sun Mar 31, 2013 8:49 am
by enno
cef wrote:FWIW: This is also true of D11 (used for DI on the uSD), and D13 (used as SCK on the uSD).
True enough... although I doubt anyone is buying an Ether10 and not expecting to use the Ethernet, which shares the SPI lines you mention. :-)