Reuse of MISO (X0D00)

Technical discussions around xCORE processors (e.g. General Purpose (L/G), xCORE-USB, xCORE-Analog, xCORE-XA).
jmag99
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Reuse of MISO (X0D00)

Postby jmag99 » Wed Nov 05, 2014 10:31 pm

I am attempting to re-use the MISO pin on a XS1-U8A-64. I am using as an I2C SCL pin with a 10K pull-up on it. When I drive the line low, it only gets to 2V. I measured with a meter that the line has 10K to 3.3V. It appears to be open to GND. I am using the I2C_Simple module. Any idea why this might be?
jmag99
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Postby jmag99 » Wed Nov 05, 2014 10:55 pm

Also, I should add that SDA goes low properly and is on one of the other SPI lines (reused after bootup). This line also has a 10K resistor. I am trying to determine what is different.
stdefeber
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Postby stdefeber » Thu Nov 06, 2014 7:21 am

Did you check the specific port properties ?
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Ross
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Postby Ross » Thu Nov 06, 2014 11:48 am

Is the SPI device driving against it? (is SS high?)
jmag99
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Joined: Tue Jul 20, 2010 9:45 pm

Postby jmag99 » Thu Nov 06, 2014 12:56 pm

Thanks, that was it. I assumed it would be left as an input with the pull-up causing it to keep SS high, but that was not the case for some reason.

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