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Author Topic: why are A0 & A1 always high even when i have nothing connected?  (Read 721 times)
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i'm useing an ethernet shield SD on a arduino mega 1280... however whenever i have it connected A0 & A1 read high, why is this?
also what is the maximum size the micro SD card can be and still function with the shield?
« Last Edit: March 18, 2011, 08:23:19 am by TECH GEEK » Logged

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Do  a little research on floating pins, its perfectly normal on very high impedance inputs as used on the Arduino. If you want it to read low, you could connect a 10 k resistor between Gnd and the pin you want to read low (whats known as a pull-down resistor).
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i connected  an led from each pin (seperatly) then to ground. the led lit up as if the pins were shorted... are they?
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also i'm using an Arduino brand, version 2 shield
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i guess that makes sense... what about the max size of the sd card?
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http://www.sparkfun.com/products/9026
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