Arduino Ohm Meter

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hi everyone! found link http://evilquark.com/blog/?p=49 arduino ohm meter , purchased first arduino because of it.  i tried out , have few questions.

1.  why 10k resistor (or known resistor) have attached ground instead of 5v circuit work? using 1k resistor "unknown resistor"

2. if wanted test multiple unknown resistors @ once (like 5 unknown resistors) , display information, how go it?

sorry noob questions.  im real new @ interested in learning arduino more.  thanks!

hi,

1. make voltage divider - http://en.wikipedia.org/wiki/voltage_divider

there +5v --- [ unknown ] ----*----[ 10 k ] --- gnd

now know @ * there voltage between 0 , 5v

if remove 10k * cannot between 2 values become + 5v

this possible: gnd  --- [ unknown ] ----*----[ 10 k ] --- +5v
the sw formula different



2. easiest way: have replicate schematics 5 times. arduino has 6 analog lines, can done. aware have small delay between analog reads.

"there exist no stupid questions, stupid answers", free after confusius


Arduino Forum > Forum 2005-2010 (read only) > Software > Syntax & Programs > Arduino Ohm Meter


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