View Single Post
  #1   Spotlight this post!  
Unread 10-03-2010, 00:06
Kevin Sevcik's Avatar
Kevin Sevcik Kevin Sevcik is online now
(Insert witty comment here)
FRC #0057 (The Leopards)
Team Role: Mentor
 
Join Date: Jun 2001
Rookie Year: 1998
Location: Houston, Texas
Posts: 3,721
Kevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond repute
Send a message via AIM to Kevin Sevcik Send a message via Yahoo to Kevin Sevcik
Re: Measuring resistance using analog breakout

Easiest to wire would be a voltage divider between a known resistance and your sensor. Think of it like your potentiometer, only with a variable resistance between +5 and GND.

Wiring would be so:
Sensor between SIG and GND
Known resistor between +5V and SIG

You'd get a varying voltage on your SIG equal to the following:
R - constant known resistance
r - variable sensor resistance

V = 5 * r / (r + R)

If you pick an R value about 5-10 times the maximum value of r, you'll end up with a moderately linear signal, if rather small.

Other options are various amplifier and/or transistor circuits which will all be a bit complicated.
__________________
The difficult we do today; the impossible we do tomorrow. Miracles by appointment only.

Lone Star Regional Troubleshooter
Reply With Quote