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[on:]

Hello,

I'm fairly new to the Arduino and electronic projects in general, I figured this would be the best place to ask. I have a small project i am working on at home and would like to know what sensor would be best to measure distance below 10" inches (25.4cm). I have narrowed some searches down to a Hall effect sensor or an ultrasonic sensor. Hall Effect would the the prime choice for my application, but how strong of a magnet would i need? Is this even the right approach?

Thanks!

[Reply #1 on:]

what is the precission you need  0.1  or 0.5 or 1 cm?

check this thread - http://arduino.cc/forum/index.php/topic,106043.0.html -

[Reply #2 on:]

Cool! ill check out that thread

The precision should be roughly 0.1 cm, or even 1/16th of an inch would do. In my original post i said it needed to be under a 10 inch distance. However, it looks as though i can use it under a 6 inch distance just fine.

[Reply #3 on:]

When you say you would like it precise to .1cm, did you mean that you want it accurate to .1cm? Precision means repeatability, and accuracy means quality of measurement. It's highly improbable to get either with an affordable ultrasonic sensor. What is your application? If we know that then we can better help to determine the right approach.

[Reply #4 on:]

After reading this thread, I would suggest this:
http://arduino.cc/forum/index.php/topic,106043.0.html
I haven't tried it yet, but this library should work with the Maxbotix line of sensors when in PWM mode and wired the same way as the HC SR04, SRF05, and SRF06.

[Reply #5 on:]

The precision should be roughly 0.1 cm, or even 1/16th of an inch would do. In my original post i said it needed to be under a 10 inch distance. However, it looks as though i can use it under a 6 inch distance just fine.

How often do you make these measurements?

What is the minimum distance to be measured? also 1 millimeter?

I was thinkin about a linear actuator with a pressure sensor on top... linear actuators can be positioned very precise.