So you get 130 when?Originally Posted by Pesticida
and you get 167 when?
673mV for 2g worth of acceleration is not a lot to measure or play with.
If you're trying to make a speed/distance sensor, I hope you're reading the part as fast as you possibly can and not just a few times a second.
And in your first post, the math is all wrong...
At 3v, the output is 174mV/g. At 5v, you should have 290mV/g, with ZERO g at 2.5v5 Volt Ref,50 Hz Bandwith with 0.1uF.
So, first off, you have to set the thing so it's sitting level, sensing nothing, right at 2.5v, and/or trim the output to read 2.5v using an external means.
Turn it 90 degrees one way in the axis you are measuring, the output should drop 290mV (1g), turn it 90 degrees the other way from the original 'idle' position, the output should rise 290mV (1g).
All wrong...-0.061g*10 Seconds = Speed -0.61 Meters in 10 Seconds
-0.61 * 10 Seconds = Distance 6.1 Meters
1g acceleration = an acceleration of 9.8 meters per second each second
If you measure 1g of acceleration continuously for one second, at the end of that second, your accelerometer will be traveling at 9.8 meters per second, but will have covered only 4.9 meters (assuming a constant rate of acceleration).
Therefore, .061g of acceleration = .5978 meters per second - per second.
At the end of 10 seconds, the speed will be 5.978 meters per second (assuming a constant rate of acceleration), and the object will have moved 2.989 meters (again, assuming a constant rate of acceleration)...
I don't want to say that it's basic math, but if you're playing with PICs, math like this should come easy once you know what to look for.
http://en.wikipedia.org/wiki/Acceleration
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