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Author Topic: gyroscope L3G4200D  (Read 1173 times)
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please if any one can help me understanding the DR and BW and Filers( HPF , LPF ) and what cutoff frequency mean
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DR?  Where is that mentioned?  Data rate perhaps?

BW = bandwidth, for a low-pass filter its roughly the frequency at which the output has dropped 3dB (power has halved) and usually about the same as the breakpoint frequency.  Technically its the bandwidth of an ideal "brick-wall" filter than passes the same noise-power.  The cutoff frequency is really the same thing for a _low_ pass filter.

The device has configurable digital filters that are setup via I2C or SPI interface.  Don't turn on the high-pass filter unless you have good reason, it'll prevent proper integration of the output.  Depending on how often you want to sample the output you can set low pass filtering to average out the noise.
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> please if any one can help me understanding the DR

I think that might be the Device Ready (DRDY) pin.

> and BW and Filers( HPF , LPF ) and what cutoff frequency mean

HP Filter:  High Pass Filter.  Frequencies below the cutoff frequency are attenuated by 50% or more.
LP Filter:  Low pass Filter.    Frequencies above the cutoff frequency are attenuated by 50% or more.

If that doesn't help you probably need to be more specific.
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If you read the datasheet more carefully, it's all there.

DR = Data Rate : two bits for the output data rate in the CTRL_REG1 for 100/200/400/800Hz
BW = Band With : two bits for the Bandwidth selection in the CTRL_REG1. See the table for the Cut-Off.
How this Cut-Off is actually used, is not very clear in the datasheet.
It is used in combination with the filters.
HPF = High Pass Filter. Higher frequencies are passed. Slow motion is filtered out.
LPF = Low Pass Filter. Higher frequencies are blocked, to reduce noisy or jumpy results.

What the best settings are, is hard to tell. You might look for a good example and use that.
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