Accelerometer doesn't produce interrupt for horizontal movement

KEERTHI G

Expert 2610 points

Other Parts Discussed in Thread: MSP430F5438A

Hi ,

I am using MSP430F5438A microcontroller with LIS331DLH accelerometer sensor.

I can read the acceleration values and it produce the interrupt when the acceleration exceed the threshold limit.

I have the below questions.

1) when i move the board horizontally, i don't get any interrupts.

2) A sensor in a steady state on a horizontal surface will measure 0 g in X axis and 0 g in Y axis whereas the Z axis will measure 1 g.

The above line present in accelerometer datasheet. If i set the threshold 500 mg and enable acceleration in three axis, will it produce interrupt? Because z axix has 1g acceleration.

Please clarify this.

Regards,

Keerthi G.

over 10 years ago

0 Clemens Ladisch over 10 years ago

Guru 320720 points

That depends on which axes you have enabled in the INTx_CFG registers. (And this has nothing to do with the MSP430.)

0 KEERTHI G over 10 years ago in reply to Clemens Ladisch

Expert 2610 points

1) I have enabled three axis for high event. (ZH,XH and YH).
But I can't get interrupt for horizontal movement in x and y direction.
What is issue for that? Is this issue or horizontal movement doesn't produce interrupt?

2) In stable condition, z axis always 1g acceleration. I have enabled all axis. So Z axis also enabled. So If I set 500mg threshold, will it produce the interrupt in due to z axis acceleration already 1000mg?

Regards,
Keerthi G.

0 Clemens Ladisch over 10 years ago in reply to KEERTHI G

Guru 320720 points

Do you get the Z interrupt?
(And why are you asking this in the MSP430 forum?)
1000 mg is larger than 500 mg.
Are you aware that there are two interrupts, with different thresholds?

0 Jens-Michael Gross over 10 years ago in reply to Clemens Ladisch

Guru 227245 points

IIRC, an interrupt is only triggered, if acceleration changes from below the threshold to above the threshold. Since z-Axix already has 1g when programming the interrupt, you won't get one, unless you e.g. flip the sensor.

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Accelerometer doesn't produce interrupt for horizontal movement