Question regarding an accelerometer

Projects General Guidance
1

Hello-

Hope you are all having a wonderful day so far.

I am looking to add an accelerometer sensor to my Arduino project but I have a few questions first. I will first give you a bit of information on my project and why I need an accelerometer. There will be vibrating motors inside of a pillow I am using and I want my pillow to have the function of when I shake my pillow the vibrating motors will stop. My questions are the following:

  1. Will there be any problems with using an accelerometer inside the pillow while it is vibrating? Because I don't want the vibrating motors to trigger the accelerometer or interfere in someway.

  2. If I am able to use the accelerometer, do I need to program the Arduino to analyze the accelerometer data and only trigger the shutdown function once the accelerometer is activated with a particular level of shaking force by the user when he shakes the pillow to shut the motors down?

Thank you for reading and for your replies!

2

I want my pillow to have the function of when I shake my pillow the vibrating motors will stop.

Just use a switch to turn off the motors. Accelerometers detect vibrations, so vibrating motors will interfere.

3

Because I don't want the vibrating motors to trigger the accelerometer

Well, that is what will happen. To what extent (i.e. how much acceleration you measure), you will need to experiment to determine.

  1. If I am able to use the accelerometer, do I need to program the Arduino to analyze the accelerometer data and only trigger the shutdown function once the accelerometer is activated with a particular level of shaking force by the user when he shakes the pillow to shut the motors down?

Of course.

4

Yes, that is what I figured I would have to eventually do. Measure a certain acceleration force that will cause the motors to shut off so the vibrations themselves do not shut the motors off. Thanks for your reply!

5

PaulS:
Well, that is what will happen. To what extent (i.e. how much acceleration you measure), you will need to experiment to determine.
Of course.

I have another quick question if you don't mind me asking. Is there a certain accelerometer you can recommend for my project. I would want the shake force of the pillow to be fairly strong and the motion range to be wide about 2-3 feet.

6

I would want the shake force of the pillow to be fairly strong

The vibration caused by the motors? Or the vibration caused by the pillow user throwing it across the room?

and the motion range to be wide about 2-3 feet.

An accelerometer measures the rate of change of velocity. This has nothing to do with distance.

7

The throw of the pillow. For example a light to medium shake.

8

So, it appears that the user will (be expected to) shake (accelerate) the pillow harder than the vibration motor does. An accelerometer could detect the difference.

9

You control the motors with the Arduino, correct? You know when the motors are vibrating.
The readings from the accelerometer will have a different characteristic when the motors are
vibrating (higher frequency, smaller amplitude) from when you shake the pillow.(low frequency, high amplitude).
X, Y, and Z axes should also have significantly different values between the two conditions.
Should be no problem to distinguish one from the other.