Gyro sensor with wake-up

[davorin]

EHLO (o;

Is someone aware of a gyro sensor which could be waked up through a simple knock on it?

Most I have seen need to be running, though they offer a low-power mode to detect xyz axis acceleration...
but I would need a sensor which draws current in the range of few uA and generates an interrupt as soon acceleration is detected...

Or any other idea how to wake up a circuit with knocking on it?

Idea is to make a control knob which reacts  on taps to it...



kiitoksia (o;

[cgroen]

Do you mean gyro (measuring angular movement) or accelerometer (measuring acceleration) ?
I use LIS3DH from ST for detecting single and double tap, works pretty good:
https://www.st.com/en/mems-and-sensors/lis3dh.html

[davorin]

The same sensor I used for testing....

What is your experience with power consumption and detecting movements?
Not sure if the low-power mode would detect any taps on it when using 1Hz ODR....

[cgroen]

I use it for detecting movement (when rest of system is shut off). Power consumption is very low, datasheet has the numbers

[davorin]

But don't you need something to read out the sensor continuously to detect changes or does it by  it self?

[cgroen]

Oh no,
you set the threshold and time, and it detects the condition automatically. It can the raise an output to signal that condition to to the rest of the system (som of my devices uses this signal to turn on powersupply of the main processor, in other systems I use it to make a wakeup signal to the processor to wake it from Deepsleep)