Hey,
First post. Yay.
At the moment I'm designing a project which requires a reading a vibration sensor, something like this:
540626 on farnell.com (can't post URLs yet)
or
rapidonline.com 78-0768
Going by what I can gather, vibration causes the sensor to go into an unstable state. The datasheet says "the sensor reacts when disturbed by going into a fleeting change of state (i.e. n/o to n/c or vice versa). The settled state will be random unless mounting attitude is chosen for a n/c output".
I want to read this with a small microcontroller (a PIC10F, most likely), and I want to be able to detect when it is "disturbed". Given the rather awkward output, and my rather limited microcontroller capabilities, I'm going to need some kind of conditioning first.
I was thinking of having it input into an inverter to buffer the output, with a feedback loop to stabilise it. Then in theory I would get a 1 when there is vibration, and a 0 when there is none. I would then connect to a simple SR flip flop made from some NAND gates, and then use the micro to poll the Q output and clear the flipflop. I'd then use the micro to keep a running average.
I'm a tad worried about the signal conditining though, and I'm not entirely sure I understand when they say "fleeting change of state".
Does anyone have experience with such sensors that they could share?
Cheers,
First post. Yay.
At the moment I'm designing a project which requires a reading a vibration sensor, something like this:
540626 on farnell.com (can't post URLs yet)
or
rapidonline.com 78-0768
Going by what I can gather, vibration causes the sensor to go into an unstable state. The datasheet says "the sensor reacts when disturbed by going into a fleeting change of state (i.e. n/o to n/c or vice versa). The settled state will be random unless mounting attitude is chosen for a n/c output".
I want to read this with a small microcontroller (a PIC10F, most likely), and I want to be able to detect when it is "disturbed". Given the rather awkward output, and my rather limited microcontroller capabilities, I'm going to need some kind of conditioning first.
I was thinking of having it input into an inverter to buffer the output, with a feedback loop to stabilise it. Then in theory I would get a 1 when there is vibration, and a 0 when there is none. I would then connect to a simple SR flip flop made from some NAND gates, and then use the micro to poll the Q output and clear the flipflop. I'd then use the micro to keep a running average.
I'm a tad worried about the signal conditining though, and I'm not entirely sure I understand when they say "fleeting change of state".
Does anyone have experience with such sensors that they could share?
Cheers,