Built this circuit and it detects grain of sugar falling on my desk:
http://davidhoulding.blogspot.com/2014/02/high-sensitivity-vibration-sensor-using.html
1) Can the circuit above be modified to operate at 3.3V and give an output between 0-3.3V?
2) I would like to use the HIGH output of the comparator to momentarily pull the Reset pin of my micro-controller LOW, so to wake it up from deep sleep and run it's code.
I need the Reset pin to stay HIGH for a couple minutes while the code is running. I can set a GPIO pin HIGH to keep the "switch" open until the code has run, for example (dont know how exactly).
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Here is what I tried on Falstad with an NPN transistor (the output from the lM324 comparator on the left):
https://tinyurl.com/yyb5avjb
https://tinyurl.com/yxd89cdy
Maybe i could keep the capacitor from discharging by connecting it to a GPIO set to HIGH as soon as the microcontroller wakes up; then the GPIO would be set LOW just before the uC deep sleeps again, the capacitor would discharge and wait for another trigger from the LM324.
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thanks in advance
http://davidhoulding.blogspot.com/2014/02/high-sensitivity-vibration-sensor-using.html
1) Can the circuit above be modified to operate at 3.3V and give an output between 0-3.3V?
2) I would like to use the HIGH output of the comparator to momentarily pull the Reset pin of my micro-controller LOW, so to wake it up from deep sleep and run it's code.
I need the Reset pin to stay HIGH for a couple minutes while the code is running. I can set a GPIO pin HIGH to keep the "switch" open until the code has run, for example (dont know how exactly).
-------
Here is what I tried on Falstad with an NPN transistor (the output from the lM324 comparator on the left):
https://tinyurl.com/yyb5avjb
https://tinyurl.com/yxd89cdy
Maybe i could keep the capacitor from discharging by connecting it to a GPIO set to HIGH as soon as the microcontroller wakes up; then the GPIO would be set LOW just before the uC deep sleeps again, the capacitor would discharge and wait for another trigger from the LM324.
------
thanks in advance
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