Vibration Switch

A project log for The Smart Letterbox

Attach a device to an existing letterbox that will send a push notification when a letter or package is inserted

Tony KambourakisTony Kambourakis 01/08/2016 at 01:121 Comment

Tried the Adafruit vibration switch (purchased from Core Electronics) to see if it can be used to detect the insertion of a letter/package in the letterbox. It comprises a metal pin with a soft spring coiled around it. When it is moved the coil touches onto the pin, essentially behaving as a switch.

I connected it to a resistor and LED to observe the waveform when it makes contact.

It generates quite a few pulses due to the bounce. It doesn't look like the pulse has a large enough rising edge to trigger the GPIO of the MCU. This needs to be tested.

Here is a shot of the inside of the vibration sensor


Tony Kambourakis wrote 02/07/2016 at 14:22 point

Tests demonstrated this vibration sensor produced a significant enough change to be detected by the MCU input. 

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