Try raising or lowering this value to increase your sensor's overall sensitivity. In the code below, the incoming piezo data is compared to a threshold value set by the user. Without it, the analog pin might not be capable of reading the piezo's signal. The placement of the resistor is used to save the piezo from damage from extra current. The piezo is attached to analog pin 0 with a 1 Megohm resistor in between the two legs. Piezo sensors work best when firmly pressed against, taped, or glued their sensing surface. These will look like a metallic disc, and are easier to use as input sensors. It is possible to acquire piezo elements without a plastic housing. Additionally, connect a 1-megohm resistor in parallel to the Piezo element to limit the voltage and current produced by the piezo and to protect the analog input. Connect the black wire (the lower voltage) to ground and the red wire (the higher voltage) to analog pin 0. Piezos are polarized, meaning that voltage passes through them (or out of them) in a specific direction. Open the serial monitor to see this text. If the sensors output is stronger than a certain threshold, your board will send the string "Knock!" to the computer over the serial port. The sketch reads the piezo output using the analogRead ( ) command, encoding the voltage range from 0 to 5 volts to a numerical range from 0 to 1023 in a process referred to as analog-to-digital conversion, or ADC. Piezos can be used both to play tones and to detect tones. Similarly, when you put a voltage across a piezo, it vibrates and creates a tone.
Piezo vibration sensor how to#
This tutorial shows you how to use a Piezo element to detect vibration, in this case, a knock on a door, table, or other solid surface.Ī piezo is an electronic device that generates a voltage when it's physically deformed by a vibration, sound wave, or mechanical strain.