SW420 Vibration sensor

In this example we are going to connect the Raspberry Pi or alternate board to vibration sensor.

This example is super easy after doing the infrared motion detection with the HC-SR501 in a previous example, since basically same code will work. I found this sensor to be excellent, it gives readings when I expect it to and not readings when I don’t expect it to. And you can configure the sensitivity of it a bit with the settings potentiometer on it.

SW420 vibration sensor

DISCLAIMER

We do not take any responsibility for possible errors in the guide or errors that you might do wiring it up. Incorrect wiring can result in damaged sensor or damaged Raspberry Pi.

Pieces we use:


This sensor comes with good markings so its very easy to wire it.

Warning

When measuring up this sensor then it shows the digital output will have same voltage as the input. Meaning you  have to connect 3.3 V to the input when using with the Raspberry Pi.

The potentiometer on the board allows you to adjust the sensitivity of the DO output. 

The board has PWR_LED and a DO_LED. 

The sensor will have the PWR_LED showing that it is turned on,  and the DO_LED lights up when it vibrates, making it send HIGH signal, while when there is no vibration then it will be sending LOW.


Spec on this sensor is:

If you are not familiar with working with a breadboard or on how to place a cobbler on the breadboard then click here bellow

Breadboard

Raspberry Pi pin layout

If you need more information about the GPIO headers on Raspberry Pi or other boards then click bellow.

Raspberry Pi Pin guideOrange Pi One Pin guideOrange Pi Pin guide for most H3 modelsOrange Pi Zero 3 Pin  guideOrange Pi 5 Plus Pin guideRock 64 Pin guide

Raspberry Pi pin layout

The Xojo Code

Private mLineRequest As Gpiod.LineRequest

And then Opening event for the Window:

Sub Opening() Handles Opening
  try
    using Gpiod
    
    var chip as Chip = Chip.Open("/dev/gpiochip0")
    
    var lineRequest as LineRequest = RequestInputLine(chip, 5, "vibration-sensor")
    
    lineRequest.RequestReadEdgeEventsAsync(5, true, AddressOf LineMonitorCallback)
    
  catch e as GpiodException
    MessageBox(e.Message)
  end try
End Sub

Helper function to set up the line

Public Function RequestInputLine(chipHandle as Gpiod.Chip, lineOffset as UInt32, consumer as String) As Gpiod.LineRequest
  using Gpiod
  
  // Exceptions will be caught by the caller method
  
  var reqCfg as RequestConfig = nil
  
  var setting as new LineSetting()
  setting.Direction = Gpiod.Direction.INPUT
  setting.EdgeDetection = Gpiod.LineEdge.FALLING
  setting.Bias = Gpiod.LineBias.PULL_DOWN
  
  var lineCfg as new LineConfig()
  lineCfg.AddLineSetting(array(lineOffset),setting)
  
  if consumer <> "" then
    reqCfg = new RequestConfig()
    reqCfg.Consumer = consumer
  end if
  
  return chipHandle.RequestLines(reqCfg, lineCfg)
End Function

Callback for our events:

Public Sub LineMonitorCallback(edgeEvent as Gpiod.EdgeEvent)
  lstEvents.AddRow(if(edgeEvent.EventType = Gpiod.EdgeEventType.RISING_EDGE, "Rising", "Falling"))
  lstEvents.CellTextAt(lstEvents.LastRowIndex, 1) = edgeEvent.LineOffset.ToString()
  lstEvents.CellTextAt(lstEvents.LastRowIndex, 2) = edgeEvent.LineSequenceNumber.ToString
  lstEvents.CellTextAt(lstEvents.LastRowIndex, 3) = edgeEvent.TimestampNs.ToString()
End Sub

Getting the code

You can find this example code at Example code for GPIO guides.