Wireless IoT Door Open/Closed Sensor

Open and closed using the mcModules

In this project we're going to show you how to easily use the built-in magnetic (reed) switch on the mcModule120. With the mcModule case (which includes two neodymium magnets), you can easily setup a wireless, coin-cell operated, door sensor (or anything else that opens) and be alerted if the door opens, see real time status and even count the number of times the door was opened!

The project includes information and code for sending the information to Android using MQTT, IFTTT and an IoT cloud service, Losant!

How the platform works:

The mcThings platform includes 2 main components: mcModules and mcGateways. A powered and connected mcGateway creates the mcAir network (up to 200m range under optimal conditions) and bridges the information between the mcModules (within range) to and from the Internet. Using the IDE (mcStudio) and mcScript (ultra-low power programming language - a subset of VB.NET) allows you to wirelessly connect, debug and program modules with your customized scripts.

Note: You also require an mcDongle to complete firmware updates on the modules/devices and gateways! We recommend looking at the mcModule120 Dev kit which includes everything you need to get going!

Using the Reed switch

Using the mcModule enclosure, you can easily install the module to a door/window/etc and place the magnet clip so that it lines up with the module when the object is closed. You can also use your own magnets! We recommend a strong magnet like neodymium. If you are building a customized enclosure or have a unique object that you want to use the reed switch with, this is a good option.

Android using MQTT - Video and Code

Similar to one of our other projects, we're going to push the information to an MQTT client app on an Android phone to see the status in real-time!

Check out the below video and code for putting this together as you'll need to setup your gateway and your MQTT broker properly to push information to your phone:

Code:

Class ProductionRoom/YOURPROJECTNAMEHERE    
 Shared Event ReedSwitchChanged()
   Dim payload As ListOfByte = New ListOfByte 
   Dim payString As String = ""
   If ReedSwitch = True Then 
    LedRed = True  
    payString = "Open"  
   Else        
    LedRed = False  
    payString = "Closed"    
   End If      
   payload.Add(payString) 
   Lplan.Publish("mcThings/ProductionRoomDoor/YOURTOPICNAMEHERE", payload) 
   Thread.Sleep(10000) 
   Thread.ClearHardwareEvent()  
   Dim uptime As Integer = Device.Uptime() 
 End Event   
 Shared Event CheckVoltage() RaiseEvent Every 2 Days  
     Dim BattVolt As Short = Device.BatteryVoltage  
    If BattVolt < 2200 Then  
     Lplan.IFTTT("YOURIFTTTMAKERKEYTHERE", "YOUREVENTNAMEHERE") 
    Else                   
    End If
             
 End Event
End Class

We also included a bit of programming to check the battery voltage every 2 days and send a message to the maker channel on IFTTT if below 2.2 volts (above is measured in millivolts).

IFTTT - Code

Below is code to setup a message to be sent to IFTTT if the door is opened and closed. Again we added a battery voltage check. Using IFTTT allows you to send the information to a ton of different services! We usually use notifications via the IFTTT Android app but you could receive an email, log the information into a spreadsheet, etc!

Class IFTTTAndroidDoor   
   Shared Event ReedSwitchChanged() 
       If ReedSwitch = True Then  
           LedRed = True   
           'Enter your maker channel event name such as 'doorOpen' 
           Lplan.IFTTT("YOURIFTTTMAKERKEYHERE", "doorOpen")   
       Else         
           LedRed = False   
           'Optional to add the below closed function as well 
           Lplan.IFTTT("YOURIFTTTMAKERKEYHERE", "doorClosed")  
       End If       
       Thread.Sleep(10000)  
       Thread.ClearHardwareEvent()   
       Dim uptime As Integer = Device.Uptime()  
   End Event   
         'check the battery voltage every 2 days 
   Shared Event CheckVoltage() RaiseEvent Every 2 Days   
       Dim BattVolt As Short = Device.BatteryVoltage   
       If BattVolt < 2200 Then   
           Lplan.IFTTT("YOURIFTTTKETHERE", "ProductionRoomBattery/YOURTOPICHERE")  
       Else                    
       End If 
   End Event  
End Class  

Losant - Code and Video

Similar to our other Losant project, we'll be sending door open/closed status and count to a dashboard as we as temperature and battery information (Check out the LIVE Dashboard!).

 Class LosantDoor
  
  
    // Device ID of Peripheral in Losant
    Const LosantDeivceId As String = "YourLosantDeviceIDHERE"
    // MQTT topic in Losant
    Const LosantTopic As String = "losant/" + LosantDeivceId + "/state"
  
    Shared _doorState As String
    Shared _doorcount As Integer
  
    Shared Event Boot()
        _doorState = "Open"
        _doorcount = 0
    End Event
  
    Shared Event ReedSwitchChanged()
        'debounce interrupt
        Thread.Sleep(100000)
        Thread.ClearHardwareEvent()
        LedRed = True
        If ReedSwitch = True Then
            _doorState = "Open"   
            _doorcount = _doorcount + 1
        Else
            _doorState = "Closed"
        End If
        sendMQTTData()
        LedRed = False
    End Event
  
    Shared Event CheckSensors() RaiseEvent Every 60 Seconds 
        sendMQTTData()
    End Event
  
    Private Sub sendMQTTData() 
        Dim tempTMP102string As String = TempSensor.GetTemp().ToString()
        Dim battShort As Short = Device.BatteryVoltage()
        Dim battFloat As Float = battShort / 1000
        Dim battString As String = battFloat.ToString()
  
  
        // Create data JSON object 
        Dim dataJson As Json = New Json
        dataJson.Add("battery", battString)
        dataJson.Add("temperature", tempTMP102string)
        dataJson.Add("doorState", _doorState)
        dataJson.Add("doorCount", _doorcount)
  
  
        // Create Losant preferred JSON object
        Dim losantPayload As Json = New Json
        losantPayload.Add("data", dataJson)
  
        // Publish to Losant MQTT
        Lplan.Publish(LosantTopic, losantPayload.ToListOfByte)
  
    End Sub
  
End Class

Below is a video to help you walk-through setting up the mcThings platform with Losant so you can start sending tons of information and display it in the awesome dashboard!

Sending the information to other services

You can modify or write your own code to send the information to another service if you wish! Because you can send the information out via MQTT or via IFTTT, there are numerous applications that can display, store, visualize and analyse the information.

Thanks for reading! Please become a member on our hub so that you can be alerted when we post new projects (many more to come!)