RFID Door Unlock Using Arduino

You see that our hex code is 12 73 E5 56, write that down and now scan two more tags.

Arduino Code Explained

Now open doorcontrol.ino, we will need to change the RFID tag values. Change RFID Tag 1, 2, 3 to the HEX values we got from the previous steps. Look for this section in the code

// Change the HEX values to the tags you scanned
byte tag1[4] = {0x12, 0x73, 0xE5, 0x56}; // RFID Tag 1
byte tag2[4] = {0x02, 0x30, 0xE4, 0x56}; // RFID Tag 2
byte tag3[4] = {0xB2, 0x0F, 0xE5, 0x56}; // RFID Tag 3

When the code is ran it reads the RFID tag. It then compares the UID to the three stored tags. If it finds a match it checks that it is in the correct order. Tag 1 needs to be the first scanned.

// Checks if it matches RFID Tag 1
    if (rfid.uid.uidByte[0] == tag1[0] &
        rfid.uid.uidByte[1] == tag1[1] &
        rfid.uid.uidByte[2] == tag1[2] &
        rfid.uid.uidByte[3] == tag1[3])
    {
      if (tag1count == 0 & tag2count == 0 & tag3count == 0)
      {
        tag1count = 1; // Sets Tag 1 to unlock

Then Tag 2 and finally Tag 3. If at anytime the order is wrong it sets the status back to zero and you need to start over. Similar to how a combination lock works.

Once the program sees the correct combination it will unlock the door. Once the Lockitron moves the deadbolt in it goes back to a starting position. This allows the door to also be manually opened with a key or by turning the knob.

Creating the Windows app

I used Visual Studio 2015 to create the app. I followed the Windows Remote Arduino tutorial but made a few changes for using WiFi and for my needs. Things I did different was name the buttons Lock and Unlock and make them larger and easier to see.

<Button Name="LockButton" Click="LockButton_Click" Grid.Row="0" IsEnabled="False" HorizontalAlignment="Stretch" Height="300" FontSize="96">Lock</Button>
        <Button Name="UnlockButton" Click="UnlockButton_Click" Grid.Row="1" IsEnabled="False" HorizontalAlignment="Stretch" Height="300" FontSize="96" Margin="0,10,0,0">Unlock</Button>

I also changed what happens when the button is pressed. I want it to make a pin HIGH but after 10 seconds go back to low.

private async void LockButton_Click(object sender, RoutedEventArgs e)
        {
            arduino.digitalWrite(6, PinState.HIGH);
            await Task.Delay(10000);
            arduino.digitalWrite(6, PinState.LOW);
}

You will also need to change the IP address if using my example to the address you got earlier in this tutorial from your Arduino MKR1000. The reason I am putting the IP address in the code instead of a box that would allow you to enter it in is that when I want to unlock my door I want to make it as easy as possible. I don’t want to need to type in an address or remember it.

connection = 
new
 NetworkSerial(
new
 Windows.Networking.HostName(
"192.168.1.170"
), 
3030
);

I also made a video on the steps I went through to create an app that blinked the Pin 6 LED on and off.

Once I had the code done I created an app package so I could load it on to my Windows Phone I found this tutorial helpful for creating the app package. Once you have the app package created you can run it through the Windows App Certification Kit to see if it passes, this isn’t required. It is neat to see though.

This app passed the test

Loading App on my Phone

Once I had the app I opened settings on my Windows phone and went to the “For Developers” section and enabled developer mode. Under Device Portal it gives a Wi-Fi IP address. Open that link in your web browser on pc.

Windows Phone settings

Browser window

At the browser window select your app package that we made previously. Should be in a location similar to

C:\Users\Kirby\Documents\Visual Studio 2015\Projects\Door Control\Door Control\AppPackages

Then also select the dependencies. Clicking Add Dependency after you have one selected will add another selection box so you can upload multiple dependencies. Then click Go to upload to the phone. If everything goes good you should see the app on the phone now.

We see the app Door Control now on the phone

Using the Windows App

When you use the app it bypasses the need to enter a correct RFID combination. From the app you can press either the Lock or Unlock button. You then have 10 seconds to scan any RFID tag then to trigger the Lockitron.

Watching it Work

Here is video of it working with the RFID code and also when using the app. So this project actually works and isn’t a concept. Using the Lockitron also allows you to still unlock the door manually.

https://youtu.be/slbPu6EdhVc

Helpful Links

Here are some links that I found helpful when learning this project.

• https://learn.sparkfun.com/tutorials/lockitron-hardware-hookup-guide
• https://learn.adafruit.com/open-sesame-a-sms-controlled-door-lock
• https://ms-iot.github.io/content/en-US/win10/WRA.htm
• https://msdn.microsoft.com/en-us/library/hh454036.aspx#BeforePackaging
• https://blogs.msdn.microsoft.com/madenwal/2015/11/24/generating-your-tileicon-image-assets-for-windows-10-uwp-using-photoshop-actions/
• https://github.com/ms-iot/remote-wiring-experience
• https://github.com/miguelbalboa/rfid

End Notes

Thanks for looking at my tutorial. I hope this was easy for you to understand, its my first one on this site. This project was a fun one for me to learn. I had this Lockitron sitting in my parts box for a while.

Schematics

Wiring

This is the wiring for this project

Read more : RFID Door Unlock