Make the DODOcase VR / Google Cardboard Switch Work - Samsung Galaxy S3 Phone




Introduction: Make the DODOcase VR / Google Cardboard Switch Work - Samsung Galaxy S3 Phone

The Problem:
I had a chance to try out the DODOcase Virtual Reality Cardboard viewer which is based on the Google Cardboard project. It's a neat, fun, inexpensive way to experience immersive virtual reality. However, I have the Samsung Galaxy 3 and DODOcase VR version 1.1 which explicitly states that the S3 is only partially supported (see this page "Magnetic input not working").

The Solution:
I managed to get the switch to work for my phone, essentially by moving the magnetic switch to the opposite corner on the VR. I created this instructable in the hopes that it will help others. (Note, DODOcase now provides VR version 1.2 which has a capacitive touch button mechanism which is supposed to work with all devices including iPhone 6 and Android phone)

Parts, Supplies and Tools needed:

  • spare cardboard, I used the box the DODOcase VR came in
  • tape
  • knife - xacto or pocket knife
  • pen
  • Magnetic field measuring app such as MagnetMeter

Step 1: How Should the Switch Work for My Phone?

The "switch" on the DODOcase VR / Google Cardboard V1.1 consists of a cylindrical magnet on the inside of the viewer and a magnetic ring (which looks like an ordinary washer) on the outside left-hand side of the viewer. When using many of the VR apps, you simply slide the washer down and release it to do things such as select menu options or shoot aliens. How does sliding a little metal washer cause anything to happen in my phone app? Well, one of the sensors on most smartphones is a magnetometer, used to measure the strength of a magnetic field (and normally help with compass direction). Sliding the magnetic ring changes the strength of the magnetic field and that's a signal the phone app can use.

The Hypothesis

Since Google specifically calls out the Samsung Galaxy 3 as not supported for magnetic switch input, I did some searching and found that some people suggest the Magnetometer is on the wrong side in the S3 and perhaps the switch could be moved to the other side to make things work.

The Experimentation

To test things out, I searched google play for a magnetometer app and came up with the app MagnetMeter. This app worked well for what I needed, just a good indication of the strength of the magnetic field when the switch was in the up and down position. The app had a nice setting to avoid sleepmode, but it also seemed to crash occasional. While testing with this app I turned off the NFC setting on my phone to avoid having the DODOcase software start up.

I put the phone in upside down, so my phone's magnetometer would be near the switch. With a little experimentation I found that the sliding the ring does indeed change the strength of the magnetic field, and apps (though sometimes upside down) would now respond to the switch. Theory proved, let's move on to moving the switch

Step 2: Move the Magnetic Switch

To move the switch I simply unfastened the double stick tape holding the magnet side of the VR viewer. I bent this the left side of the viewer down and traced it on a scrap of cardboard (actually as you can see the scrap is the box the DODOcase VR came in). Then I used a pocket knife to cut out the hole and make a piece the correct size to serve as a new layer for the right side of my VR viewer.

I used tape to fasten the magnet and new right hand layer in place (and to refasten the left hand side of the viewer). Once reassembled and with the phone in it's normal position, I found apps such as Google Cardboard and Cardboard Catapult VR app which rely on the magnetic switch now respond correctly. (of course I now have to use my right thumb and slide up instead of my left forefinger sliding down)

Thanks for checking out my Instructable and good luck on all your projects!



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    27 Discussions

    HI i need one help pleeessss tell how make samsung grand prime google cardboard qr code generator size......

    Also there is a best Viewer Profile QR ive generated for configuring this vr dogocase with nexus 5


    thank you

    You can also simply download a screen rotation app such as "Rotation Anywhere" and simply fix this issue by rotating screen digitally. It worked for me.

    Thanks! That fixed the magnet switch problem. Unfortunately, the majority of Google Cardboard apps/demos only render on a small patch of screen, using only a quarter of the available screen. This defect makes it unusable (regardless of how much eye-crossing you try). Many non-Google demo's still work though (Tuscany and Jurassic, for example). Anybody figure out how to get the Google Cardboard demo's to display full (half) screen?

    6 replies

    sorry, havent seen that problem. Can you add a screen capture or list a specific app that doesnt work I can try it out, thanks

    Thank you for the quick reply. The attached screenshot shows what 90% of all Cardboard apps look like. they "work" with regard to proper motion (rotate left and the image rotates). Very smooth too! Just, the images are so small and can't be used with the Cardboard headset. This is the Google Earth demo that comes with the Google Cardboard app. The phone is the Samsung Galaxy S3 model number SPH-L710, running Android 4.4.2. I don't have any mods or roots running. It's stock. The red arrows indicate how large he image should be.


    Finally developed a solution to use the Google Cardboard App for Samsung Galaxy S3. You have to generate your own custom QR code. It's easy. Go to the Google page at:

    (click on the Continue button at the bottom)

    Leave everything default except change these:

    A) Inter-lens Distance, change to 100mm (yes, even though your lenses are 60mm)

    B) Change Screen Vertical Alignment to "Center"

    C) Change fields-of-view all to 55 (you can experiment with 60 as well).

    Now push the blue "Generate Profile" button.

    On your phone, startup the Google Cardboard App. Push the gear icon. Push Setup. Scroll downward. Push the button that says "Switch Viewer". Hold the phone up so your camera sees the newly generated QR code on the computer screen. Push the "back" arrow button. Enjoy Google Cardboard Apps (and many more!) on your Samsung Galaxy S3.

    Would this be necessary for the Note 4 as well? Default location of magnet is not detected with cardboard app, but firing up the magnet app it detects magnet switching easily. Annoyed that the app has trouble calibrating.

    1 reply

    Sorry I can't say for sure, I wonder if the Note 4 is kind of large to fit in the original DODOCase VR as well?? But there is an new adapter kit that they sell which allows the switch to work with virtually any phone

    Well, its supposed to be put where your phone's back touches the box, watch the speedbuild video in the beginning of this post, its the big black sticker.

    So i'm right in saying that when I hold the GS3 in my hand, the magnetometer is in the bottom left hand side, which is also why you set the switch to go upwards, and not simply mirror the original switch on the other side? Or would it matter if I had the switch popping down instead of up?

    1 reply

    Yea, im pretty sure its looking at the strength of the field and not the position of the magnet so you should be able to make it to slide down, as long as it goes closer to the sensor when sliding down, not away from it.

    Have the same problem with tha S4. But by my experimentation the problem is the magnets are too strong and it reads too high values (250 unclicked and 450 clicked) What values did you found out to work best? I might have to move the magnets a little bit back.

    1 reply

    Hmm, I would have to check, I do have an otterbox case on mine so perhaps that lowers the magnetic field a bit, ??...Oh, mine is a Galaxy S3, I thought Galaxy S4 is a supported phone....It would be interesting to know if the s4 has the sensor such that the magnet has to moved at all