Night Vision Goggles for Google Cardboard

Disclaimer: The use of this device is intended for entertainment, education, and scientific use only; not for spying and/or surveillance. The "spy gadget" features were added to the app just for fun and would serve no practical purpose for real surveillance use. Please check your local laws for use of night vision devices.

By making use of the infrared sensitivity of modern smartphones and the Night Vision for Cardboard app by Defpotec Studios, you can turn your Google Cardboard headset into working night vision goggles. Please don't expect the results of professional night vision equipment, as those can cost hundreds of dollars and use more advanced techniques, but you should be able to expect decent results if you are willing and able to modify your phones camera by removing it's IR-filter.

These instructions only require light solder work and a basic understanding of electronics. The IR-Filter mod is only briefly covered here as it is a much more advanced project.

This particular design was chosen to create a Night Vision add-on for Google Cardboard which will not in any way modify the actual Google Cardboard Headset. If you are making your own design, please feel free to cut, screw, or glue these components directly onto your headset if you so desire.

Note: One of the optional improvements covered at the end, will require cutting into your Google Cardboard. Also, if your particular headset does not have a hole for the camera, then you have to cut one.

Not all phones are created equal. Some may provide better results than others. In general, the better the phone the better it will be at blocking infrared.

Materials:

• Google Cardboard Headset
• Infrared LED (IR-LED) Circuit Board from security camera. <$5 eBay
• Battery holder for 8 AA(or 2 x4 AA holders side by side) <$5 Radio Shack, digikey.com, mouser.com, etc...
• Hookup wire
• Switch or button
• Cardboard
• Paperclips
• Something to hold it all together (screws, rubber band, Velcro, glue, wire-ties, etc...)
• Night Vision for Cardboard app.
  -Free on the Google Play store

Tools:

• X-ACTO Knife
• Wire Cutters
• Wire strippers
• Soldering Iron

First, Using scissors and an X-Acto knife, I cut a piece of cardboard into a shape which will hold all the components. The main rectangle shape is the same size as the battery holder and also fits nicely on top of the Google Cardboard. The exact dimensions will vary depending on your Battery Holder, Button or switch, and IR board.

Then I cut a hole for the push-button just big enough so the the button could be screwed in tight and used the edge of a table as a straight-edge to add the creases.

This particular IR LED board runs on 12V and has a plug labeled +12 and Gnd, Not having the plug, I simply solder a red and black wire to the pads on the other side of the board.

These IR boards are for security cameras and you can usually get them for less than $5 off eBay or similar sites. You could also build your own and even use super-bright IR LEDs for even better results.

The darker cylinder on the board is a light sensor which causes the LEDs to not come on unless it's dark. This normally isn't a problem for night vision, but if you like, you could simply cover the sensor so the LEDs will always light when they have power.

The button was screwed into the hole and a nut added to hold it in place.

The LED board could have been mounted with screws, but I opted to use a wire tie. Using a small screwdriver, I punched holes lined up with the mounting holes in the circuit board and into the cardboard. I then pushed the wire tie through and twisted it behind.

Next, I soldered the positive(+) wire from the LEDs to the switch, and another wire from the switches other terminal which will later go to the batteries positive terminal.

To help hold the shape of the cardboard around the switch, I straightened 2 paperclips and pushed them into the corrugation of the cardboard, one on each side of the switch. Then I bent the paperclips inside the cardboard at 90 degree angles.

To hold down the cardboard for the LEDs, I straightened 2 paperclips, bent them at 90 degree angles, and taped them underneath.

Next, I glued the battery holder to the top and held it in place with clamps while the glue dried. I used a hot glue gun, but other glues should work just as well.

Then I soldered the negative(-) wire from the LEDs to the negative terminal of the battery holder. Then the positive wire from the switch to the positive terminal of the battery holder. Some tape helped to hold the wires in place.

At this point, to make sure everything is wired up correctly, you can add batteries and press the button while viewing the LEDs through your phones camera. Even without any modifications to your phone they should appear to be glowing brightly on your phone screen but you should not be able to see them with your naked eyes.

Finally, I used a rubber band to hold the unit to the top of the Google Cardboard.

Testing: Download and run the Night Vision for Cardboard app and make sure it's in headset mode. There should be 2 images side by side. Place the phone in your Google Cardboard and add the Night Vision attachment you just made. Turn out the lights and activate the IR LEDs. Due to an IR-blocking filter on the camera lens, the range will likely be limited. Also, in the apps options, try both checking and un-checking the "USE IR"* checkbox to see if that makes a difference. It should make the image be brighter by basing the image brightness off of a cameras IR response curve instead of normal lighting. You can also go into "Advanced Options" and turn off the HUD features which may help you see fainter objects through the camera. If the results are still not what you like, then please continue on to the next steps.

*The "Use IR" option creates a green screen effect based on the frequency response of a phones camera in the IR range. This should result in a slightly brighter image. Also, the green screen is not just for effect. The human eye is much more sensitive to green than purple(which IR looks like in a phone).

Build a periscope:

The front camera, or selfie cam, of most phones is typically much more sensitive to IR due to a lower quality(or no) IR Blocking filter. By using it instead, you can usually expect better results. The problem, however, is that it's facing the wrong way. The solution? Build a simple reverse periscope using a piece of cardboard and 2 mirrors. The only downside to this is that it requires cutting a hole(or at the very least, 2 slits) in the side of your Google Cardboard.

First, determine the location of your front facing camera. To help with sizing and spacing as you build this piece, it may be helpful to turn on your camera and change it to front facing camera mode.

Next, take a small piece of cardboard and fold it 90 degrees. You will need to test on your phone to ensure the spacing and size. Glue a small mirror onto each inside face as shown in the picture. To help hold its shape, tape or glue 2 triangles to the top or bottom. Test on your phone to make sure it will correctly before moving onto the next step.

To make it removable, I cut out another pair of triangles and cut them each in 2, trimming them to act as groves. These were glued to top and bottom.

Next, cut 2 slits along the edge of your Google Cardboard, on the side with the front facing camera to fit the piece you just made. Either cut off this piece or simply fold it over. You may have to remove the magnets, if your headset has them. Then push the periscope into the hole along the groves. Keep everything square and flush and tape or glue it in place if needed.

Run the Night Vision for Cardboard app and on the options screen, select the "Use Front Camera" checkbox. Install your phone in the headset and you should now be seeing through the front camera instead of the main camera. Turn off the lights, activate the IR and check if you can see better than with the front camera.

More IR
By adding another IR LED board, you can double the amount of IR visible to your camera. You can also use Superbright IR LEDs for even more illumination.

For best results, you can remove the IR blocking filter from your camera. This will effectively turn your device into an IR camera and should be very good for night vision. It does however require you take apart your phone, so it is only recommended to those who actually know what they are doing. This modification is done at your own risk.Defpotec Studios will not be held accountable for any damage done to your device.

This process is much more advanced to be described here, and varies from phone to phone, but it essentially involves taking apart your phone and removing the IR Filter, or replacing your phones camera module with one already having the filter removed. The links below are an excellent resource if you wish to attempt this modification.

There are also vendors who sell, or can modify your phone for IR viewing.

For more information on phone modification, purchase, and other general smartphone IR viewing, please visit http://www.eigenimaging.com

Instructions for how to preform this mod can be found on the site as well...
https://www.eigenimaging.com/pages/modify-google-g...

Eigen Imaging Inc, is in no way associated with Defpotec Studios, or the Night Vision for Cardboard App.