Get a shutter 3D image on almost any device by syncing the display with the headphone jack. If you are developing a 3D application and wish to have a Stereoscopic display feature. ync display refresh rate with a sawtooth wave using audio out. All that is needed is a signal linked to the display's refresh rate. Device sound output can sync a signal to the refresh rate of a monitor and be used to drive glasses.
I first created a simple circuit on a breadboard that was able to create two alternating sawtooh waves with frequencies that ranged between 20-240 Hz at 5 V. The circuit was powered with 2 AA batteries.
I have some existing 3D glasses that are controlled using a wired TRS connector (Headphone Jack). I connected the output dongle from my computer, the original source of sinal for the glasses, to an oscilloscope. I then capture 3D glasses signal output using the oscilloscope as shown here.
I then created a test; a sample output signal for the glasses using a waveform generator and IC components. I tested the range of frequencies that the glasses responded to to ensure that they matched the circuit. Then I tested the circuit with the oscilloscope to ensure it created the same output as the signal generator.
Below are a photo of the glasses.
I created a "plug" for the TRS connectors (Headphone Jack) on the breadboard using exposed wire and a clip to hold the cable in place. One TRS jack come in from the display device and serves as a clock to sync the glasses. The other TRS jack is an output to the glasses to drive the LCD shudders.
This is an image of the circuit right before the power from the AA batteries is added to make the circuit mobile.
This setup will work for any display device with an audio jack. Anything from consoles to mobile devices.