A couple months ago a post circulated about how you could get a cheap head mounted display (HMD) from Wild Planet’s Spycar toy. It was an RC car with a video transmitter. Replacement headsets for the toy could be purchased for $25 and that would get you a 300×225 monochrome display. It has a stereo minijack for a composite video signal and power. Bre gave me one of these and a pair of welding goggles. I tried to stuff the HMD inside the goggles, but it didn’t work out… Nevertheless, i did learn exactly how tiny this gear is.
First I made a schematic for the adapter. It has an RCA connector for composite video input, 9V for power, and a stereo jack for the HMD’s connector.
The video signal is on the ring of the connector and the power is on the tip.
The display worked well with my N95 and I had the intention of using it with Qik since it displays chat messages in the screen while you’re recording. I needed to take the casing down more to get it into the goggles though. I thought “surely, it doesn’t need that whole lens stack”.
Well, it does. You can see the back light LED on the circuit board. On the right is the diffuser box and the left is the lens stack. In the middle is the tiny display, pretty much too tiny to do anything else with besides the current application. This is a standard arrangement and which you can see in this teardown of another HMD. Oh well, not to worry, I did learn something, and I might use it in the future.
3 thoughts on “HMD internals”
I have one of these guys hanging on my wall, waiting for just the right project – I had a great idea last night while I was playing a show and couldn’t remember the chords – perhaps scroll chord changes in my eye, with the bonus of looking like a robot on stage!
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